The Severn Barrage
22 May 2008
Transcript of Proceedings
May 2008
Intentionally Blank
The Severn Barrage
Thursday 22 May 2008
Introduction
The Severn Barrage proposal has been in existence for many years, but the more
urgent need for low-carbon electricity generation and the adoption of legally binding
national targets for renewable energy generation mean that the proposals, together
with other tidal range power options in the Severn Estuary, are now receiving
renewed attention from Government and industry.
If the barrage were to be built, it would rank as one of the largest and most costly
engineering projects ever undertaken in the UK. Its impact on the ecology of the
Severn Estuary would be significant, but in a political environment where reducing
greenhouse gas emission is so high, a balance must be struck between the
environmental benefits and the ecological damage. A single “power plant” with a
7GW capacity will have implications for how the electricity market operates,
especially as it will be intermittent, following the tidal cycle.
Inevitably, the size and cost of such a project will bring its own project management
problems to be overcome. The UK has demonstrated that it is capable of building
single projects the size of the Channel Tunnel Rail Link, but issues surrounding the
financing, contracting and ownership of the scheme will be of paramount importance.
Programme
15:00
Registration
15:15
Chair’s Introduction – Sue Ion OBE FREng Vice President
15:20
Malcolm Wicks MP, Minister of State for Energy
15:40
Prof Roger Falconer FREng, Cardiff University – Severn Barrage Proposals,
Problems and Possible Solutions
16:10
Dr Doug Parr, Greenpeace UK – Environmental Impacts and Balances
16:40
Paul Golby, E.ON UK (TBC) – The Electricity Industry’s Response to a
Severn Barrage
17:10
Yaver Abidi, Halcrow Group – Financing and Project Management
Challenges
17:40
Discussion Chaired by Sue Ion FREng
18:00
Reception
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2
The Severn Barrage (22 May 2008)
Speaker Biographies
Dr Sue Ion OBE FREng
Dr Sue Ion was Group Director of Technology and Chief Technology
Officer of British Nuclear Fuels plc, a position she held from 1992
until 2006. Dr Ion was elected a Fellow of the Royal Academy of
Engineering in 1996 and awarded the OBE for services to the
nuclear industry in 2002. Dr Ion has held a number of non-executive
directorships associated with technology-based businesses and
consultancies. Dr Ion represents the UK on a number of
international review and oversight committees including the
International Atomic Energy Agency Standing Advisory Group on Nuclear Energy
and the Euratom Science and Technology Committee. Dr Ion is currently Vice
President of the UK's Royal Academy of Engineering and a member of EPSRC's
Council. She was formerly a member of Council of the Particle Physics and
Astronomy Research Council. She is a non Executive Director of the Board of the
Health and Safety Laboratory.
Malcolm Wicks MP
Malcolm Wicks was appointed Minister of State for Energy on 29
June 2007. Mr Wicks was previously Minister of State for Science
and Innovation (November 2006 to June 2007) and, before that,
Minister of State for Energy (May 2005 to November 2006) at the
Department of Trade and Industry. Before joining DTI, Mr Wicks was
Minister of State for Pensions (June 2003 - May 2005) and
Parliamentary Under Secretary of State for Work (June 2001 - June
2003) at the Department for Work and Pensions and Parliamentary Under Secretary
of State for Lifelong Learning at the Department for Education and Employment
(appointed July 1999). Mr Wicks was the Chairman of the Education Select
Committee from 1998 until his appointment as a Minister. He has been Member of
Parliament for Croydon North since 1992. Mr Wicks has been a member of the Social
Security Select Committee. His Private Member's Bill, now the Carers' (Recognition
and Services Act), came into force in April 1996. From 1995 Mr Wicks was the
Opposition spokesperson on social security.
Mr Wicks was educated at North West London Polytechnic and the London School of
Economics. Between 1974 and 1977, he was a university lecturer and from 1968 to
1974 a social policy analyst at the Home Office. He was Director of the Family Policy
Studies Centre before entering Parliament. He is the author of several books and
reports on aspects of the welfare state.
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Professor Roger Falconer FREng
Roger Falconer is Halcrow Professor of Water Management and
Director of the Hydro-environmental Research Centre in the School of
Engineering at Cardiff University, U.K. He was previously Professor of
Water Engineering and Head of the Department of Civil Engineering
at the University of Bradford. He graduated with a PhD from Imperial
College, London, in 1976. He manages a range of research contracts
on modelling flow (including flooding), water quality and sediment
transport processes in coastal, estuarine and river waters and has published over
300 papers and technical reports in the field. Roger is a Fellow of the Royal Academy
of Engineering and the City and Guilds Institute of London. He was awarded the
1999 Royal Academy of Engineering Silver Medal, the 1994 Institution of Civil
Engineers (ICE) Telford Premium and the 1991 International Association for
Hydraulic Research (IAHR) Ippen Award. His computer models have been used
extensively in over 100 Environmental Impact Assessment studies worldwide and he
has served as a member of council of several institutions, including the ICE, CIWEM
and IAHR.
Dr Douglas Parr
Dr Parr is the Chief Scientist and Director of Policy at Greenpeace UK,
looking after the science and political lobbying functions. His current
focus is on tackling climate change in the power, heat and transport
sectors. He joined Greenpeace 14 years ago, and has worked on a
number of technical and policy issues including GM crops and
agriculture, chemicals legislation, green refrigeration, biofuels and
nuclear power. He obtained a D.Phil in Atmospheric Chemistry in
1991.
Bob Taylor
Bob has been a Board Member of E.ON UK since 2001 and was
appointed Managing Director, Generation in July 2007. His Board
responsibilities include generation, energy related R&D and the longterm development of clean coal and nuclear generation options for
E.ON UK.
He gained a BSc (Hons) in Electrical and Electronic Engineering from
Manchester University (UMIST) in 1983. He then joined the electricity
industry and held a number of operational, engineering and commercial roles in the
UK and overseas with Powergen plc. Most recently he was Managing Director of
E.ON Central Networks (formerly East Midlands and Midlands Electricity
Distribution). Bob holds an MBA from Aston Business School and is a chartered
engineer and fellow of the IET. He is a Member of Council of the University of
Birmingham.
Yaver Abidi
Yaver is a civil engineer with 27 years of experience as a consulting
engineer in North America, UK, Asia, the Middle East and Africa. His
areas of specialisation are geotechnical engineering for hydroelectric
power projects. He is currently group development director for Halcrow
Group Ltd. He holds a MSc in Soil Mechanics from Imperial College
London and MS in Management from Stanford Business School.
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ACADEMY BRIEFING: THE SEVERN BARRAGE
Chair:
Dr Sue Ion OBE FREng
Keynote Address:
Malcolm Wicks MP, Minister of State for Energy
Panel:
Professor Roger Falconer FREng
Dr Douglas Parr
Bob Taylor
Yaver Abidi
INTRODUCTION
Dr Sue Ion: Ladies and gentlemen, a very warm welcome to you, here at the home
of the Institution of Mechanical Engineers. We are very grateful to the Mechanicals
for enabling us to host the event here today rather than at the home of the Royal
Academy of Engineering which is now at 3 Carlton House Terrace. The reason for
the move is that we cannot currently accommodate the number of people who are
interested in today’s event and the Institution of Mechanical Engineers very kindly
offered us their lecture hall to take the numbers, rather than disappoint anyone.
Programme
It gives me great pleasure to be here this afternoon. I am Vice President of the Royal
Academy of Engineering and Chair of our Engineering Policy Committee. One of the
things we have been very keen on over recent times is being able to input opinion on
challenging issues in the energy and environment arena. The title of today’s lecture
topic, the Severn Barrage, is of course right at the top of the issues in the energy and
environmental arena.
This afternoon’s meeting enables the Minister, Malcolm Wicks, to say a few words to
us. He had hoped to be with us for the whole of the afternoon but, as would happen
in the political arena, with the price of oil going through $140 per barrel this
afternoon, this means that he and his officials have to be available to make
comments to others. The Minister will stay with us for as long as he can.
We have with us Roger Falconer, Doug Parr, Bob Taylor and Yaver Abidi, to give us
seminal talks on the issue and then hopefully there will be a lively discussion which
will set the scene for what I am sure will be further debates, going forward.
The history and the debate
The History and the Debate
1849 - Thomas Fulljames
1925 - English Stones Study
1931 - Paul Shishkoff: Avonmouth Prototype
1933 - Severn Barrage Committee
1940s - Nazis plans for after invasion
1948 - Government Study
1953 - Government Study
1971 - Tom Shaw
1975 - CEGB
1981 - Severn Barrage Committee
1984 - Wimpey Atkins
1987 - Hooker Barrage
1989 - Severn Tidal Power Group
2006 - Gareth Woodham
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The topic in which we are interested today is not new. Back in 1849 there was a
proposal for a barrage from Beachley to Aust, which is now the site of the first Severn
Bridge, with a span of just over a mile. This was not with electricity generation in
mind but for railway transport and flood protection and, since then, there have been
many studies. There was the English Stones Study; a prototype by Paul Shishkoff;
the Severn Barrage Committee which recommended a barrage over the English
Stones area. There were studies by the Nazis, who planned to put one there after
they had invaded Britain. There have been two government studies. There is the
work by the tidal expert, Tom Shaw, and the CEGB’s serious look at the idea. There
is the Severn Barrage Committee, which became known as the Bondi Committee
after Professor Sir Hermann Bondi, and there are other studies coming forward
today.
The proposals for options for a Severn Barrage are now very much out for
consultation. So it is not new, and it is potentially a contributor to our safe and
secure and low carbon energy for the UK, going forward. I am sure that this
afternoon’s debate will help enormously in aiding the Government to reach some
conclusions later on.
Current Feasibility Study
The current feasibility study was announced in January 2008 and it is there to gather
evidence and assess high level evidence and to decide whether the Government
could and should support a tidal power scheme and, if that is the case, on what terms
that should be.
Today’s Severn Barrage meeting
For today’s meeting, we will be looking at the state of engineering and at
environmental balances – the balances between low carbon energy versus
environmental impact; how such a barrage would fit into a renewable energy
strategy; how it affects the rest of the electricity market; how to finance such a project
and, indeed, from the Royal Academy’s point of view, the engineering challenges
inherent in delivering such a project in the timescales that would be required.
The Severn Barrage
Without further ado, I would like to welcome Malcolm Wicks, our Minister of State for
Energy, who will give you the Government’s view, before we move on to the
presentations by our other speakers.
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KEYNOTE ADDRESS
Malcolm Wicks, MP: Sue, thank you very much indeed. Looking at this illustrious
audience, it answers that obvious question: how many engineers does it take to build
a tidal barrage? Who knows, it may take more.
I was asked in the House of Commons today by a Liberal Democrat if I could
estimate the price of a barrel of oil in the year 2020. I said to him that it is really
rather difficult to estimate what it might be tomorrow. This reminds us, of course, that
for parts of energy policy, Harold Wilson’s old saying that ‘a week is a long time in
politics’ still rings true. Interestingly enough, however, the discussions that we are
having today give the lie to the generalisations that you can make about a week
being a long time in politics. What we are about here, I guess, is discussing rather
seriously whether there might be a possibility of a Severn Barrage – constructed and
up and running – in 2020, 2021 or 2022, which is really quite a long time period. Of
course, our longer time period is even longer because it is about how humankind can
now start to reverse the trends in terms of carbon emissions and save the planet.
Our Government has set the target that, by the middle of this century, 2050, we
should be aiming – against where we were in 1990, so that it is quite a tough target –
to reduce our carbon emissions by 60 per cent. Indeed, Gordon Brown has more
than hinted that if the evidence warrants it, we may well increase that figure to 80 per
cent. We are therefore embarked on a course here in the UK, across Europe and
hopefully across the world, to start to take the carbon out of our economics and our
economy. Therefore, 50 years, or 30 or 20 years, is not a long time in climate
change politics. We need to look ahead and it is right and proper that we are looking
at the feasibility of this most ambitious project.
It is my pleasure to be here today to discuss with you the feasibility study on tidal
power in the Severn Estuary. May I thank the Academy for hosting this early
discussion of the issues. Your engineering expertise will obviously be invaluable to
the success of the study and I look forward to hearing your views during the period
for which I can stay here this afternoon and, of course, during the coming months
and indeed over the next two years. As you all know, this is a huge and historic
project and the feasibility study alone is an ambitious and necessarily relatively
lengthy exercise.
As we have just seen – and it is rather humbling to look at the history – proposals for
damming or barraging the Severn Estuary are nothing new. The most recent studies
in the 1980s looked at the potential for generating electricity by harnessing the
estuary’s huge tidal range which, at 14 metres, is secondly only worldwide, so I am
told, to the Bay of Fundy in Canada. The conclusion in 1989 was that a barrage was
technically feasible and that a barrage from Cardiff to Weston-super-Mare would
have an annual output of around 17TWh, which could supply up to perhaps 5% of
today’s UK electricity demand. This would allow an annual carbon dioxide saving of
over 6 million tonnes or about 1% of UK emissions today. However, the government
of the day decided that a barrage was not then a cost-effective option.
Of course, times have changed. The economics have changed and there is no
longer any serious debate about climate change and the need to act now to reduce
our carbon dioxide emissions is clear. At the same time, we must ensure that we
continue to enjoy reliable, safe and competitively priced energy supplies – no small
task at a time when prices in global energy markets are sky-rocketing, as I alluded to
at the beginning of my remarks, and when a large proportion of fossil fuel reserves is
in some of the less stable regions of our planet. These challenges require a diverse
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and increasingly low carbon mix that includes consideration of all reasonable options.
We are acting now as a government to move rapidly in just that direction: we are
acting on CO2.
Increased energy efficiency – we believe in nuclear power and we believe that
carbon capture and storage for fossil fuel plants all have vital roles to play going
forward, as to renewables. We are making rapid progress on offshore wind, as you
will be aware, but a potential flagship renewables project is of course this Severn
tidal power scheme – a barrage or perhaps a lagoon. This is why, when I led the
Energy Review, back in 2006, I asked the Sustainable Development Commission
(SDC) to look again at tidal power options in the Severn Estuary and we are of
course grateful for their insight and their advice. Their study, which looked at tidal
range and tidal stream technologies, reported in the autumn of last year and I was
pleased with the key message that tidal power can be generated in the Severn
estuary, within sustainable development principles and so it remains an option open
for consideration in the context of our developing renewable energy strategy, on
which we will be consulting this summer.
As the SDC, advised, much more work needs to be done before a decision can be
taken on whether to proceed with a tidal power scheme. For example, we need to
use up-to-date modelling techniques to assess and understand the potentiality and
considerable environmental impacts. We also need to consider the issue of
compensatory habitat and we obviously need to look at costs, financing and
ownership issues and also at the considerable regional, social, economic and energy
market impacts. This is a massive and extremely complex project and we must take
the time to gather a robust evidence base and ensure that all these impacts are truly
understood. We are doing this through our feasibility study.
The feasibility study, which will build on the work of the Sustainable Development
Commission and earlier studies, will run until 2010 and it will enable us to decide
whether and, if so, on what terms government could support a tidal range project or
projects in the estuary. The full terms of reference are available in your papers for
this meeting. The study will focus on tidal range technologies, including barrages
and lagoons because, as the SDC report highlighted, this is where the main resource
of the estuary lies.
The study will have two phases, with a decision point at the end of each. The first
phase is likely to run until late this year, 2008, will focus on high-level issues,
producing a short-list of potential tidal power project options. We will then reach an
initial view on whether there are any fundamental issues which mean that the project
cannot proceed and, at this point, later this year, there will be an internal decision to
either stop or to continue with our evidence gathering and assessments. If the
decision is taken to continue, we will then consult on our short-listed tidal power
options and the scope of the strategic environmental assessment, about which I shall
say a little more later, and begin phase 2, looking at the issues in greater detail and
narrowing down to a preferred tidal range scheme. This will culminate, should we
reach that point, in a full public consultation in early 2010.
The study is being carried out by a cross-government team led by my department
and including representatives of the Welsh Assembly Government and the South
West Regional Development Agency. The team are also taking external advice – we
want it to be inclusive, engaging interested stakeholders and the public. We are
keen to hear your thoughts on how we can best engage with you. We have asked
the RAEng to consider who might serve on an independent expert panel, to advise
the study on technical and engineering aspects and also to peer review outputs.
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I would just like to give you a little more detail on what we will be doing over the next
two years. The study has been split into six main areas of work as follows.
1.
Environmental work, gathering the evidence of the impacts on biodiversity
and wildlife, land and seascapes, flood management and geomorphology.
Actually, my note says in brackets, “that’s sediment to you”. I don’t know
whether they thought that esteemed engineers did not know what
geomorphology was, or whether they thought their Energy Minister was not
too sure. Can I say that, as a politician, I am frequently up to my neck in the
stuff, or worse, so that I am geomorphologically literate. Nevertheless, we are
looking at the geomorphology and we are looking at water quality and
considering compensatory habitat issues. That is a very important feature of
our environmental work. We will be looking at the issue of compensation and
mitigation with commitment and imagination, considering – as the SDC
suggested – whether there is an environmental opportunity in linking
environmental compensation measures to climate adaptation.
2.
The second stream of work is about engineering and technical aspects,
considering issues such as the cost, design and construction of the proposed
tidal power schemes and their potential impacts on the electricity network.
3.
The third stream of work is about economics, considering how a project or
scheme could be financed, and looking at ownership options. We will be
looking at the full range of possibilities, including the need for any government
support and we have appointed PricewaterhouseCoopers to provide advice
on those issues.
4.
Fourth, there are the regional impacts, looking at the regional, social and
economic impacts, including the impacts and benefits on local business.
5.
The fifth stream of work is about planning and considering regulatory
compliance issues, although this will come later in the process.
6.
Finally, and very importantly, throughout the project communications work
and engagement with interested parties and the public will be key to the
successful delivery of our study.
The study will also include a strategic environmental assessment, to ensure a
detailed understanding of the estuary’s environmental resource, recognising its
national, European and indeed international nature conservation significance. Earlier
this month we announced the appointment of a consortium led by consulting firm
Parsons Brinckerhoff, to manage the strategic environmental assessment. I am very
pleased to welcome the consortium, PB, to the show and to the team because they
have a strong engineering and environmental capability. I am confident that they will
help, along with your expertise, to develop the robust evidence base which we
certainly need.
One of the immediate tasks for the PB team will be to carry out a technical options
appraisal of the existing and new schemes in order to narrow them down to a shortlist of projects, or a combination of projects perhaps, on which we can base the
detailed environmental assessment and other study work next year. This work will
both refresh the designs from the 1980s and also work up the less-detailed proposals
as needed, looking particularly at updating cost projections and the issue of ebb/flow
generation and the trade-offs for generating electricity more evenly.
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To help inform this work, on 12 May the consortium issued a call for evidence which
was in two parts. First, there was a call for proposals, inviting evidence-based
proposals for technical and financial information, on proposals for the tidal range
power development in the estuary, including information on how previous proposals
have been further developed. Second, there has been a call for information, such as
information on environmental impacts, which could usefully contribute to the
evidence base for the initial appraisal of the scheme. The technical part of the call,
the call for proposals, closes on 13 June, while the information part will run until 11
July. The team will then be considering with stakeholders all the information
provided, before including the proposed short-listed options in the first consultation at
the end of this year, when we will also be consulting on the scope of the strategic
environmental assessment.
We want to bring in your expertise and we will be looking forward to doing so,
through workshops and expert panels. Please respond to the call for information and
evidence or contact the team if you would like to be more involved. Website
addresses and contact details for both my department, BERR, and Parsons
Brinckerhoff, are included in your papers.
Let me just add this point. I have been impressed by the way in which people have
received the possibility of a Severn Barrage and they have appreciated the way we
want to work with groups – not least on environmental assessment. I think that is
important because I sometimes feel in this country, and perhaps in other countries
too, that while everyone seems to be signed up now – and I think this is good – to the
science on climate change and the need for action, there is a willingness to will the
ends but not the means.
Many projects that come forward to tackle climate change, to reduce carbon
emissions – and I suppose that nuclear is the most controversial but it could be the
humble wind farm in a locality – are too often opposed by people almost as an
instinctive reaction. There is even hostility to the ideas around carbon capture and
storage when, moving forward in a world which will be burning fossil fuels, not least
in China, we need to develop that engineering and technology. I sometimes think
that people are so concerned about the short-term and the impact on a landscape or
a seascape that they forget that, unless the world acts on carbon emissions, much of
the birdlife and the species they wish to protect could well be extinct within the next
100 years.
We live in a time when government needs to take tough and difficult decisions –
sometimes controversial decisions – about how we tackle global warming, and get on
the right side of the argument about climate change. However, those tough and
difficult decisions are surely not only for government but they are also for citizens and
they are certainly for the environmental groups that have led the debate in this
country about these important issues.
In conclusion, we know that the Severn estuary has the potential to generate
significant proportions of the electricity that we need, from an indigenous, renewable
source – saving, as I said earlier, perhaps about one per cent of UK CO2 emissions.
We know that we must act now to meet the considerable challenges of climate
change and energy security. We also know that a Severn tidal power scheme could
have considerable environmental impacts and that is why we are doing more work to
ensure that we truly understand all the potential impacts before we take a decision
whether or not to go ahead.
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I hope everyone will keep an open mind, as the Government will, in developing the
right solutions to help meet the challenges of climate change and energy security. I
look forward to working with many of you as we take this project forward. Thank you
very much.
***
Sue Ion: Thank you very much indeed, Minister, for that very comprehensive runthrough of government intentions over the next few years. I am sure that people in
the audience will have been pleased to hear about the manner in which the
Government wishes to conduct the input leading to decisions on the options in the
energy sector generally and specifically about the Severn Barrage. You asked how
many engineers it would take to build one and all I can say is that, in one of the
presentations later on, you will hear that 44,600 workers will be required per year at
peak during the construction period, so this is a very significant endeavour in
engineering space, as well as in other space.
Let me now introduce Roger Falconer, the Halcrow Professor of Water Management
and Director of the Hydro-environmental Research Centre of the School of
Engineering at Cardiff University. Roger was previously Professor of Water
Engineering and Head of the Department of Civil Engineering at the University of
Bradford and he has a long-standing career in the sector with many awards. His
computer models have been used extensively in over 100 environmental impact
assessment studies and he has served as a member of council of several
institutions, including the Institute of Civil Engineers, the CIWEM and the IAHR.
Roger, I would like to invite you to give our seminal talk on the Severn Barrage.
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12
SEVERN BARRAGE PROPOSALS: PROBLEMS AND POSSIBLE SOLUTIONS
Professor Roger Falconer FREng: It is a pleasure to be here this afternoon. As
Sue kindly said, I am sponsored by Halcrow, the leading international consulting
engineering company in this field, and truly British.
Challenges and Opportunities
For some reason, the title of this presentation was changed at some stage. This was
probably my fault for not properly responding to an email, but it was changed to
‘Problems and Solutions’ and I would like to change it to ‘Challenges and
Opportunities’. We have to look at the challenges of this project and the
opportunities. No one has been better internationally than British engineers at
addressing challenges and British engineers have been second only to the Welsh
rugby team in taking opportunities.
The current challenge
First, I would like you to watch this video. [Short video shown: succession of different
views about effect of a Severn barrage]
[Referring to video] Three items on BBC news – all of them incorrect. First of all, we
were told that the bird population would be 23,000. We were not told that it would
halve, but it has actually halved in 10 years according to RSPB figures.
Secondly, we were told that the bore would go but that is not necessarily true.
Thirdly, the people in Upton-upon-Severn have had enough problems with flooding,
without being told at this stage, before the studies have even started and let alone
completed, that the flooding will be worse as a result of the barrage. I hope that you
will see later from our computer simulations that it is extremely unlikely that any
flooding would occur in the Upton-upon-Severn region as a result of the barrage.
This, to me, is one of the big challenges that we currently face: that of
misinformation.
General challenges
General Challenges
x Growing world-wide increase in demand for
energy - particularly in India and China
x Tidal energy generation has advantage over
wind and waves - tides are predictable
x UK target of generating t 20% of electricity
from renewable resources by 2020
x Wales’ 2025 target for marine renewables is
14 TWh/yr - Barrage could generate 65%
x Severn Estuary basin is ideal for tidal energy
4
What are the general challenges? We see here the growing worldwide increase in
demand for energy, particularly in India and China. I would just like to dwell briefly on
the point about China because I do not think we realise what the Chinese actually
want. One has the impression, when reading British newspapers, that the Chinese
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actually want to drive around in four-wheel drive Range Rover cars and so on.
However, I have been going to China since 1980 and I have been very fortunate to
visit the homes of Chinese people and stay with them.
I have been to Shanghai in the winter and lectured. The reality is that China has less
in terms of domestic heating than we had in this country at least 50 years ago –
where I was born in West Wales we had one fire in the living room and everyone sat
around that. In the living room in China, it is so cold in their homes that you open the
fridge to get warm. South of the Yangtze River, there is no heating in the homes, nor
hot water. You give lectures in Shanghai Jiao Tong university in the winter and you
are there wearing an overcoat and three jumpers and so are all the students. The
Chinese are becoming wealthier but they want to spend their money on things that
we took for granted 50 years ago, and we need to get that into perspective first.
We are talking today about tidal energy generation, which has many advantages over
wind and waves. It is predictable – we can predict it next year, the year after, and so
on. The UK target is to generate more than 20% of electricity from renewable
sources by 2020 and the Wales target is for that by 2025 14TWh will be produced
per annum from marine renewables, of which 65% could be produced from a
barrage, assuming that half the energy generated went to Wales and half went to
England.
To put that into perspective, the barrage would produce enough electricity generation
for the needs of the whole of Wales, 3 million people. The Severn estuary is an ideal
basin for tidal energy.
Planned renewable energy provision
Planned Renewable Energy Provision
Considerable
Scope to increase
EU target of 20% carbon reduction by 2020
5
This slide shows the planned renewable energy provision for the European Union by
2020. The very narrow line at the top shows the tidal and wave generation and it is
very small. This is the area in particular where there is tremendous scope to develop
the business in tidal and wave renewable energy.
Mean spring tidal range resource
When we look at a barrage, we are talking about tidal range provision of energy.
Here, you can see that there are two very attractive sites, one in the Bristol Channel
and the Severn Estuary and the other is along the North Wales coast and the
Morecombe Bay area.
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Severn Estuary
Looking at the Severn Estuary, we see the beautiful beaches on the Welsh Riviera
and some beaches on the English coast – not quite the same!
Proposed tidal devices for Severn Estuary
Turning to the more serious point, there are three proposals that are being
considered by many parties for energy provision in the Bristol Channel and the
Severn Estuary. One is the tidal stream turbines that will basically have the wind
turbines in the water column. There are tidal lagoons, referred to generally as
offshore tidal impoundments: here we build a wall offshore and basically it is the
same as the barrage. Then we have the barrage, which is an embankment across
the estuary.
Potential power from tides
Potential Power from Tides
x For tidal stream turbines:-
Power v V 3
V = mean free-stream tidal current
x For tidal barrages and impoundments:-
Power v A H 2
H = level difference across barrage / lagoon
A = wetted surface area upstream of barrage
9
If we look at the potential for power from tides, the power is proportional to the cube
of the velocity, so we want to locate the tidal stream turbines in areas of high velocity.
If we look at the barrage and the impoundments, then the power is proportional to
AH2, where H2 is the level difference between the inside and the outside of the
barrage or the impoundment. In particular, I would like to draw your attention to the
fact that the power is proportional to A, which is the planned surface area. If we want
to talk about lagoons, for example, then we need to have a very large area to have
the maximum possible energy provision.
EIA studies for all impoundments
EIA Studies for All Impoundments
x Computer models used to predict changes to:¾ Tidal currents – speed, levels, eddies, river plumes
¾ Wave climate – height, length, refraction, reflection
¾ Suspended sediment – distribution along channels
¾ Sediment deposition – in and out of impoundment
¾ Coastal morphology – changes to beach profiles
¾ Water quality – turbidity, bacteria, light penetration
¾ Pre-/post-construction – short & long term impacts
¾ Mitigating measures – changes to design/operation
10
15
Then, in all these studies, we would need to carry out environmental impact
assessment studies. I will not dwell on this but we would need to look at the tidal
currents and how the structure would affect the speed and water levels. Would
eddies be formed, and how would the river flumes be affected and so forth,
particularly if we were to build impoundments? How would the wave climate change,
and how would the wave heights change? What about the wave lengths, refraction,
diffraction and so on?
How would the suspended sediment distributions change along the main channels,
along the beaches and so on, and the sediment deposition? That will have a knockon effect on water quality, to which I shall allude later. In the coastal morphology,
how will the beach profiles change as a result of building an impoundment or a
barrage? How will the water quality change and how will the turbidity change? What
about bacteria, light penetration, nutrients, dissolved oxygen and so on?
Then, what will happen during the construction period? I shall come on to that very
briefly. In Cardiff Bay we saw considerable impact in the pre-construction stage and
the post-construction stage. Then what mitigating measures might we want to
implement before any structure is finally built?
Tidal turbines – Swanturbines
Tidal Turbines - SWANTURBINES
SWANTURBINES Concept
x Simple, robust, economic
x Environmental impact low
- slow blade velocity
x Diversification of existing
renewables technology
x Direct drive to generator
x Gravity base foundations
x Easily removed if needed
12
http://www.darvill.clara.net/altenerg/tidal.htm
This is an example of tidal stream turbines and this shows you the real benefit of
universities and companies working together. This was developed by Swansea
University and is called the Swanturbine Project. It has many advantages over
several competitors in that it is simple, robust and economic and it does not require a
gearing system – it is direct drive. When you look at a single turbine, such as the
one shown here, they have very little impact on the environment. Once again,
however, we have to get things into perspective. If you are going to equate like for
like – and we should not be doing that because we want to see the barrage
complementing tidal turbines and so forth – you would need 8,000 tidal turbines to
equate to a barrage. If you put 8,000 tidal stream turbines in the Bristol Channel,
which is not possible anyway, it would clearly have a knock-on effect on the aquatic
environment.
Tidal lagoons or impoundments
Before I talk about the barrage, let me say a little about tidal lagoons because I think
there is a misunderstanding on a number of issues with regard to these.
16
Tidal lagoon concept
Tidal Lagoon Concept
Source – University
of Colorado
14
The concept of a lagoon is similar to the sketch shown on the right hand side of this
slide. You build a wall offshore and you fill the two to high tide. You then hold the
water inside the lagoon and let the water level drop outside as the sea level falls from
high tide to low tide. Then, at low tide, you open the lagoon and the water all rushes
out and then you close the turbines again and allow the sea level outside to rise from
low tide to high tide and then, at high tide, you open the lagoons again. Thus, at low
tide and high tide, you have a large head and you generate a good deal of electricity.
Location of Swansea lagoon
Location of Swansea Lagoon
Source – Tidal
Electric Ltd
15
However, I do not think we always appreciate the size of these lagoons. This slide
shows the lagoon proposed off Swansea Bay and it looks quite small on this sketch.
The embankment wall of this lagoon is 9km long, which is 12 times the length of the
Cardiff Bay barrage. It corresponds to a planned surface area two and a half times
the size of Cardiff bay – and I am usually talking in Wales where people know the
size of Cardiff Bay. However, if you do not know the size of Cardiff Bay, it
corresponds to the size of 1000 football fields so it is a very large structure. The
mean tidal range is 8.5m and the energy output is 124 MWh pa and, if we equate like
for like, we would need 135 lagoons to give us the same power as the barrage. It is
costed at the moment at £240 million but I do not think any contractors have been
involved in the costings because the Cardiff Bay barrage, which is 700m long, cost
£200 million 10 years ago. This wall will be nine times as long, in deeper water, and
17
it will be the same price. Now, I am an academic and so I know nothing about costs
but it does not seem realistic to me.
Impact on currents and sediments
How will the current here be affected by such a massive structure in Swansea Bay,
and so on?
Will rapid siltration occur?
Will Rapid Siltation Occur?
Area of
deposition
Deposition
remains
OTI
Incoming Tide
Outgoing Tide
Phenomenon of tidal pumping
18
What about siltration? There are many technical issues with which we should be
concerned here but me just take one, if I may. When we teach fluid mechanics to
students in their final year, we often get onto the topic of tidal pumping. We have a
basin, circular in shape – it is an offshore tidal impoundment. We have an incoming
tide and we create a circulating flow and the sediment particles which will be brought
in, particularly in the Bristol Channel where you have high suspended sediment
levels, will be taken to the back by this relatively high momentum jet. On the
outgoing tide, the water flows to the sink and we have basically a potential flow and
the sediment is left at the back.
This happened indeed in Cardiff Bay when it was built, when they reduced the width
of the entrance of the bay from 700m. They took 200m off from the Penarth side to
construct the coffer dam to build the locks and so forth, and they had 200m reduced
on the dock side to get the concrete and so forth in to build the locks. So the bay
width was reduced from 700m to about 200m virtually overnight and, as expected, a
great deal of sediment silted up at the back of the bay. Unexpected? It would not
have been unexpected if they had done coastal engineering at Cardiff University.
Proposed pilot scheme for OTI
Proposed Pilot Scheme for OTI
Source – Stuart
Anderson
19
18
I have just taken one example but there are many others. If we are going to put
massive structures offshore, then we have to take account of the hydrodynamic flow
characteristics and so on.
This is a proposal of which I am much more supportive. It is a small offshore tidal
impoundment – these slides are courtesy of Stuart Anderson who is here today. The
idea here is to build a pilot study where we could look at some of these issues, such
as sedimentation. Basically, we would have a large laboratory for universities,
companies and so forth to look at.
Proximity to key estuaries
Proximity to Key Estuaries
Size for viability
12 km x 5 km
Per | 27 km
Source – Stuart Anderson
20
There is a proposal off the Rhyl coast to build an offshore tidal impoundment 12km
long by 5km wide, which is nearly 50km2, which is bigger than the plan surface area
of Cardiff. That wall is 27km long. It does not strike me to be very good to build a
wall 27km long, offshore, like that.
Coastally attached impoundments
Coastally Attached Impoundments
Wall length
Per | 28 km
x Generate power 4 hr out of phase with Severn
x Provide coastal flood defences for Towyn etc.
21
Source – Stuart Anderson
However, what is much more impressive is Stuart Anderson’s proposal that we
should put a lot of coastally attached impoundments here. That wall is the same
length as No. 3 here and the wall length is 28km. Towyn is a town which was badly
affected by flooding. A coastally attached impoundment would generate electricity
four hours out of phase with the Bristol Channel. I will not pursue this point, but we
19
have to look at energy generation with an holistic approach and not just through the
Severn Barrage and so on. We need to look at how we can integrate systems
together all around the UK. Here, you can see the coastally attached impoundment,
the same length as the previous structure and half of this wall is now in shallower
water and therefore cheaper to build. It also attaches to the coast and it has the
advantage of giving flood defence to Towyn. Thus, I think the coastally attached
impoundments are much more attractive in principle than the offshore tidal
impoundments because, in many cases, they give us the benefit of flood defence.
Severn Barrage
Let me turn to the topic that we are here to discuss today, which is the Severn
Barrage. As Sue mentioned, a barrage across the Severn was first proposed in 1849.
Severn Barrage proposed site
Severn Barrage Proposal Site
Some key facts:
x 2nd highest spring
tidal range | 14 m
x Cardiff to Weston
x Length about 16 km
x Generate | 5% of
U.K. electricity
x Total cost | £15 bn
x Private funded - by
Severn Tidal Power
Group (STPG)
Slides - courtesy of
STPG / David Kerr
24
I shall be talking about the Cardiff Western barrage because that is the one that most
people think about when we talk about the Severn Barrage. It has the second
highest rise and fall of tide in the world. From Cardiff to Weston, the length is 14km,
generating 5% of UK electricity, with costs of about £15 billion. This proposal is the
one from the Severn Tidal Power Group.
Barrage layout (1989 report)
Barrage Layout (1989 Report)
Key facts:
x 216 turbines
each 40 MW
| 17 TWh/yr
x 166 sluices
x Ship locks
x Fish passes
included
x Public road?
25
20
There would be 216 turbines, each generating 40MW, 17TWh/year, with 166 sluices,
ship locks and fish passes and it is debatable whether there would be a road on top.
Construction – prefab concrete
Construction would be in precast concrete caissons, so that it would be rather like
Lego and built in deep water ports and transported into the area and then linked
together.
Proven technology – La Rance
In terms of the civil engineering aspects, in one sense there is nothing particularly
challenging about the project. We are basically talking about a low head dam and we
are talking about turbines which have been in place for 35 or nearly 40 years in La
Rance. I do not want to get onto the La Rance project, because that is very different
from the Severn for a whole host of reasons. However, it would not be the first
barrage because engineers have built barrages before and this one, in particular, is
widely known. It is very different for a number of reasons, particularly on the
environmental side.
Tidal power generation
Tidal Power Generation
• Barrage impounds tide, then water is released
through a turbine to generate electricity
28
The proposal at the moment is that the power will be generated on the flood ebb tide
only, so that the barrage impounds water on the incoming tide. The water is then
held for typically three hours and then released on ebb tide to generate electricity.
Proposed operation – ebb generation
Proposed Operation - Ebb Generation
29
21
The current tidal curve in the estuary upstream of the barrage is shown on this slide
by the blue line. If the barrage is built and operated in ebb tide generation mode,
then the red line shows the tidal curve that would occur upstream of the barrage.
Here, you can see the tidal range is reduced from 14m to 7m under spring tide
conditions.
Existing estuarine environment
The existing estuarine environment – let us put things into context. The current tidal
range in the estuary is 14m on spring tides and 7m on neap tides. There are very
high tidal currents in this area and there are very large inter-tidal zones. There are
30 million tonnes of suspended sediments on sprint tides and 4 million tonnes on
neap tides, so there are very, very high levels of suspended sediments. There is little
sunlight penetration through the water column and there are reduced saturation
levels in terms of dissolved oxygen.
If we turn to the ecology, it is a very harsh estuarine regime, particularly with the high
currents and the high suspended sediments. There is limited aquatic life on the
wetted seabed and the bird numbers are relatively small per square kilometre,
compared to most other UK estuaries. That is not to say that these points are not
important, however.
Changing natural environment
If we look at the current change in climate first, before we look at the Severn Barrage,
the temperature is rising. This will affect the ecology for birds, and so on. The sea
level will rise, to give increased flood risk: at the moment, we are expecting I to 2
metres over the next century, with some suggesting up to 5 metres. The water
quality is becoming cleaner all the time. We have the EU Water Framework Directive
and major investments by the water companies, so that discharges into the estuary
are cleaner all the time.
We have the Defra Catchment Farm Management initiative so that we are managing
the diffuse source pollution better all the time. Then, when one looks at the
legislation, should we look at the project under conditions now, or should we think
about 120 years from now, when a barrage may still be in place if it is constructed?
Bird species in SPA citation
Bird Species in SPA Citation
Citation category
Species numbers
between 1988 - 93
Species numbers
between 2000 – 05
(Red - Less, Blue - More)
Internationally important
populations of Annex 1
species
Bewick’s Swan - 289
Bewick’s Swan - 276
Internationally important
populations of migratory
birds
Shelduck - 2,892
Dunlin - 41,683
Redshank - 2,013
European Goose - 3002
Shelduck - 3,272
Dunlin - 23,312
Redshank - 2,566
European Goose - 942
Wigeon - 3,977
Pochard - 1,686
Ringed Plover - 227
Curlew - 3,096
Whimbrel - 246
Spotted Redshank - 3
Wigeon - 8,062
Pochard - 880
Ringed Plover - 665
Curlew - 2,545
Whimbrel - 222
Spotted Redshank - 10
Nationally important bird
populations
Source - RSPB
32
22
Let us look first at the RSPB bird figures, and at dunlin, which was cited in that TV
cutting. Dunlin have dropped since 1988/1993 from 41,000 to 23,312. So, in terms
of the bird population, a great deal is already happening in this estuary.
Estimated habitat changes
Estimated Habitat Changes
(Resulting from Climate Change)
Total estuary change
(compared to 2005)
Estimated area
(ha) for 2005
20 year
% change
50 year
% change
100 year
% change
Intertidal area
22,500
-7
-7
-11
Intertidal mudflat and
saltflat
20,000
-6
-5
-9
Saltmarsh
1,600
-13
-41
-38
Transitional
grassland
1,600
+13
+6
+6
Subtidal
46,000
+3
+3
+5
Source - SDC
33
There is much talk, once again, about the loss of inter-tidal habitat. This will be huge
and we all accept that it is of major concern. However, that is also reducing as a
result of climate change – albeit, not to the same extent as the bird reductions but it
is nevertheless changing.
Main effects of barrage
Main Effects of Barrage
x Spring tide range reduced from 14 m to 7 m
¾ Significant loss of upstream inter-tidal habitats
¾ Reduced tidal currents upstream of barrage
¾ Reduced suspended sediment levels upstream
¾ Increased light penetration in water column
¾ Increased dissolved oxygen concentrations
¾ Increased primary productivity and changed
and changed bio-diversity of benthic fauna
x Upstream tidal range of 7m is comparable to
other UK estuaries, e.g. Thames & Humber
34
What would be the main effects of a barrage? On the spring tide, as you saw from
the picture, the tidal range would be reduced from 14m to 7m. Without doubt, if we
operate in that mode, there would be a significant loss of the upstream inter-tidal
habitats and nobody disputes that.
There would be reduced tidal currents – the tidal range is much less. There would be
reduced suspended sediment levels and there would be increased light penetration
because there would be less sediment in the water column. There would be
increased dissolved oxygen in the water column. There would be increased primary
productivity and a changed biodiversity on the bed of the estuary.
23
We must not forget that the Severn Barrage is often compared to the Cardiff Bay
project, but the latter is quite different. We have impounded two rivers and we have
no change in the water levels upstream of the barrage. We will still have, if the
barrage is built here, as proposed, a tidal range of 7m, which is bigger than that of
the Thames or the Humber. So this will not be a stagnant pond of water.
Two-way generation?
If we really have so many major problems on the environmental side, as engineers
we can still address these by looking at the possibility of two-way generation and not
just locking ourselves into ebb tide generation.
Proposed: one-way generation
Proposed: One Way Generation
Option 1: Generate over ebb tide only
Level of water inside
impoundment
36
The current proposal is to operate the barrage in the mode shown on this slide,
where the blue line is the wave outside of the barrage or the seaward side, and the
yellow line indicates the shape of the curve in a simplistic manner, upstream of the
barrage. That is the one-way ebb generation.
Alternative: two-way generation
Alternative: Two Way Generation
Option 2: Generate and pump over full tide
Level of water inside
impoundment
37
If we go to two-way generation and we pump where you can see the red circles on
this slide, under low head at high tide and at low tide, then we can move the wave by
90 degrees out of phase.
24
Analysis for tidal impoundment
Analysis for Tidal Impoundment
x Calculations by Prof Jim Poole, EA Wales
x Maximum energy converted per tidal cycle
(J/m2), excluding losses, gives:Mode of generation
Energy
generated
Option 1 (Ebb tide only)
2,930 T
2
Option 2 (Flood and ebb
with pumping)
6,930 T
2
(T = Tidal Range)
x However, filling barrage impoundment with plan area
about | 500 km2 more complex than filling a lagoon
38
We keep the tidal range, and these are calculations done by my friend who should be
here today, James Poole from the Environment Agency – and nobody ever questions
anything from the Environment Agency. You can see here that James’s figures show
that in fact we can produce a great deal more energy as well if we have two-way
generation. I should say that those calculations were done for the lagoon, which is
clearly much smaller and they obviously need to be refined quite considerably for the
barrage. Nevertheless, those calculations would indicate that perhaps we can
generate as much electricity with two-way generation and also address some of the
environmental problems. In fact, the only problem we are left with then is that of fish
migration. However, as shown on this slide, filling a large impoundment of 500 km2
is more complex than filling a lagoon.
Alternative operating regimes
Perhaps two-way operation is something we should look at in greater detail. It would
reduce many of the environmental concerns. Two-way ebb and flood generation
would have several advantages. It would generate electricity over a longer period of
the tide and it would maintain the near existing tidal regime. It would generate limited
significant changes to the inter-tidal habitats and sluice gates may not even be
needed, which would allow us to put more barrages into the structure. Fish
migration, however, still remains a problem.
Model studies
We have been doing research funded by the Welsh Assembly government and I
would now like to show you some of the results from our computer model
simulations.
25
Severn Estuary hydraulic model
Severn Estuary Hydraulic Model
41
We have recently had a small physical model built. It is too small to make
engineering decisions on the barrage but it is ideal for our research students and
undergraduate students to work on issues relating to the Severn Estuary. It is a
1:25,000 physical model, in our hydraulics laboratory, and it was opened last week
by the Jane Davidson, Minister for the Environment for Wales.
Model grid configuration
Model Grid Configuration
Cardiff
Inner Barrage
42
This is our computer model, set up for the Severn Estuary. It goes from the outer
estuary right up almost to Gloucester. This is a finite volume, two-dimensional
model, for those who are interested, but I will not dwell on the modelling.
Validation of field data
W a te r L e v e l(m )
7
6
5
4
3
2
1
0
-1
-2
-3
-4
-5
-6
7
6
5
4
3
2
1
0
-1
-2
-3
-4
-5
-6
W a te r Le v e l(m )
W a te r L e v e l(m )
W a te r L e v el(m )
Validation of Tidal Elevations
7
6
5
4
3
2
1
0
-1
-2
-3
-4
-5
-6
7
6
5
4
3
2
1
0
-1
-2
-3
-4
-5
-6
(a) Avonmouth
Observed
Cal.
48
72
96
120
144
168
192
216
240
(b) Newport
Observed
Cal.
48
72
96
120
144
Time(h)
48
72
96
120
144
168
192
216
240
168
192
216
240
Time(h)
(C) Mumbles
Observed
Cal.
168
192
216
240
Time(h)
(d) Hinkley Point
Observed
Cal.
48
72
96
120
144
Time(h)
43
26
You can see here that the model produces perfect comparisons with the field data
and virtually perfect comparisons with the velocity field. This is exactly what a
consulting engineering company would want.
Validation of tidal current speeds
Validation of Tidal Current Speeds
2.4
2.4
Site F (51°21.5' N, 4°19.4' W)
Site M (51°20.1' N, 3°50.3' W)
2.0
Cal.
Obs.
1.6
Speed (m/s)
Speed (m/s)
2.0
1.2
0.8
Cal.
Obs.
1.6
1.2
0.8
0.4
0.4
0.0
0.0
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
-6
-5
-4
Time referred to HW at Avonmouth(h)
-2
-1
0
1
2
3
4
5
6
4
5
6
2.4
Site R (51°14.2' N, 3°21.1' W)
2.0
Site V (51°19.6' N, 3°04.8' W)
2.0
Cal.
Obs.
1.6
Speed (m/s)
Speed (m/s)
-3
Time referred to HW at Avonmouth(h)
2.4
1.2
0.8
Cal.
Obs.
1.6
1.2
0.8
0.4
0.4
0.0
0.0
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
-6
-5
Time referred to HW at Avonmouth(h)
-4
-3
-2
-1
0
1
2
3
Time referred to HW at Avonmouth(h)
44
This is the last thing on earth that an academic like me would want because how can
I persuade anybody to fund research at Cardiff University when the model is
producing good results? The very thing I want is actually poor agreement between
the model and the results, so that I can say, ‘Can you fund some more research?’
Turning to the more serious issues, you can see here that the model is predicting
currents quite well.
Grid resolution
We have a fine grid resolution around the proposed barrage site.
Velocity field around barrage
(a)
Velocity Field Around Barrage
Flood
2 m/s
water level(m)
2
2.5
3
3.5
4
Ebb
2 m/s
water level(m)
-4
-3
-2
-1
0
1
2
3
46
This slide shows computer model predictions of the flood tide through the sluice
gates in the top picture. In the bottom picture, you can see the tidal current from the
ebb tide through the turbines. The colours there represent particular magnitudes.
27
Tidal evaluations
I would like to show you some comparisons of computer model predictions. The one
on the left in each case shows you the situation without the barrage, while on the one
on the right is with the barrage.
Tidal elevations
Tidal Elevations
Lower high
water levels
Without Barrage
With Barrage
High Water - Spring Tide
47
This one shows you the tidal elevations at high tide. High tide refers to the site at
Barry, although it does not really matter where Barry is – it is just west of Cardiff. It
does not really matter, because they are all to the same high tide level in these plots.
You can see here that the levels upstream of the barrage are reduced at high tide at
Barry, and we have lower water levels both downstream and upstream of the
barrage.
Maximum tidal currents
Maximum Tidal Currents
Barrage reduces scope for
tidal stream turbines
Without Barrage
With Barrage
48
If we look at the maximum tidal currents, without the barrage on the left and with the
barrage on the right [on slide], you can see that the currents are reduced
considerably. There is no doubt that there is an important point here. If we build the
barrage we will reduce the currents in that area shaded in red, and that is one of the
very few attractive sites because the Bristol Channel is not suitable for tidal stream
turbines, for a number of reasons. However, I will not go down that route because
we are here to discuss the barrage today. So that is one of the most attractive sites
for tidal stream turbines.
28
There is no doubt that, if we were to go ahead with the barrage, that site is no longer
attractive for tidal stream turbines because the currents would be too low.
High suspended sediment levels
High Suspended Sediment Levels
Dynamic region of
high turbidity
49
This is the problem in the Bristol Channel. If you go over the Severn Bridge, the
water always seems dirty and muddy. This region is an area of very high currents. It
is very dynamic and it has very high turbidity levels and very high levels of
suspended sediment in the water column. It looks dirty.
Suspended sediment levels
Suspended Sediment Levels
Mean Flood
Reduced sediment
levels ¾ clearer water
Without Barrage
With Barrage
Mean Flood - Spring Tide
50
If you look at the suspended sediment levels on the left, this is a computer model
prediction and you can see very high levels here. The green shows you 800mg/l,
which is very high. You have to go to some of the biggest rivers in China to get
figures that are very much higher than that. These are very high, by international
standards, and that is why the water is brown. This is not mud coming down the river
but it is mud kept in suspension by the very dynamic currents.
On the right, if the barrage is built, you can see that the suspended sediment levels
drop off dramatically and that whole region would be much clearer.
29
Sediment bacteria transport
Sediment Bacteria Transport
water column
Wastewater outfalls
Catchment runoff
Water birds
Enteric
bacteria
Transported and
diffused by current
Sediment re-suspension
input
output
Overall reduction
Decay
Deposition
51
Then the sediment interacts with the bacteria, so we have bacteria coming down the
river. One might wonder what is the importance of sediment: sediment is much more
important than just dredging and navigational problems because it also affects water
quality. We have bacteria in the water column and this comes from waste water
outfalls, catchment run-off – diffuse source pollution, basically. The sheep leave it on
the land, you and I manage ours well. The sheep produce ten times as much fecal
coliform waste as you and I every day and it is left on the fields for weeks and then,
when a big storm comes, it is carried down into the river and then we have massive
fecal coliform loads in our rivers. This ends up in the estuary, and so on.
That input is then transported through the water column and diffused by the currents.
There is an overall reduction in the bacteria levels in the water column by the natural
process of decay and deposition of the bacteria on the beds. So the bacteria comes
down the river and latches on to sediments by chemical absorption and then it goes
onto the bed with the sediments. We then have a big storm and the sediments go
back up into re-suspension – this is what happens in the estuary – and we then have
fairly high levels of bacteria once again.
Riverine and WwTW Sources
Riverine and WwTW Sources
Rivers
WwTWs
52
We have done a comprehensive study here with the University of Wales at
Aberystwyth. We have put all these sources from the rivers and the waste water
treatment works into our model.
30
Bacteria levels
Bacteria Levels
Mean Ebb
Reduction in
bacteria levels
Without Barrage
With Barrage
Mean Ebb - Rivers in Flood
53
Here, you can see how the bacteria levels would change and drop, if we were to
build the barrage. The sediment transport is dropped and, if the sediment transport
level in the water column is dropped then the bacteria levels will drop.
Areas at risk from flooding
Areas at Risk from Flooding
x Barrage could be
operated to reduce
flood risk upstream
Gloucester
Cardiff
Bristol
x Flood risk seawards
likely to be slightly
less due to reduced
estuary length
x Flood risk due to
surges will be less
upstream
54
Many areas in the Severn Estuary are currently at risk from flooding and a great deal
of money is spent on flood defence in the area. The barrage could be operated to
reduce flood risk anyway. The flood risk seawards is likely to be slightly less, due to
reduced estuary length. If you go back to basic estuarine resonance, we would
expect it to be reduced slightly. The flood risk due to surges would be less anyway,
because the structure would stop the surges going further upstream.
Maximum water levels
Maximum Water Levels
Reduced
flood risk
Without Barrage
With Barrage
Spring Tide
55
31
If we look at the maximum water levels, the picture I showed you before of the tidal
water levels was the high tide level predicted at Barry and then the corresponding
water level everywhere. In this plot, I am now showing you the very maximum water
level predicted at any point for an extreme spring tide. Here you can see that, in the
whole of this reach, the water level is reduced. It is reduced by typically 1m
upstream of the barrage, which is consistent with the computer model predictions
back in the early 1980 studies. Not only is it reduced upstream of the barrage but it
is also reduced slightly, typically 10cm – 15cm, downstream of the barrage. So,
contrary to what the expert at the end of the Inside Out programme told you, there is
no evidence on the basis of our computer modelling that the area would flood at all
as a result of the barrage. In fact, the barrage would provide some reduced flood risk
management, both upstream and downstream – so I do not agree with the person
who spoke at the end of the BBC programme that I showed you.
Alternative Shoots Barrage
Alternative Shoots Barrage
Some Key facts:
x Energy yield |
2.75 TWh/yr
Severn Bridge
x Construction
period | 4 yr
Second Severn
Crossing M4
x Length | 4 km
x Less plan area
Shoots Barrage
x Slightly higher
tidal ranges
56
I will not spend any time on this project but there are a number of other proposals.
There is the alternative Shoots Barrage, about which many of you might have heard.
This is much shorter and it follows the route of the second Severn crossing. It could
be built in four years and its length would be only 4km, vis à vis the 16km for the
Cardiff-Weston barrage. The tidal range is slightly higher here. For those of you who
are interested in this, there is a good deal that can be picked up from the web but I
thought it better to concentrate on the Cardiff-Weston barrage in this presentation.
Many of the points I have raised about that are generic and would equally apply to
the Shoots barrage.
Concluding remarks
Concluding Remarks
x Tidal stream turbines attractive - limited EI
x OTIs require detailed EIA and cost studies
x CAIs offer opportunities for flood defence
x Severn Barrage would provide substantial
supply of tidal renewable energy:¾ Will be detrimental to several aspects of existing
environment ¾ but also some positive benefits
¾ Two-way Barrage operation and phased upstream
tide would address many environmental issues
¾ Barrage should complement other schemes
57
32
Tidal stream turbines are attractive and they have limited environmental impact.
Offshore tidal impoundments, in my view, will require detailed environmental impact
assessment and, in particular, detailed and serious costs studies. However,
coastally attached impoundments in my view offer us much greater value for money
and they offer much better opportunities for the future – particularly with regard to
being used in terms of flood defence.
The Severn Barrage would provide a substantial supply of tidal renewable energy. It
will be detrimental to several aspects of the existing environment and there is no
question about that. However, as you have seen from some of the computer
simulations that I have shown, there will be a great some positive benefits as well.
There would be the benefit of reduced flood risk, based on our computer model
predictions.
In my view, two-way barrage operation is something that we should look at, and
phasing the tide upstream. If we phased the tide upstream, we would be able to
generate electricity over a longer period of the tide and we would reduce some of the
environmental concerns that have already been raised. Finally, we should not see
the barrage as ‘the barrage or nothing’, but we should see it in complementarity of a
whole range of projects – tidal stream turbines, closely attached impoundments off
the North Wales coast and so on – so that they all complement one another rather
than competing.
The challenge
There is a considerable challenge for engineers to deliver the UK’s renewable energy
within a sustainable environment. The opportunity is there for the UK to lead the
world in renewable energy provision and to consider the environmental impact
issues.
Addendum
We need to have a vision to address climate change, and we can turn to the Bible for
the answer to that. Thank you.
Addendum
“Where there is no vision,
the people shall perish”
perish”
Proverbs 29:18
60
***
Sue Ion: Thank you very much indeed, Roger, for that absolute tour de force. There
will be the opportunity to address questions to Roger and the other speakers during
the discussion later in the afternoon.
Our next speaker is Doug Parr, Chief Scientist and Director of Policy at Greenpeace
UK where he looks after the science and political lobbying functions. He has been
with Greenpeace for over 14 years and has worked on a number of technical and
policy issues. He is well known in the energy sector for his commentary. Doug will
talk to us about a good low carbon generating option.
33
34
SEVERN BARRAGE – A GOOD LOW CARBON GENERATION OPTION?
Dr Doug Parr: Thank you very much, Sue. I am afraid I have no pretty pictures –
where Roger had 61 slides, I have three, and this is one of them.
As Sue said, I have been at Greenpeace rather longer than is probably good for my
long-term sustainable health but I have been involved in a variety of issues
concerned particularly with energy and increasingly on climate change, because of
the incredible potential threat and indeed actual threat that climate change now
poses. That will be the substance of my talk because the barrage throws up some
conundrums which I will explore with you today.
Just so that you know right upfront, do we have a position for or against the barrage?
No. It is probably too early to say, because there are some quite knotty conundrums
which we should not ignore. This is thus not a black and white issue. The first thing I
should say is that we are of course big supporters of renewable energy technologies
and that includes tidal range technologies, of which the barrage is potentially one.
We certainly have no in-principle opposition to this and we could even support it, and
I hope to explore the whys and wherefores with you.
Considerations
Considerations
•
•
•
•
•
Climate Change
Energy Policy context
Renewable Energy
Long-term future of energy system
Location & environmental impacts – the
international dimension
• Support mechanisms?
Here is a motley bunch of considerations that we bring to the issue of the barrage. I
would like to start by looking at the big picture because it is when you come from the
big picture down to this particular project that those conundrums become real.
Climate change
We start, of course, with climate change, which has already been discussed. We
believe that it is the biggest environmental threat, as I suspect most of you would
agree, and that it threatens human civilisation in the not-too-distant future. Because
of the variety of challenges that it will pose if we go above roughly 2 – 2.5ºC, then we
might find the melting of the Greenland ice sheet, which would involve a whole series
of changes – including the fact that we could not be in this room for much longer.
Over what timescale that would take place, however, is a very open question. Are
we talking millennia, or centuries or decades? Nobody really knows. However, that
is just one example of the many potential changes that climate change could bring
about and we tend to talk about these impacts simply as though they are in the
physical world.
35
Of course, if there are changes in the physical world then there are potentially
dramatic changes in the social, political and economic world if we create huge
numbers of migrants. If there are migrants in Bangladesh, where nearby there are
nuclear powers and we know about the political instability that migration causes.
That is an apocalyptic scenario but it exposes the sort of uncertainty associated with
the impacts of climate change and what that might mean. I am not using that to
scare but just to show that we do not really understand the full consequences.
Therefore, tackling climate change has to be an absolutely essential part of what we,
as a developed nation – particularly one where the industrial revolution took place –
have to do.
This means that we potentially need to make some sacrifices to make it happen. At
one level, does this mean that everything that we can do to stop climate change must
be done? That is not quite so straightforward though, is it, because that would mean
you would all be walking home, and that is not going to happen – it is not sustainable.
So how do we choose what things we do in order to tackle climate change? The
barrage is something that throws those challenges into particularly sharp context.
Malcolm referred to the emissions cuts that will be legally mandated in the Climate
Change Bill and it is no secret that there is a significant chance that they will be
increased. The other point to bear in mind is the considerable challenges that the
world and indeed the UK face in controlling diffuse sources of non-carbon dioxide
gases, which means that our energy system – if we follow something like 80% cuts in
carbon dioxide – will have to be pretty close to zero carbon by 2050. Therefore,
many options for low carbon generation need to be given careful consideration.
Energy policy context
We believe that the context for this is that we should be heading for a different kind of
energy system and a different kind of vision. We recognise that there are contexts
other than simply climate change, including energy security and how much of our
GDP we can put towards solving the climate issue. It is fair to say that I would
disagree with Malcolm on perhaps how much there should be but not that there
should be a limit and that you cannot dedicate everything towards solving climate
change at this point in time.
There is no question in my mind that, technologically – and you are all engineers and
you know this – there are all sorts of options we could have which would deliver us a
much lower carbon society. The reason that principally stands between ‘us’ and
‘them’ is that of cost. We are perfectly capable of producing and storing hydrogen on
the back of intermittent renewable generation and so if we just get enough of it, then
we can run our entire economies from that. Will that happen tomorrow? No, of
course not, because there are issues of costs and of practicality that will get in the
way.
How should we decide what to prioritise? This all seems rather ethereal but you can
realise that this kind of thing applies in spades when you come to talk about specific
projects like the barrage.
Renewable energy
We are big supporters of renewable energy and there are now renewable energy
targets. There is a 20% renewable energy target across the EU, which will translate
into something around a 15% target for renewable energy for the UK. We will have
to up our game considerably in order to meet that from our current level of something
36
slightly under 2% of renewable energy, so that means very large growth there. This
means that we will have to explore many options in order to get there. Sometimes,
for perfectly understandable reasons, the idea that the UK would need to produce
15% of its energy from renewable sources leads to rather a sharp intake of breath
and people think it will be hard. Well, yes, it will be hard but, when I say that that is
15% of renewable energy – leaving nuclear aside for a moment, 15% of our energy
will be renewable and so we will have to do something like quadruple that by 2050 in
order to come anywhere close to meeting these emissions reductions targets we
need to achieve.
Fifteen per cent for the UK is a big challenge but is it anywhere near enough? No, it
is the first stage. That is why options like the barrage cannot a priori be ruled out,
simply because they have environmental impacts – which it will, and quite significant
ones. As a starting point, however, we cannot rule that out. There are reasons why
it may not be the best option and I will come to those but, a priori, I would not rule out
the use of tidal range in the Severn and particularly with the barrage, simply on the
grounds that there are environmental impacts. Frankly, all energy sources have
environmental impacts. Wind farms kill birds but does that mean that we do not
support them? No, because we think they are needed, but one has to be mindful of
the balance between the over-riding need to deliver emissions reductions and the
size and scale of environmental impact that we are dealing with.
Long-term future of energy system
We have a long-term view about where our energy system should be going. One of
the critical factors as always is that, whenever you start to contextualise any
particular project or piece of work on energy, you always come back to energy
efficiency extremely rapidly because we cannot just keep producing more and more
energy to get to where we want to be. We are obviously big supporters of energy
efficiency and we could spend ages talking about that. We are also big supporters of
decentralised energy, where if we are using fossil fuels or even some of the
renewable fuels like biomass, we need to capture all the heat.
We need to use every bit of renewable energy we can possibly get – we need to use
every bit of energy that we can get from fossil fuels if we are to come anywhere close
to the kinds of emissions reductions that we need to make. Renewable energy,
including big scale renewable energy, will have to be part of this bigger energy
system, not just about power but also about heat. We need to integrate those two
systems together. I am talking here a good deal about electricity, because that is
obviously where the Severn Barrage sits in all of this.
Location and environmental impacts – the international dimension
Let me turn to some other observations. There are mixes of issues about where this
potential barrage might be and what the environmental impacts could be.
What are the biodiversity impacts of the barrage? At this point, I have to take a short
break and explain some of the nuances of ecological politics. Greenpeace is not an
expert on UK biodiversity – and I certainly am not. If you want to hear a detailed
description of the Severn’s biodiversity, the potential impacts and the reasons for
that, you are looking at the wrong person. There may well be someone who can give
us that information in the auditorium today, but it is not me. I therefore have to give
an assessment of this environmental impact in the broad brushstrokes that ignorance
allows.
37
In terms of important international habitats, whilst Latin America does broad,
aesthetically pleasing rainforests, in Britain we do mud. Some of the most important
habitats of international significance that we have in the UK are the mudflats. This is
not surprising in some ways because we are a coastal island with waves coming in
and out. We have plenty of coastline and we are a temperate western margin island.
For some species, we are a terribly important place because of these mudflats. The
Severn, because of its large tidal range, has a lot of mud.
It is certainly true that the wading birds on the Severn have led to the designations of
international importance on the Severn. Those birds, probably because climate
change is in fact already starting to impact, are not coming all the way over here from
their breeding grounds in Russia – they are staying on the east coast, because it is
warmer over there now and they do not have to come all the way. That is great – if
you do not have to fly across Britain, why would you?
Equally, the argument explored in the Sustainable Development Commission report,
which many of you may know, is that because it is a habitat of significance with the
very large tidal range that is involved, the physical foundations of that ecosystem will
remain unusual and therefore important in the future. Those things should not be
cast away on the basis of potentially short-term changes in response to climate
change, because the physical foundations of that ecosystem will remain. It is true
that it might not be as biodiverse as some other parts of the UK but, by analogy,
would we argue that, because the Arctic tundra and boreal forest is not very
biodiverse, then they are of no significance and it is good that they are warming up
and will become more biodiverse? I do not think we would.
In broad brushstrokes, changing an important international habitat of that kind is not
necessarily a good thing. Those are value judgments, about the value of ecosystems
in their current form, compared to the changes that might take place. We should be
explicit that those are value judgments. We can do a great deal of clever science
that might elucidate precisely what the biodiversity changes are and whether we
have more or fewer fish, or more or fewer birds, but I am not sure that that gets to the
route of it. In some ways, it is a question of whether we value those ecosystems in
their current state.
Because those ecosystems are potentially of international significance, it is not
somewhere you would want to change unless you had to. Whether we absolutely
have to do that is an extremely interesting question, the answer to which I do not
think we fully know. However, that is not really the place you would want to start if
you were trying to drive your energy system towards very dramatic increases in
renewable energy. Equally, as far as I am concerned, it is not something that you
would ever want finally to rule out.
Another point that I would raise here is that, in various shapes or forms – and there is
a process through the International Climate Change Talks taking place here – we are
essentially trying to tell a lot of developing countries not to trash their rainforests and
important ecological habitats in order to further their economic growth. That, in a
way, is what we would be doing to our own – we would be trashing our own important
ecological habitats, at least if you take the value judgments to which I referred earlier.
Is this something we can and should do? Discuss.
Further, my colleagues who follow the Framework Convention on Climate Change
more closely assure me that the UK influence on those talks needs to be backed up
by domestic action. ‘Do as I say, not do as I do’, is the sense that you sometimes get
from other countries about where the UK is coming from. Behaving and doing things
38
in the right way is quite important for our credibility and influence over those
international negotiations.
Support mechanism?
We then come on to the question of costs. As a scientist, this takes me well outside
my comfort zone, but let me explore this. A barrage, at the cost of £15 billion: the
SDC report makes it pretty clear – and I know that this is something that Sarah and
her team are exploring in depth in BERR – what should there be, and if so in what
form should any public support be for this project, a barrage type project or a tidal
range project?
From the point of view of an environmental group like Greenpeace, do we have any
problem with public sector support for renewable energy? No, actually: in the right
place at the right time, it is a good idea and in fact we need more of it. Is this the
best place to put our public support? As I have said, there are many ways in which
we can go to a lower carbon society and most of the reason why we do not do so is
cost. If you accept that economics and cost are the determining factor in how you
decide which renewable energy options you should explore, then sooner or later you
have to come back to the cost.
It is not obvious to me that the barrage is the best place to put public support, at least
not at this point. Again, I come back to the point that we are not saying no to this, but
we are asking whether this is the best place to begin. If we wanted public support, let
me throw out an idea. We know that Britain is in a prime position to explore or rather
to develop an offshore wind industry which, if properly nurtured, could become not
only a huge export industry but could deliver real technologies that could help the UK
and many other countries to deliver a low carbon society. There are considerable
advantages in supporting an industry that might have international significance,
compared to what is essentially a one-off project.
If you wanted to spend £15 billion, how much offshore wind could you get? From
talking to the British Wind Energy Association, they are talking about 6 – 7GW which
is not the same but of a similar order of magnitude to what we would get out of a
barrage, but you would not just get a one-off because you would then get an industry
with a potential for export, as I alluded to earlier, and a potential for much greater
savings further down the line as we have to reach these very ambitious targets
globally.
Why would you choose to support a barrage and not offshore wind? More to the
point, why would you not want to do things that would generally support where you
could use public money to leverage private money in a very big way to support
offshore wind? Let me give you an example. We want to develop offshore wind
farms in many locations down the East Coast. Under the current case-by-case
approach, we have very expensive wires leading from these offshore wind farms into
land, and they have to have landing points, with connection charges, cabling and
substations –which are all a very expensive part of that. Subsea cable laying in
particular is a very expensive part of the development of an offshore wind farm.
If, instead of having these single cables running in to land, you had a very big cable
which ran down and met a lot of them, then you would save on cabling costs at a
system level and you would actually provide an extra capacity running North/South.
In the challenges facing the further development of renewable energy, this
North/South interconnector – all the renewable energy is up there and all the demand
39
is down here in the South-East. So, you solve a system problem and you reduce the
costs.
That kind of strategic public sector involvement is something which probably comes
out at much lower than £15 billion and you would leverage a great deal of renewable
energy. There are thus other options out there for public involvement in renewable
energy and the renewable energy system which, at first sight, appear to be rather
better options than heavy involvement in a barrage. That is what I mean when I ask
whether this is the right place to start. This is not something we would want to rule
out but, for reasons of whether it is the right to start, and looking at all these
environmental impacts, is it really the best option?
The challenge here for an organisation like Greenpeace is that it is not black and
white. It is easy to deal with black and white and we do that quite frequently – we like
to do that, making it clear and simple.
Conclusions
Whilst we certainly need ambitious renewable energy, efficiency and decentralisation
targets to put us on track for long-term 2050 goals, what is the best way of doing
that? There are clearly a number of options.
Roger talked about tidal stream. I have not even touched on wave which, again, is a
technology which we are almost in a unique position to develop in the UK. This could
be an export industry and, importantly, given that we are at whatever it is – 2% of
emissions - it is a technology that could be developed here, that would be of value in
other places of the world, to help them to deliver a low carbon society. There are
thus a number of options and some of the considerations that should be brought to
bear are quite long-term. That is quite distinct from a barrage where, as I said, you
build a barrage and you get a barrage – but you do not have an industry which has
that export and potential for global significance.
It is certainly an option but I have questions about whether, for reasons of
environmental impact and cost, it is the best option. It is not something that we
would want to rule out but, equally at this point, it is not something that we would rule
in. I am sorry that I cannot give you a simple yes or no, if that is what you were
expecting, but I hope you appreciate that, from the global right down to the Severn
Estuary, there are some knotty issues about how we take forward renewable energy
and deliver a low carbon society. The difficulties that it exposes for us are actually
brought to a head by a proposition like the Severn Barrage.
Thank you.
***
Sue Ion: Thank you very much for that, Doug. Doug emphasised, as did Roger, the
importance of looking at things in a holistic sense, in a system sense, as we balance
out all the options that might be available to us in the UK. Although Greenpeace is
neither for nor against, they raise a number of issues that have to be taken into
account as we make choices.
Our next speaker is Bob Taylor from E.ON. Bob will talk to us about the electricity
industry’s views on a tidal barrage like the Severn, and what their response to it
might be. Bob is well known to many people in the audience. He is a board member
40
of E-ON UK, a position he has held since 2001. He is currently Managing Director of
their Generation Division, so he probably supplies many of you with your electricity.
Bob has had responsibility for generation and energy-related R&D for some time, and
the long-term development of clean coal and nuclear generation options for E.ON in
the UK, so he carries quite a diverse portfolio in his mix. He is a chartered engineer
and a fellow of the IET and he is a Member of Council of the University of
Birmingham, amongst his other duties. Bob will talk to us about what the electricity
sector thinks.
41
42
THE ELECTRICITY INDUSTRY’S RESPONSE TO A SEVERN BARRAGE
Mr Bob Taylor: Good afternoon, everybody. I am absolutely delighted to be here.
What an interesting topic – and the presentations that we have for you are building
on the various messages as we go through this. I would like to share with you some
perspectives, from an investor’s point of view, and as a major energy company that is
involved in a diverse range of technologies. Of course, we are both famous and
infamous, depending on your view, for our interests in nuclear, our interests in fossil
and of course a very large renewables business. We are involved in many of the
offshore farms that were mentioned in some of the earlier presentations. Most
recently, we have been in the news with regard to the London Array project and
some of the difficulties that it faces.
First, I will share an overview of the challenge which we perceive that the UK is
facing, because you really have to look at this holistically. I will then look at the
potential role of the Severn Barrage within that context. We really have a challenging
time ahead of us.
The electricity industry faces significant challenges
The Electricity Industry faces significant challenges
y By 2020 a significant amount of the
y Capacity gap up to
25GW by 2020
UK’s existing coal and nuclear
capacity will be closed
y This equates to
over 30% of
current capacity
y A sustained investment in new
capacity is required to close the
supply demand gap
Source: E.ON UK
y New capacity will have to built in an
economic environment that is
focused on fulfilling energy policy
goals of diversity, affordability,
EU Green Package Targets for UK
20 % less carbon
emissions
compared to 1990
levels
15% of Energy in
the UK from
Renewables
20% efficiency improvement
in final energy demand
against BAU (EU wide and
non-binding)
carbon emissions reduction and
renewable energy targets
Across heat, transport and electricity
Page 2
You are probably aware that, over the next two decades, we face what is probably
the most challenging period for the energy system in the UK that we have faced for a
great many years. Some of you in this room may even remember back to the 50s,
60s and 70s, when the UK was building a 10% increase on its capacity every year,
effectively doubling the UK capacity every 10 years. Here we are now in the UK at
the moment, and let us just remind ourselves where we are starting from. We have
about 75GW of plant on the system in the UK and you can see from the diagram on
this slide the kind of mix that we have, with renewables as part of that ‘other’ in the
mix.
It is fairly well known that, over the next 12 years, up to 2020, with the retirement of
our old coal plant in the UK and the nuclear capacity in the UK and a large amount of
that closing out, we need to replace of the order of 30% of our UK capacity. I think
that is fairly well known. What we probably do not consider too often is, what about
the decade after that, because that does not stop? In the decade after 2020, we will
be retiring the rest of the nuclear plants we have. We will have just Sizewell B on the
bars and of course we move to a position where, of the current capacity that we have
on the system, we need to replace of the order of 60% - some 48GW. Depending on
how you want to look at this, it is a major challenge or a major opportunity, as some
of the earlier presenters mentioned. This is a major, major challenge, which we
43
should not under-estimate. In particular, there is the next decade, as we run towards
2015/16.
We have ahead of us a sustained need to transform our energy system and, to do
that, we face choices and trade-offs. There are many people who do not like choices
and trade-offs but leadership is all about making choices and trade-offs. We have
some energy policy objectives around carbon emissions reduction, around security
and around affordability, and that will require us to make some choices over the next
decade. In particular this year, over the next 12 months, with the consultation on the
Green Package and the decisions that we have to make about generation choices,
we face a very interesting and important time. It is a time when we need to be
transparent about the issues and transparent about the costs and about the choices
that we have to make in the UK about some of these technologies.
The Green Package for the EU is another part of the challenge. We have this 30% of
capacity to replace by 2020 and, at the same time, when you actually look at the
Green Package and the 15% of total energy to be taken from renewable sources,
then when you translate that to the electricity part of the sector, as opposed to heat
and transport, we are looking at a challenge there of delivering some 40% of the
electricity generation from renewables.
If that was not difficult enough, at the same time we have a dependence on imported
gas moving from where we are at the moment – 20% or 30% - to 2020 when we will
be dependent on imports for about 80% of our gas requirements. It is rather like a
Rubik’s cube: how do you make all of these choices, and how do you make all of
these trade-offs? As I have said, some people do not like debating those trade-offs
but they prefer to stay in their energy silo: ‘Let’s talk about carbon emissions – that’s
all I want to talk about. Let’s just debate that.’ They prefer to stay in their technology
silos and say they just want to talk about nuclear or about renewables. The reality,
however, is that there are trade-offs to be made, and that is what leadership is about.
We are entering a very important period where we need to show some leadership.
A Severn Barrage would be a unique asset
A Severn Barrage would be a unique asset
Size
If build it would be the largest single generation asset in the
UK
Carbon
Benefits
Take a role in reducing carbon dioxide emissions from
electricity generation helping meet national and international
targets
Cost
Operating
Regime
A capital intensive project and one of the most costly
renewable technologies
The operation of the Barrage brings a distinct generation
shape to the market
Page 3
Let me come now to the Severn Barrage and what that means in the context of our
energy challenges. I shall talk about these four areas [on slide] rather quickly and I
shall perhaps spend a little more time on the last one because that is probably where
my section of the presentations can contribute. I shall be talking about size; about
carbon benefits; about cost, and about the operating regime and what something like
44
the Severn Barrage may mean when it is to be integrated into the energy system of
the UK.
Its size would make it the largest generation asset in the UK
Its size would make it the largest generation asset in the UK
y It would be double the size of
the current largest plant
(Drax) on the UK system
y The size of the project means
that no single generator could
develop and then operate it
Largest Generators in the UK
10
Plant Size (GW)
y If the Cardiff-Weston Barrage
was built it would have an
installed capacity of 8.6 GW
8
6
4
2
0
Severn
Barrage
Drax (Coal)
Teesside
(Gas)
Torness
(Nuclear)
Dinorwig
(Pump
Storage)
What would a consortium look like to develop and operate?
Page 4
Well, it’s big, and I think that message has been conveyed already in the
presentations. Its size would make it the largest generation asset in the UK, at a size
of about 8.6GW. You can see on this slide how it compares to any other single
generation asset in the UK. The largest coal asset in the UK, Drax power station, is
just under 4GW; Teesside, at the moment, is the largest gas-fired power stated, and
so on. This is a very, very sizeable asset.
Just to put it into context of E.ON UK’s generation portfolio, we have about 11GW of
plant on the system at the moment, ranging from renewables, CHP, right through to
our major coal and gas assets on the system. Thus, it would be 8.6GW against our
current portfolio of some 11GW. By the way, we are closing 40% of that over the
next five to seven years, just to come back to my earlier point, if there wasn’t a
challenge there for it. The size of the Severn Barrage would really mean, for a
number of reasons, that it would take a consortium of interested parties to invest,
develop and operate the investment of that scale.
The Severn Barrage would contribute ~1% of renewable energy to the UK’s
final energy demand
The Severn Barrage would contribute ~1% of renewable
energy to the UK’s final energy demand
An 8.6 GW Severn Barrage would generate 1% of UK final
energy demand which is equivalent to
4.75 GW of Offshore Wind Turbines
1 million Ground Source Heat Pumps
1.7 million Solid Wall installations
3.3 million Electric Vehicles
7.9 million Solar PV installations
Source: E.ON UK
Based on 2006, UK Final Energy Demand (FED) = 1,663 Page 5
TWh
45
It would make a contribution to carbon emissions and I think that point has already
been made – I think it is something like 17TWh, a capacity factor of 20% or so. It
would contribute to approximately 1% of the renewable energy requirements of the
UK – so that is transport, heat and electricity. It would contribute about 4% if you
looked at it in terms of the UK electricity energy needs. It is broadly equivalent to
some of these other choices that you can see here, taking account of the various
capacity factors and the contributions of energy that each of these choices would
make. From a carbon emissions point of view, therefore, we can see it making a
material contribution.
Barrage costs would require a unique approach
Barrage costs would require a unique approach
y At commercial discount rates the
estimated costs of a CardiffWeston barrage would be
significantly higher per KWh than
current technologies
y Some level of HMG involvement
will be required due to the projects
economics (e.g. RO extension,
other support mechanism’s,
financing etc)
Source: Sustainable Development Commission
Does this project deliver the policy goal of affordability?
Page 6
What about costs? This information is taken from the SDC report and, in this
diagram, you can see a range of long-run generation costs from the various
technologies. I have deliberately taken this from SDC: every time I put up a different
picture of generation costs, people want to talk about the basis of them. Broadly, I
have to say that I agree with the figures that are given here and of course you then
get into the issue of financing and the cost of capital associated with financing what is
a very significant investment. This ranges from – and we shall hear more about this
in a moment – some £15 billion up to £23 billion in total investment. At commercial
discount rates, if we are looking at the overall risk associated with the Severn
Barrage, you can of course see that it would be significantly higher than the other
costs associated with technology choices that we have. There is a range of ways in
which support could be offered to the Severn Barrage but it certainly looks as though
it would require significant support – either significant support and/or a combination
of how the Government may look at managing some of the risks. This is a massive
construction project and, once you overcome the construction risk and you have
certainty around that, then of course you have a different risk profile as you go into
the operation of the project. This all needs to be looked at as part of the feasibility
study.
The big question, as you can see at the bottom of the slide, is that we ticked it on
carbon emissions but does this project deliver the policy goal of affordability. Let’s
face it, you are spending some £20 billion for 17 TWh. You can build a fossil-fired
power station for much less than that, and you may build one fossil-fired power
station to delivery your 17 TWh. The other side of that, of course, is that there are
the carbon emissions that a fossil plant would contribute, so you might spend £2
billion building an equivalent fossil plant that would give you 17 TWh, as opposed to
46
£20 billion building the Severn Barrage, delivering the same energy into the system.
These are all part of the trade-offs and of course there is no one right answer in this.
As we shall come to, this requires a diverse approach to what we do with our energy
system.
A number of operational challenges would be faced
A number of operational challenges would be faced
Demand met by Thermal and Barrage Capacity
60
y Tidal power is variable but highly predictable
Output (GW)
50
y Shape does not necessarily match peak
demand periods
40
30
20
y Therefore challenges are:
10
0
00:00
12:00
Time of Day
Residual Generation
60
00:00
Severn Barrage Generation
y It adds additional complexity to scheduling
in the market through peaks and troughs
Demand met by Thermal, Barrage Capacity and
48GW of Wind
50
Demand (GW)
y To big for one generator to take in its
operational portfolio
40
y This will then feedback into price volatility
30
y Need to be supported by very flexible
assets
20
10
0
-1000:00
12:00
00:00
How will the market reward it?
Time of Day
Baseload
Flexible
Wind
Severn Barrage Generation
Page 7
Source: E.ON UK Analysis
Let me move on to the operational challenges that would be faced. From the
diagram on the top left hand side of this slide, you can see a typical November day
with the demand profile across that day, and you can see the contribution that would
come. I have literally take the information from the various reports, and shown a
typical contribution that would be made, and the timing of that contribution, to the
overall energy demand during that typical day.
Tidal power is variable but the benefit, certainly relative to wind, is that it is
predictable. Even though the shape on this slide does not necessarily match the
peak demand periods, there may be options to look at how you can compensate for
that as part of the overall system. You heard a little about that earlier.
In the diagram below, for effect, as well as the barrage I have put a very large
amount of wind super-imposed onto the system there – some 48GW of wind. I have
assumed that this was a very windy day and that that wind was contributing to the full
extent that it could across that day. You can see a very extreme picture of what that
does to the operating regime. You move from periods when you have excess
capacity and excess on the system – a negative position – and you see a picture
where you start to constrain off your baseload generation. You also create a very,
very interesting profile for your mid-merit and flexible plant. Granted, that is a very
extreme picture.
On the other side of that, of course, that red band can be anything from 100% to 10%
or less. We have a very large wind portfolio, particularly during the winter peak
periods. If we look at the capacity contribution from our wind portfolio, we actually
get figures – and this is fairly well geographically dispersed – of just under 10%. We
could thus have a situation where that red band could fluctuate from the width shown
there on the diagram to 10% of that thickness and we have to cope with and
accommodate that into how we operate the system.
That introduces some very interesting aspects. In particular, of course, it builds a
requirement there to have a very flexible portfolio, supporting this mix on the system.
47
It certainly brings greater complexity. The amount of energy that would be traded
through what we call the balancing market, which is a shorter-term market in the way
that the electricity system operates, would be massive in these kinds of scenarios.
Indeed, what we are showing here is in fact exposing a debate which is important
and currently starting and underway. Regardless of what we do with the Severn
Barrage, if we are looking at such large volumes of wind on the system, then this is
the kind of debate that we have to have anyway. All I am saying is that the Severn
Barrage contributes even further to that debate on how we cope with such large
amounts of variable power on the system.
It emphasises three areas into the long-term. One is the role of flexible plant on the
system and how it is used as part of an overall diverse, flexible energy system. It
also emphasises the need for and the role of interconnection, and the increased role
of interconnection. If you look at any of the markets that operate with very large
amounts of variable power on the system, whether that is in Denmark, or Northern
Germany where we have 22GW of wind on the system, you see some very large
amounts of interconnection. You see a very flexible approach from the other plant
that is supporting that on the system.
The bottom line, however, is that in fact we could be move from a situation where we
have some 75GW on the system in total capacity terms, to 120GW on the system.
Essentially, we are moving to a situation where we have more variable and lower
load factor generation plant on the system. How do you reward all of that capacity
that is on the system? First, how do you make it work, and then how do you reward
investors who are looking to contribute, whether they want to build renewables or
flexible plant on the system? It creates some very interesting challenges which of
course have to be addressed as we go through the next 12 months, with the
consultation on the Green Package and the role of large amounts of wind, and also
as part of the feasibility study that we are going to conduct into the Severn Barrage.
These are all important issues which we need to address soon. I hope you can see
that, depending on your view on some of those issues, it has a fundamental effect on
how much capacity, and what type of capacity, you put onto the system. I will leave
that there, because I am on a hobby-horse, as you can probably tell.
Conclusions
Conclusions
y The project fits with energy policy goals of climate and
security of supply but a compromise might have to be
made on the goal of affordability
y Its generation characteristics present a challenge that
will have to be considered from a wholesale market
perspective
y These challenges have to be fully explored as part of the
feasibility study
Page 8
In conclusion, the project fits with the energy policy goals of climate and security of
supply. I hope there are some themes where we can see that it definitely plays to
that. Being very diplomatic here, a compromise might have to be made on the goal
of affordability. I hope you can see that there is a very large cost associated with this
48
choice, but it is something that needs to be looked at properly as a part of the
feasibility study.
Its generation characteristics present a challenge that has to be considered, and
considered soon, from a wholesale market perspective. How do we want this market
to work? I am afraid that it is very similar – if you take it in conjunction with large
amounts of wind on the system, then we really have to think about how we may have
to re-design aspects of the way the market works. These challenges have to be fully
explored as part of the feasibility study.
We are facing one of the most exciting times over these next two decades. I am an
engineer, although I have done a few other things since, but I am still and engineer:
what an exciting time this is for people to become involved once again in a new wave
of transforming our energy system.
I implore people, when looking at these debates, to think about them holistically. I
have been involved in many debates, as you might imagine, because of Kingsnorth,
because of nuclear and also with some of Doug’s [debates]. A microphone is often
put in front of me, with one of his colleagues, and I have a great deal of respect for
some of the work that Greenpeace is doing to promote decentralised energy and
particularly CHP. However, if someone is telling me that they are saying no to
nuclear, and no to any contribution, albeit from a smaller amount of coal onto your
system, we have to manage a very difficult transition here. The transition, particularly
over the next two decades, will be to a low carbon economy and we have to do that
with due regard to security and affordability. If we lose the focus on those two issues
as part of the trade-off, I can tell you that the people out there and our customers will
lose interest in carbon emissions. We really have to take this in a balanced and
structured way, but also in a determined way, to meet the challenges ahead of us.
Thank you very much.
***
Sue Ion: Thank you very much, Bob, for giving us a run-through from a utility
perspective. You have led us to believe that E.ON would not be first in the queue to
sign up to the Severn Barrage, unless that was as part of a consortium and the whole
thing was considered as part of the UK’s generation mix. We hear that message
time and time again, about understanding the totality of the mix.
Our final presentation before the discussion session will be from Yaver Abidi, a civil
engineer with a wealth of experience as a consulting engineer right across the world
– North America, Asia, the Middle East and Africa. He is currently Group
Development Director for the Halcrow Group and holds an MSc in Soil Mechanics
from Imperial College, London. He has also studied at the Stanford Business
School.
Yaver will talk to us about some of the interesting engineering challenges associated
with the delivery of the barrage. The title of his presentation was ‘Financing and
Project Management Challenges’, but he also has some very interesting facts and
figures on just what it will take to build this barrage, if indeed that is the decision that
is eventually taken.
49
50
FINANCING AND PROJECT MANAGEMENT CHALLENGES
Yaver Abidi: I have chosen to look at this project from the point of view of financing
and project management. What I hope you will see, as we talk about this, is that no
matter how you look at this project – and we have seen several perspectives
presented on it – a number of the issues keep coming back, which we need to
consider. It is looking at this project holistically, which is a point that Bob just made,
that really matters.
As we talk about matters which, at the present time, with the environmental
uncertainty that faces this project and the many interest groups that are involved in
the debate, I hope you will see that it is really important for us to look at this project
not as just a study because, even at this stage, we should think about it right through
to operation. This is a power project – it is not an environmental problem, but a
power project. It is important to think right through to the end because that is what
will help us, even at this early stage, to address the issues in a balanced and holistic
way.
We could talk for hours about the project management and financing challenges of
this project, but I will try to pick out a few things which I hope will add to the
perspective that you walk away with after this seminar.
The project
The project
Black and Veatch (2007) SDC research report 3, Severn Barrage Proposals
Let us just look at the project. You have seen this image already in Roger’s
presentation but I will just pick out a couple of points that interest me from an
engineering and delivery perspective. The project would involve placing turbines in
the deepest parts of the estuary. You will not be able to make this out from the slide
but, at the deepest point, this is at minus-30m. We would be putting in place
structures that extend from minus-30m, up to plus-10m or so, which means they
would be 40m high.
Just to put that into perspective, I am a dams engineer and 40m high dams are pretty
significant. In fact, large dams are defined as those above 15m in height and so, for
a dams engineer, this would be an interesting challenge. We are putting it into this
estuary with this massive tidal range. It is worth just getting a perspective on what it
is that we are setting out to do here.
51
The scheme
The scheme
Cardiff-Weston
La Rance (1966)
Annapolis
(1984)
Length of barrage
16.1 km
0.75 km
0.20 km
Basin area
480 km2
22 km2
N/A
Turbine generators
216 x 40 MW
(8,640 MW)
24 x 10 MW
(240 MW)
1 x 19.6MW
Runner diameter
9.0m
5.35m
7.6m (Straflo)
Average annual
energy
17,000 GWh
540 GWh
<50 GWh
Sluices
166 (35,000 m2)
6 (900 m2)
2 (130 m2)
Ship locks
2No 360x50 m
1
N/A
Construction
period
5-10 years
6 years
Here it is in comparison to the two tidal power schemes which have been in
existence for some time in the world. You can see that it is much longer and the
basin area is much bigger and the generating capacity is much higher. The size of
the turbines is significantly bigger, the energy generation is high, and so on and so
forth.
La Rance
La Rance
crédit EDF MEDIATHEQUE
Let us have a look at these two projects. Roger showed one picture but I would like
you to look at this one slightly differently. This is the La Rance barrage generating,
and the white water downstream of it makes you realise what this is all about. This is
not some passive element put in to a marine environment but it is a generating plant,
which will have some impact on the barrage. This is a very nice photograph, but it
shows you what a tiny little thing La Rance is. It has been around for nearly 45 years
and therefore it has certainly proved that you can build in the marine environment –
you can put in equipment of this scale and it will operate satisfactorily for extended
periods of time.
One of the points you might have heard is that the lifetime of this barrage is 120
years. I have had the privilege of working on the rehabilitation of some hydro-electric
plants in Northern Ontario that are nearly 100 years old and these things are still in
pretty good shape. This is quite different from some of the fossil fuel plants and so
on, in the sense of its longevity and stability.
52
Annapolis
Annapolis
Courtesy Nova Scotia Power
This is another scheme in the Bay of Fundy in Canada. This is actually a test
scheme which has been running for 25-odd years. Again, this is in generation mode
here and a sluice is open, so there is a single unit where you see most of the white
water and then, to the side, there is an open sluice which lets the water through.
This is just to help you to benchmark what we are doing.
Financing challenges
I will talk about the financing challenges because this is part of the debate. Once
again, the point was made earlier about what it would take to get this thing done. We
must think about that because it may be one of the key factors in determining how we
take this forward.
The investment
The Investment
Mgmt and
supervision
3%
Planning and
legal
2%
Site
preparation
5%
M&E off-site
11%
Caissons
32%
M&E on-site
34%
Gates
7%
Embankments
6%
Not including compensatory habitat, transmission system strengthening
Let us look at the scale of the investment. In case you cannot read this, in Halcrow
we have been looking at this project for some time and we are conscious that many
of the studies done on it were done in the late 1980s, in a completely different
context, in a completely different power market, by a group of enthusiasts who
wanted to propose that this project go forward. If there are members of STPG
present, I would be in exactly the same boat as you. What we have learned in the
UK over the years, however, is that there is a tendency of project proponents towards
what is called ‘optimism bias’. Now, the Government has very clear guidance that
53
you do not set out on a project with a nominal 15% contingency because experience
shows that you really need to start with a very substantial uplift on the cost estimates
of the project. We believe, based on the original costing done but by simply changing
the contingency, that we should consider this project at something north of £20
billion.
The other thing that you might find interesting is the pie chart on the right of this slide.
The big yellow slice represents the concrete caissons, while the salmon colour and
blue on the left show the mechanical and electrical equipment which accounts for
45% of the cost of the project. In both cases, as I shall show you, there are
significant challenges for the industry to deliver these and therefore the case for not
starting out with an over-optimistic cost estimate is extremely strong.
Private or public sector?
Private or public sector?
•
•
The SDC study concluded that “The Government would need to be
a key part in the development and promotion of the project. A Public
Private Partnership (PPP) is considered to be a suitable approach
for developing the project.
In a 2003 review of PFI projects, the NAO concluded:
– PFI incentivises a consortium to take a longer term approach to design and
construction
– PFI incentivises the consortium to deliver the built asset to budget and on
time
– The whole life cost approach under PFI encourages good quality design
and construction
– Expert opinion and experience support the conclusion that these
incentives are working
•
The private sector will have to play a role in this project because of
its sheer scale and because it is best placed to manage some of the
risks
Should it be done in the private or public sector? The days of that discussion are
long over. We have this free and open power market in the UK and, over the last few
weeks, as I have become involved in this project, I have been reading about the
intricacies of balancing mechanisms and gate closures and so forth. This is really a
hugely complex business.
In terms of delivering this project, there is no doubt in my mind that it will be delivered
in some form of public/private partnership. I use that term very carefully because, as
I will show you with a couple of case studies, government has tried in the past to
outsource the whole thing through PFI. I will show you two examples in which
Halcrow has had some involvement, which will illustrate the need for partnership in
the delivery of this project, which is very high relative to more traditional projects. If it
was a highway project, one might look at it differently.
54
Can project finance be arranged?
Can project finance be arranged?
Largest project finance deals from Project Finance International Magazine
First, let us look at the scale of the project. We are looking at a £20 billion-plus
project and it would be a very large project financing deal. If you cannot make out
the figures on this slide, the largest one that I can find in Project Finance International
magazine, which does a ranking of these project finance deals (in dollars), is $24
billion, or £12 billion at today’s exchange rate. This would therefore be a very large
project to finance.
What does that mean? When you look at something like the Channel tunnel, the
financing of that involved over 200 banks for a massive syndication of the loan.
However, that was at a time when the finance industry was in a different place but we
have come a long way. Putting aside today’s immediate crisis, where bankers have
suddenly discovered that there is no free lunch and that you cannot simply wish risk
away, when the thing gets back to its rightful place, there will be enormous capacity
in the market to create a project financing opportunity - there will also be lots of
players who will want a small part of the risk.
You will also see that project financing in here – oil and gas, and roads and
transportation – is reasonably well understood. Types of projects play a big role in
this. The other reason why so many people would be involved would be because
this would be somewhat unfamiliar to them. I am sure that they could do a fossil fuel
power station better than this. Here, however, the risk profile will be perceived to be
high.
Case study – Channel tunnel
Let us look at two case studies. First, there is the Channel tunnel – and I will come
back to some of the points I make later on. I will try to highlight those things which I
think are interesting to learn from this project.
First, there were significant conflicts of interest in the way the project was originally
formulated. The people who pushed it forward were a group of contractors who were
in prime position, so they contracted with themselves and then stepped away from
the actual SPV that was created to deliver the project – but conflict of interest
remained. I would like to pick out a couple of points that you might find interesting.
It was of course approved by the government, Margaret Thatcher’s government of
the time, as a PFI. In other words, this was a purely privately financed scheme.
Similar intentions were being expressed about the nuclear power plants, and
decommissioning costs would be entirely borne by the proponents of the project. I
55
think it is a good thing that the government starts with a realistic frame of mind but
the reality is sometimes different.
This project had many problems and there are a couple of issues that are pertinent to
this discussion now. Sir Alistair Morton said at some stage: “The project was
assembled round a hole like a Polo mint. There was no client driving it forward with a
vision of what the operator needed.”
It is really important to think about the ultimate operator of the project and they
should be at the centre of some of the decisions that are made.
There were various attempts to manage risk in the project through contracting
strategies and I will talk a little about the procurement of this under the heading of
project management. There were many problems and a good deal of intervention;
costs went up dramatically, as you will recall, leading to enormous financing
problems. This project has been re-financed so many different times and I am sure
that you will recall all of those things.
An important review of this project is that both the revenue forecasts and the
construction cost and cashflow were underestimated from the beginning. This seems
to be a feature of those people who are the beginning of a deal. In the finance
industry, they sometimes talk about something called ‘deal fever’, when everyone
becomes very excited and all they can see is that the glass is half full. There are
some lessons to take forward as we embark on what might be a very enormous
challenge for the UK industry.
Case study – High Speed 1
The other project where Halcrow has been very central in the delivery of it is the
channel tunnel rail link, now known as High Speed 1. Yes, revenue forecasts were
too high. The private sector did not have the financial strength or equity capital to
assume the risk that the Government had intended it to take. This was an important
point and you will remember the Deputy Prime Minister intervening at some point to
help out on this project.
Because of the way risk was managed, the taxpayer will continue into the 20s of this
century to bear some risk on this project in terms of the repayment from revenues
that will come from it.
Some of the lessons learned were that projects like this require a clear understanding
of where funding will come from, from the outset. That is the basis of continuity and
momentum in these projects and this is something that you would need to create for
the Severn Barrage fairly early on. You need dedicated people with an
understanding of where the money is coming from. You have to have the operator’s
view and you have to be realistic about the cost estimates and so on. So those are
just a few points to which I shall return later.
56
Drivers of private sector investment
Drivers of private sector investment
•
•
Public sector tends to focus on unit cost of energy to prioritise
options and determine viability
Private sector concerned with:
– rate of return on investment
– the price of electricity including the effects of any price incentives
– look in a ‘joined up’ way at prices and costs
•
Decision driven by perceptions of risk by stakeholders:
government, wider industry, promoters, financiers, constructors
and customers
Price Risk
Costs
Revenues
8Electricity price
8Willingness to pay
8CO2 credits or RO
certainty
Technical Risk
Financial Risk
9Capital cost
9O&M cost
9Technology risk
9Environmental compensation
9Weighted cost of
capital
9Credit risk
9Capacity Factor
9Build Time
8Planning delays
8Government interference
9Contractual risk
9Financial failure of
contracting parties
9Industry backlash
The other feature of private sector involvement in these projects is that you have
seen, even in the previous presentation, a relative presentation of the cost of this
project – the unit cost of power generation versus other technologies. It is very
common in the public sector to talk about unit costs but in fact the private sector is
looking for a return on investment. They want to make sure that there is an adequate
return on investment and that they can service the debt they take and return profits to
their shareholders at an appropriate level for the risk they are taking. They are very
interested in this joined-up way of looking at prices and costs and so the power
market in which this project operates – as we saw in the last presentation – is very
critical to its success, from the private sector’s point of view.
Decisions are driven by the perception of risk by various stakeholders. On this slide I
have put up a variety of risks – a price risk and so on, in the table at the bottom. I
have tried to classify as green, amber and red. There are those risks which should
clearly rest with the private sector; those risks that are shared between government
and the private sector, and those risks that may be unfair to be taken on by the
private sector, or where you would pay excessively for the private sector to take
those risks on – that is the other way to look at it. There is no fairness in business,
but there is a cost.
Price risks
Price risks
www.apxgroup.com
57
If you look at some of the issues that would determine the private sector’s willingness
to participate in this project, electricity price – which I will show you here – is a big
feature. This is a daily graph of both the volume of electricity traded and the unit
price per MWh paid in the course of a day. The scale at the bottom of the slide is in
half-hour lots, so this goes up to 48, but this is just a day and you can see how
volatile the price is. When the barrage is generating – in the present regime,
assuming nothing has changed, that would determine how much more or less
valuable the power is. You certainly contract to provide power at a certain rate but
the marginal costs of power determine what you are actually paid. That is a very
important factor for a project that generates power on the cycle of the tide rather than
under the control of the operator. So they will be generating power when there is an
ebb tide with which to generate it, or not, and thus the pricing risk is a very important
factor in the minds of the private sector.
Drivers of private sector investment
Planning. I would think that if this is to be a public/private partnership, then the
private sector would play a role in going through the planning process, because they
have information that is valuable in the whole process. However, can they afford to
take the risk on the duration and extent of the planning process? I am sure you are
all familiar with the fact that the Government is planning to change, or has a White
Paper, to modify the planning process in the UK, but it is based on the experience of
seven years of planning for Terminal 5, and five years for other major projects.
There are extended periods which just create uncertainty for the investor and leave
them wondering when the project will actually be done.
On the bottom right of this slide, I have put ‘industry backlash’. As was discussed in
the previous presentation, a project like this creates the need to reward others, or
somehow to compensate them for having capacity in the system to cover the times
when the barrage is not generating and yet demand is high, and yet to turn off those
plants when the barrage is generating, so that we can have a lower total carbon
emission. It is important, therefore, that this project is about taking the whole industry
along: the stakeholders are many and diverse.
Financial viability
It is an expensive project. We have done an economic analysis of this project on the
basis of the figures that I showed you, with a high level of contingency, based on the
optimism bias recommendations of the Government.
Price risks
The wholesale price of electricity would have to be about three times as much as it is,
on average, during these daily graphs that I showed you. On the right of this slide,
there is the scale for the price and you can see that, for most of the day, it is
somewhere between £40 to £60 per MWh at present. The bottom one, which is just
a different day, has a different scale: this was actually 20 May, just a couple of days
ago, when power traded at about £80 per MWh.
On its own, this project does not make sense. If you look at it simply as a power
generation scheme, it is its other benefits that make it possible for it to be brought
into the realms of practicality. I am catholic on whether or not that is a choice we will
make but I would suggest that it is a choice we have to make: it is not a simple
comparison between what the electricity price would have to be in order for this
project to be viable or not. We have had some interesting discussion about that.
58
Support mechanisms
We need support and this bring me back to the idea of the PFI approach - here you
are, and here is your problem - to a public/private partnership approach, which is not
as common as you would think. I tried to see how many true public/private
partnerships there are and I think the Government has found success in the PFI
model for delivering schools, hospitals, defence facilities and so on, and therefore
they have grabbed that. However, this project is not about PFI. It is not about
getting it off the balance sheet and off your back but it is about partnership.
There will be key things that the public sector, the Government, will have to do in
order to make this work. They may involve sovereign guarantees, to bring down the
cost of borrowing.
Financial viability
You will remember that, in the previous graph, here, we were talking about an 8%
rate of return as what the private sector would need but it would depend on the cost
of borrowing and their understanding of risk, which would determine the rate of return
they were looking for. Sovereign guarantees are something that can happen.
Support mechanisms
Support mechanisms
•
•
Because of its scale, its complexity and drawing on lessons
learned from previous major projects of this nature we
conclude that:
The project should be a true PPP with the public sector
managing the risks that require political support or policy
measures such as:
– Leadership of the planning approval process and of any necessary
habitats directive exemptions
– Carbon credits or renewables obligation certainty
– ‘Support’ price or other transfer mechanisms to maintain minimum
price
– Sovereign guarantees
Is the Government used to doing sovereign guarantees? Of course it is. The
Treasury is just buying all this bad debt off the banks. They intervened in Northern
Rock, but let us not do it in extremis – that would be my recommendation – but let us
do it from the beginning. Let us not find ourselves with our trousers down, having to
cover ourselves very quickly, but let us do it from the beginning. That is my
recommendation.
Support price – there may be a need to compensate the barrage operator to make
the project work for them.
Planning approval and so on is a process that will need leadership and I will come
back to this, but this project falls under the EU Habitats Directive. Getting an
exception from the Habitats Directive, which may be necessary, will need
government and the developers to work together to make this happen.
59
Project management issues
In the second half of my talk, let us look at some of the project management issues.
Procurement issues
This is a huge project. The Channel Tunnel was £10 billion, and so £23 billion is a
massive project. Do you tender a project like this? These are the kinds of questions
we have to talk about.
If you are doing a public/private partnership, can it be done in that spirit of
partnership? Can we construct ways of getting the private sector to be efficient and
to deliver a value-for-money outcome, without going through the tired old competitive
tendering process? I would suggest that this project raises that challenge because I
do not know how many people could undertake this project. It would take a big
consortium, as we have discussed earlier, and how many consortia do you want?
Then, as was the case with the Channel Tunnel, there were four bids which were
completely different. There was rail only, raid/road, bridges hung on cables – all
sorts of ideas but, in the end, there were four consortia that had completely different
proposals. The decision to award was made miraculously in two months – I do not
know how it was done, but it is interesting to think that you can make yourself a real
problem by going through competitive tendering and finding yourself in a situation
where you just cannot compare the options. I know there are some very clever
people out there but these things can become very complicated.
How do you incentivise the parties to deliver the greatest efficiency and
effectiveness? This is worth a great deal of thought, and it is worth a great deal of
thought now if we are to engage the private sector.
Procurement issues
•
•
•
Is competitive tendering possible or desirable on a project
delivered through PPP on this scale?
How should it be structured to incentivise the parties to deliver
greatest efficiency and effectiveness?
How should the generation equipment be procured when there
are 3 – 4 major manufacturers whose track record is:
Manufacturer 1 (50% market share)
Since 1936:
- Installed capacity 4,500MW
- 170 generators in 50 plants
- 300 turbines
Manufacturer 2
Since 1955:
- 180 machines installed
- 0.8 to 8.4m dia
- Up to 50 MW
I want to show you something very interesting about this project, which was a
revelation to me. I am not an expert in bulb turbines. There are three or four major
manufacturers of bulb turbines in the world – it is a cottage industry. This is
manufacturer No. 1 – and I am not advertising anyone so I have not named them –
and they claim to have 50% of market share, but I had never heard of them, and I
had been in the hydropower field for some time. I discovered that they are a massive
conglomerate – they had bought all the cottage industries and put them together
basically, so collectively they have done this.
60
But look at the installed capacity since 1936 that they have delivered – 4,500GW.
Half of this barrage has been done by them since 1936. They have done 170
generators, and we have 210 in this barrage – and they have done this over the last
70 years, with 300 turbines. Similarly, manufacturer No. 2 is a very well-respected
and known continental manufacturer – whoopee, 118 machines installed since 1955.
We have 210 to do in five years. So what will you do? Will you go out to competitive
tender? There are only three of these guys and they do it in their garages. There
are some really interesting challenges here.
Some construction challenges
Some construction challenges
•
For a construction programme of 7 years the barrage would require:
–
–
–
–
•
•
5% of the total UK cement sales
3.5% of the concrete aggregate sales; or locally it would consume
225% of the concrete usage in South Wales and
all of the output of fine aggregates from the Severn
At peak, the barrage would require 44,600 workers per year out of
186,000 construction workers in the infrastructure sector in 2006
It will require new bespoke specialist plant
– dredging in rock will need very heavy duty equipment working at depths
which can only be achieved by the largest dredgers in the world and in
stronger currents than are normal
•
•
Each caisson will need almost 20m depth of water to float; these
challenging dimensions will require the construction of new
construction facilities which will be significant harbours in their own
right
The very tidal conditions that make this site attractive for power
generation make it challenging for the installation of caissons and the
closure of the barrage
Let us look at some construction issues, and I will pick out a couple of points from
this slide. You can read this for yourself and see that there are 45,000 workers
required. The UK’s current 2006 workforce in the total construction industry was
about 1.86 million, of which 10 per cent work in the heavy infrastructure field that we
are looking at. Thus, roughly a quarter of the people who are working in construction
want to work on this project, and would be needed for it. It would require quite
specific and bespoke specialist plant. I hope that this is where my talk will become
interesting because I will show you some pictures of some of these things.
These concrete caissons are huge and they will be pretty amazing to construct. Of
course the tide, which is the source of the energy, is also the challenge.
Competition for resources
Let us look at the competition for resources. At the same time as this barrage may
be going ahead, if we undertake it, there is of course the Government’s nuclear
programme. What sort of skills does that need? Well, there is mechanical
fabrication and electrical equipment, and concrete – it sounds like much of what we
have to do here. So, the same 186,000 or however many people there are – and, of
course perhaps I should not say this, but our immigration policy is moving in the
wrong direction for this – we need people to come and build these damn things, and
they will all be happening at the same time. Why? Because the cliff is right in front
of us, as was shown earlier, and we need this power.
In terms of the labour force, therefore, the construction will be stretched in many
different directions because of the nuclear power plant. The first round of nuclear
power stations will be being built, from broadly 2013 through to 2020, so more or less
contemporary.
61
Interestingly, one of the lessons that I forgot to mention on the Channel Tunnel Rail
Link was that the second phase of that project saw cost escalation. As part of the
consortium that worked on the project management of that, we are very proud to say
‘on time, on budget’ but for Phase 2 of that, the connection to St Pancras, actually
the costs increased. Why was that? It was because there was a great deal of
competition for labour and for materials and so there was significant price escalation.
Is 60% optimism bias wrong? Everybody will be building those as well, and High
Speed 2, and, and, and - so we will be competing in a competitive market place.
Specialised vessels – 1
Specialised vessels - 1
courtesy: Rijkswaterstaat Adviesdienst Geo-Informatie en ICT
(AGI)
I went on the web and looked at the Scheldt barrier in Holland. I mentioned bespoke
plant and these ships were constructed especially for that project. The one at the top
is for foundation improvement and the one at the bottom is for moving some of the
main pieces of plant around.
Specialised vessels – 2
Specialised vessels - 2
courtesy: Rijkswaterstaat Adviesdienst Geo-Informatie en ICT
(AGI)
This slide shows some more of that – this is putting some gates in to one of the
barriers that forms part of that massive flood protection for Holland.
62
Caissons
Caissons
• 54 turbine caissons:
– 79.5m x 77.4m x 40m height (excluding public
road).
– Float-out weight 126,000t; final weight 270,000 t
– Level of underside of installed caisson – 28.65m
OD. Axis level of turbines –17m OD.
• 46 sluice caissons
– 89.5m x 46.5m to 52.5m x height 24m to 34m
– Float-out weight 58,800t to 83,300t; final weight
84,000t to 126,000t,
– Gates 16m wide x 9m to 17.5m high
There are 54 of these caissons to be built and they are 80 x 80 x 40m high, as I
mentioned to you earlier. They weight 126,000 tonnes when they are floated out.
Let’s get this into perspective: a typical, large bridge caisson that I was looking at
would be 10,000 or 5,000 tonnes – those are not massive, but this is huge.
The closest thing I could find to this is a project with which I was marginally involved
in Newfoundland where, for an oil platform, they made a massive concrete caisson –
it was the Hibernia field, for those of you who know about it. This single caisson was
built as a major project in its own right and it was 450,000 tonnes, which was really
big – but it was a massive project in its own right for which you had to build a lot of
enabling facilities.
St Petersburg Barrier
St Petersburg Barrier
• 64 radial sluice
gates 24m wide.
• Two of six sluice
structures floated
to site.
• Cast in two
sections each
Each section was
150m X 30m X
10m (draft 4m
• 18,000t each
• Cost of the
completion works
>$2 billion
• 110 m wide
navigation
opening closed
with a 2500 tonne
steel vertical
rising gate
This is a project we are working on the completion of in St Petersburg. That caisson
is 150m by 30m, and we had 80m by 80m, by 10m high, where ours is 40m. They
weighed 18,000 tonnes each. You can see what is involved in moving these things
off, and only two of these were done – there are actually six in there but four of them
were constructed in the dry, using a cofferdam. Two of these were actually floated
into place but I just wanted you to get a feel for the magnitude of what we are doing
here. By the way, both of these had massive problems after installation, in terms of
settlement, foundations and so on. It is not easy to do this – you don’t just plonk
them down, and they are not Lego blocks.
63
Construction dock
Construction dock
courtesy: Rijkswaterstaat Adviesdienst Geo-Informatie
en ICT (AGI)
In an earlier SDC report, there is talk of building these things in dry docks. As time
went on, there was talk of doing these on the Continent and floating them out and so
on.
This, again, is from Holland. You have to build a really big dry dock in order to build
some of these caissons. These (on slide) are quite small – they are 10,000 tonne
blocks that formed part of the barrier. You can see on the left in this picture the
cofferdam that contained them and, on the right, once it is flooded so that they could
be floated out and put in place. The interesting point is that, to float the ones that we
need, you would have to go down to minus-20m. Ports today that accommodate
super post-Panamax vessels are at minus-15m, so this is a deep, dry harbour, or set
of these, that you have to build. Just imagine the planning application for this! I am
not trying to make this sound impossible but I am trying to make it sound like a
fantastic challenge. I am very excited about the project, although whether it goes
ahead or not is a matter that is much bigger than me, but it is fascinating.
Brouwers Dam – caissons in place
Brouwers Dam – caisson placement
Brouwers Dam – caissons in place
courtesy:
Rijkswaterstaat Adviesdienst GeoInformatie en ICT
(AGI)
courtesy: Rijkswaterstaat - Adviesdienst
Geo-Informatie en ICT (AGI)
Here is what putting a caisson in place looks like. These are tiny little ones – these
are Lego blocks, but they are the closest thing I could find. You can see a lot of
manoeuvring by boats and so on, to put them in place.
Here are some of them in place, and this is what starts happening as you start
closing an estuary, in this case, and the tides go in and out.
64
Brouwers Dam – caisson closure
Brouwers Dam – caisson closure
courtesy: Rijkswaterstaat - Adviesdienst
Geo-Informatie en ICT (AGI)
This is the closure. For any of you who have worked on dams, closure is really
difficult. All the water is trying to get out at the same place, so that the flow is
unbelievable. Even if the sluices are open, and even if the barrage is partly built, we
have the 16km-wide throat in the Severn Estuary that we will slowly squeeze, so that
it becomes harder and harder for the water to get out. They had some pretty big
problems here, too. They had a lot of sediment movement and erosion of the bed
and so on, which they had to take care of. These are surmountable construction
challenges but, nevertheless, that is what we are getting into.
La Rance turbines
La Rance Turbines
crédit EDF MEDIATHEQUE
Source: Andritz Hydro
Source: Voith Siemens Hydro
Let’s look at these bulb turbines that we are going to have. The one on the top left is
La Rance, and the others are from various sources. I am sure that you cannot make
this out but these things are made – they are not just things that you forge or beat out
of a tin sheet. A great deal of work goes into making these. These are adjustable
vane blades and they need some very specialised milling kit and so on, which has to
be put together. The challenge here is that, because we are going to be so much
bigger than the cottage industry that exists, which delivers about 15 of these a year,
and we want another 30 a year, then we will create an industry for this one-off
project. That point was made earlier, about the fact that this is a one-off project. We
have to internalise the costs of that as well. Is a 60% optimism bias too high? I do
not think so.
We will have to set up an entire global supply chain, to deliver these massive
turbines. I think the 8.5m diameter is the largest that we have and we are going up to
9m, so they are bigger than anything that has been done to date. We will have to get
65
a consortium of these people to work together, because not one of them can do it.
We will have to set up manufacturing plant and supply chains that are new.
Meeting these challenges
This review of financing and project management - which I will freely admit that I
have just skimmed over to pick out some interesting points that you might find useful
and interesting to think about, as I have – creates a very strong case for engaging
the actors in this project early. The industry, both in the UK and in Europe, needs to
understand.
Let me try to illustrate a simple point. This barrage generates power at the time
when the tide wills it. We have an interconnection with France. I looked at probably
the same November day that you were illustrating, between France and the UK, and
their peak demand is exactly the same clock time as we have here. However, they
have a one-hour time difference. With projects like this therefore, you have to start
looking at a much wider, integrated energy system, because the real benefits of this
will come from tapping into pump storage and other storage schemes that they have,
from getting the portfolio benefit of offsetting their wind turbine down times and so on.
If we look at this more in a Europe-wide context, it becomes a much more interesting
project. In fact, somebody made the point in one of the papers that the UK is blessed
to have this tidal energy resource, but it is a global resource. There are not that
many places where you can do this, so we must view it, in assessing it, in a global
context, because the problem that it is trying to tackle is a global problem.
You need to get the promoters and developers in, to engage their interest and their
understanding of the project early. You need to get the financiers in – not just know,
because they are a little scared at the moment, but we will cultivate them. You need
the contractors and suppliers to come in – there is much upfront work that needs to
be done. You need to get the equipment manufacturers together to work in this
consortium that could deliver these bulb turbines.
It is important for the SEA and upfront studies to talk about these project structuring
and procurement issues, project financing and temporary works and so on, and the
supply chain issues that this will raise, as part of the holistic picture of looking at this
project.
Conclusions
My conclusions are that we really need to understand what we are getting into. This
is a beast that we can tame but we need to go in with our eyes open. It has
potentially profound effects on the power market – think of the surplus capacity that
you have to have to make sure that we do not have brown-outs for when the barrage
is not generating, but which is idle for some of the time. Bob talked about rewarding
those who hold that surplus capacity, and they need to be reimbursed for what they
have.
This will lead to higher prices for the consumer. You will have a system with much
greater capacity than it needs because you need to have standby capacity in there.
These rising prices represent a real test of our commitment to the Kyoto Protocol,
because you and I will have to pay more for power. I take a slightly different view on
affordability – I think that we are not the ones whom affordability is talking about, but
it is talking about the disadvantaged, the poor and the elderly who will need some
support to ensure that this does not put them in difficult situations. However, we as a
66
society have to pay more for this, and it is very simple when you look at it from a
finance point of view.
It is a challenge to the construction industry. Early engagement is important, as are
realistic expectations and careful timing is also necessary. Remember, the nuclear
plants are also coming at the same time. It is important to think about when to time
this.
We need to engage the private sector but it is very important that we do not make the
mistakes that we have made in the past. The roles of the developer need to be
distinct from those of the constructors and all the other parties that go into this, but
we have plenty of experience to do that well.
Risk should be carefully allocated: do not try to outsource problems. It is really
important – this is all of our problem, and it is not any one party’s issue. We need to
share out these problems equitably.
We should remain clear on the role of the public sector. There is no substitute for
strong leadership, in my opinion, and for sound policy. Financial support may, and
almost certainly will, be needed. EU rules may need to be challenged, both on
procurement and on things like the Habitats Directive. Instead of a project-by-project
focus, this project needs to be looked at in a bigger context – in a global context if not
a European context. It is really important that this is about this public/private
partnership.
The point I would like to leave you with is that this is not just a project but it is a
challenge for this nation. We really need to rise to the challenge if we are to take it
forward. Perhaps I sound like the politician, but it is really a challenge for the nation
and I find it terribly exciting. Thank you very much indeed.
***
67
68
DISCUSSION
Sue Ion: Thank you very much for that tour de force, Yaver. Let me invite all the
speaker to the podium and we will open the remainder of the afternoon to questions,
answers and discussion.
Not only, as Yaver pointed out, are there both amazing opportunities and challenges
there, but he has just given Sarah an even bigger challenge in that she now needs at
least another 10GW connector across to mainland Europe, to take true advantage of
this potentially global asset.
Kevin Mowbray (Welsh Energy Research Centre): I have a question for Bob. In
terms of the UK and EU carbon taxing, how is this affecting investment for your new
plant? How do you think this will affect Severn Barrage investment?
Bob Taylor: When you say EU carbon taxing, I will make the assumption that you
are talking about the Emissions Trading Scheme and the requirement to buy carbon
permits and things like that.
Kevin Mowbray: Yes, and the instability of it.
Bob Taylor: We have seen some signs that it is becoming a little more stable. The
Emissions Trading Scheme is an important part of how we look to the future when we
are assessing the choices that we make with investment. If you stand back and think
that we take long-term views of where we think the commodity prices are going for
some of the fundamental commodities, we also have to take a long-term view about
where we believe the carbon price is going as well.
In the midst of all of that, we look at various scenarios, and hence we come up with a
diverse portfolio, because there is actually no one right answer. We certainly see
some strengthening of the carbon market, which is in its second phase at the
moment. We see legislation now coming through, which should bring more certainty
through to 2020 and possibly, to a degree, up to 2025. That, plus increasing
auctioning of carbon permits from 2012 onwards, will mean that we should see a
natural strengthening. In fact, if people want to build fossil power plants, then they
may need to look at that very carefully, because you will have to buy those permits to
allow you to generate. So there should be some rewards coming through there
which give the right signals, but there is some way to go yet.
Low carbon generation is one of the ways in which the Severn Barrage could earn
some reward. However, you can see from the investment cost that it will need
probably even more than we see in the short term, that will come through from the
carbon price.
Vaughan Cole (Health and Safety Executive): I have a question for Bob. Early on
in your slides, you showed an energy gap, if you recall that.
Bob Taylor: Yes.
Vaughan Cole: In that, there is a large coal supply element, which seemed to go on
for a long time. Is it possible to look at that slide again? Perhaps you could explain
how the coal fired element is reduced.
69
The Electricity Industry faces significant challenges
y By 2020 a significant amount of the
y Capacity gap up to
25GW by 2020
UK’s existing coal and nuclear
capacity will be closed
y This equates to
over 30% of
current capacity
y A sustained investment in new
capacity is required to close the
supply demand gap
Source: E.ON UK
y New capacity will have to built in an
economic environment that is
focused on fulfilling energy policy
goals of diversity, affordability,
EU Green Package Targets for UK
20 % less carbon
emissions
compared to 1990
levels
15% of Energy in
the UK from
Renewables
20% efficiency improvement
in final energy demand
against BAU (EU wide and
non-binding)
carbon emissions reduction and
renewable energy targets
Across heat, transport and electricity
Page 2
Bob Taylor: Yes, that was to 2020. Basically, there is about 28GW of coal on the
system at the moment, in terms of capacity. The coal that will close out up to 2020 is
probably around 11GW or 12GW, or something like that. The rest of the coal, by the
way – a large amount of that we will see closing across the next decade beyond as
well.
Indeed, what you are seeing there is the capacity but what you are not seeing is the
energy generated from that capacity because, with the increasing constraints of the
Large Combustion Plant Directive, much of that capacity, even though it may have
FGD on it, will be constrained in its load factor that it can contribute. I do not know
whether I am addressing your question, but you are looking at just the next 12 years
here.
Vaughan Cole: On that slide, are you showing beyond 2015, for instance, and the
decline to 2015? Are you showing new plant?
Bob Taylor: No, sorry. All you are seeing on that slide is what happens to the
current capacity that is installed.
Vaughan Cole: Is that existing? Are you expecting –
Bob Taylor: It is not showing anything about what is built in the future. All you see
there is a number of assumptions about what happens to the current –
Vaughan Cole: So you are expecting the existing plant to go to 2020, say? Or
some existing plant?
Bob Taylor: Some of them, yes, absolutely.
Vaughan Cole: Thank you.
Professor Andrew McNaughton (Network Rail): My question is for Yaver Abidi.
You have just described the extraordinary nature of one barrage proposal. We heard
earlier about the Shoots or English Stones version, with much less power, but a
place also where, potentially, the country needs another road and rail link between
Wales and the other place. Do you have a view about the build-ability and financeability of that version of a barrage across the Severn?
70
Yaver Abidi: I can only give an outline view. I have chosen to concentrate on the
Cardiff Western scheme because it illustrates some of the issues in there. If you are
familiar with the SDC report, it argues that this project is much more do-able – and it
is. I think it is at around 1000MW, and I am not sure that it is much bigger than that.
It is certainly in the realms of having it delivered in a more traditional sense.
However, I think its impact still on the power mix in the country would mean that there
would need to be some form of support to the private sector on the continuation of
the Renewables Obligation, or if you look at the EU Carbon Trading Scheme, its
longevity. People would not necessarily enter that project without some level of
support, or some threshold that would ensure that their investment gave a due return
for the risk that they take. That is a project that is much less dramatic in its nature, I
would say, but its impact on the global issues, or on the European-wide carbon
objectives, is much less. I would say that it would just be part of the entire
renewables mix and it would not have such a dramatic impact. I chose to speak
about this one in particular for that reason.
Professor Ralph Benjamin CB (Visiting Professor, University of Bristol): I
suggest that it is unrealistic to discuss either the cost or the procurement of a
fluctuating source of energy, whether it is wind power or a tidal one, without at the
same time considering the complementary capacity to maintain the power supply at a
time when the power is less than maximum or even absent. One possible mitigation
of this problem would be if the missing power were supplied by a nuclear source
which in fact operates at full power all the time and then only part of its power is
needed. The rest could be used to generate hydrogen as a replacement – and an
environmentally-friendly replacement – for fossil fuels.
Doug Parr: There are a number of ways of approaching the supply/demand
dynamic and we focus a good deal on the supply side as the only means of doing it,
although it is not necessarily the only way of dealing with it. There are alternative
technologies, which may be small scale but they could be made larger, which could
shift peak demand.
I am not going to get into nuclear now, because I am sure that I could talk about
nuclear and you would argue back at me, and that is not the point. However,
whatever happens, it seems to me that we will have a situation where we need much
more effective supply-side management or storage of electrical power. At the
moment, I do not think the market conditions actually reflect the need to bring on the
technologies and the value in doing so. At the moment, it is very much a
supply/demand match, but the bit in the middle – both in terms of the wires and
transformers and so on, but also in terms of the balancing services – is a little
undervalued.
Hydrogen is one way of doing it but, of the options on the table at the moment, it is
quite an expensive one. Of course, it is technically do-able and we know how to do
it, so it could be done. Let me put it like this: Greenpeace used to be really
enthusiastic about the hydrogen economy but we are less so now because there are
some fundamental challenges for hydrogen storage which have not been overcome.
It is better to take a slightly more technology-blind approach to this and say that we
need better means of storing electrical power. That is a better way of approaching it
– after all, one mega-breakthrough in battery technology and the hydrogen economy
is history. So, rather than saying that we will take this particular approach to doing it,
we need a better value on the storage and management on the intermittent supply
side, so that we are better able to meet a demand which is also managed in a way
where it is not simply a case that, if anybody wants something, they just get it.
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Bob Taylor: I just want to reinforce that. When I was showing the variability on the
system, I perhaps even forgot to mention energy storage. I had three things there,
and the last one should certainly have been about energy storage. We have
announced a fairly sizeable research programme on that but, in a sense, as a sector,
we have been seduced into a lot of stuff on fuel cells and the hydrogen economy and
so forth.
In fact, one of the unsung areas, both in demand side management and storage and,
in particular, battery technology - if you think about that complementing certainly
smaller scale variable aspects of decentralised energy, then I agree.
Professor Brian Rofe (Consultant): I am addressing two points. First, Roger
pointed out the very positive aspects of the barrage and what it actually achieved in
controlling the speed of the Severn flow, and the positive answers for that. Is it
possible to put these things over because many of the objections 20 years ago were
that it would disturb the birds and that this would be a bad thing.
Just putting the opposite view, the only other alternative that has been floated by the
panel has been wind farms but, in environmental terms, these are pretty disastrous. I
am a member of RSPB and I think they are terrible. Would you like to comment?
Roger Falconer: First, if you look at the figures produced by the RSPB, the bird
populations in the Severn Estuary are relatively small. In the Ribble Estuary, for
example, which is a piddling little estuary compared to the Severn, the bird figures
are a multiplier of five greater than they are in the Severn.
The currents to which I was referring in a positive manner, if you like, are based on
computer model simulations. In terms of the loss of inter-tidal habitats and so on, we
should look more towards the possibility of two-way generation. I am only looking at
it from the fairly academic point of view of computer simulations, but there may be
construction difficulties with two-way generation and so forth. It is clearly more
complicated than Lego blocks to build the barrage.
If you went for two-way generation, you would resolve some of those problems. You
could certainly reduce the loss of inter-tidal habitats quite considerably and you could
address many of the other environmental concerns.
David Powell (Mott MacDonald): This is a question for the operator but first let me
say how much I appreciated the presentation by Yaver. I thought his cost estimate
was far more realistic and the contingency he put in there may even be an underestimate in the long-term, particularly when you look at all the logistical problems that
are involved in delivering a scheme like this.
If you were to simplify his figures – let us say that it cost £24 billion and you were
generating 8000MW, that works out roughly at £3 million per MW. I know, for
instance, that conventional hydro at this point in time costs around £500,000 per MW,
so you are talking about power which will cost six times what conventional hydro
costs.
What has not been mentioned is where wind power sits in this equation and what the
differential or relative cost would be, say, in relation to this particular project. No
matter that the price of electricity may triple, or no matter that the Carbon Trading
Scheme may influence this to some extent, you still cannot avoid that differential.
Therefore, you have to ask whether it really is viable, because there will always be
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other renewable sources of energy which will in fact be far more cost effective.
Therefore, you will never demonstrate a sensible return on the investments.
I do not know whether the operator or Yaver would like to comment further on this.
Yaver Abidi: One of the factors about tidal energy is its predictability. One of the
features of the UK power market is that the forward contracts for power are not that
long-term. This would create a different element in the mix, where we can pretty
much predict what power generation we will have in 10 years’ time on 24 November,
or whatever.
I agree that, per se, it does not stack up, but this holistic view of the entire power
market, with continental Europe as well, is necessary before we come to any
conclusion. Wind is still unpredictable: it is good as a portfolio, but you are talking
about a 10% capacity factor.
Bob Taylor: That would be during the winter peak, from the experience of our
existing portfolio, yes.
Yaver Abidi: Right, so there is 90% which is idle. It just has to be looked at in a
broader context. I am not here proposing that this project should go ahead at all, but
I just think that this seminar should be opening the debate to a wider set of issues
than purely environmental, purely cost based per unit of power, and so forth. I hope
it succeeds in doing that.
Sue Ion: I will use chairman’s prerogative to add a comment into that, against the
question that was posed. The requirement for portfolio balancing – putting all the
eggs in one basket for any type of technology - does not seem to be a very good idea
for the 21st century. Guaranteeing security of supply and having technologies in
there which have an element of guaranteed security of supply seems to be a sensible
way forward. However, we then have to recognise that they do not all cost the same
and that some cost more than others. In days gone by, we would have had a Central
Electricity Generating Board with a mix of technologies in its portfolio, which would
have taken decisions on a portfolio basis and had a mix and match. We do not have
that any longer so an open question back into the policy field is, can the market
deliver a truly balanced portfolio without further central planning and government
intervention? I offer that as an open comment.
Speaker: From the North Wales perspective, the speeches today have been very
instructive but the social element of sustainability has not been mentioned, and that
is something about which we can contribute from North Wales, having been flooded
from the coast.
Another thing that has not been mentioned is the Stern Report, which fits tidal power
as a hand fits a glove – but only when you look at it around the whole of the UK
coast. Why is it that London, for example, with the Thames, is only looking at it from
the point of view of flood defence, whereas Cardiff is only looking at it from the
perspective of energy generation? Surely, these are two complementary projects
that ought to be looked at side by side, similarly with North Wales.
Something we can offer with coastally attached tidal impoundment is the sort of
phased sequential installation of a project. You thus do not have one great big
massive project costing £200 billion all in one go – perhaps the first instalment might
cost £2 – £4 billion, and so on. Perhaps with Cardiff we should look at a coastally
attached impoundment looking at a smaller section of the coast first, rather than
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going for this massive thing that cannot be matched anywhere else around the UK.
We need to look at how projects around the UK can match each other, looking at the
tidal time incidence, and at how it can actually contribute to the baseload – not just as
a peripheral, marginal add-on extra, but actually contributing alongside nuclear in to
the baseload.
Hazel Prowse (Cathley Enterprises): My Dutch neighbour tells me that the
Netherlands is not at risk so much from the sea level rising as from high, perhaps
abnormal river flows coming down. Would high river flows from freak weather
actually be a benefit in ebb tide, or are they insignificant?
Roger Falconer: I think they are really insignificant. The flow in the Severn is
relatively small. The peak flow, 1:100 – I have forgotten the figure, but it is about
600m3/second, which is the same as the Taff. The difference between the Taff and
the Severn is that it pretty well all comes down in one go in the Taff, while in the
Severn it takes quite a long time to come down. If you look at the flow in the Severn
compared to the flux of water passing any section of the Severn Estuary, it would be
very much higher. The flow from the Severn is relatively small and sedimentation
coming down the river drops out pretty quickly. I do not see that there is a big
problem.
Perhaps I could make a comment in answer to the person who spoke from Mott
MacDonald. If we have a sea level rise of 1m to 2m, then places like Cardiff are not
very much above sea level. If we have anything like the 5m that James Hanson is
proposing might be the case, then I do not want to be alarmist but 5m would drown
out Cardiff and many other major towns along the estuary. The barrage would then
be a very feasible flood defence structure. Certainly, even at 1m to 2m, we have
major flooding problems in the estuary at the moment, or we will have.
Sue Ion: Thank you very much for that, Roger. It is my job to sum up.
First, let me thank everyone for coming this afternoon. We have had an extremely
informative afternoon which has given us, as an Academy, and also government
policy-makers, a great deal to think about. We have had excellent expositions of a
number of issues that cannot be separated out. These range from the technology
choices that we might have available to us, to the environmental and sustainability
concerns, and whether this option amongst many is one that you would put at the top
of the list; from the utility perspective, from the point of view of the huge risk and the
inability of the existing utility base to swallow the sort of risks involved without being
part of something wider, and from the project management, financing and just sheer
engineering challenges of delivering something like the project we have seen
described.
There are many questions still to come and a huge amount of analysis still to be
undertaken, and a very big challenge for government of setting it all within the
context of a total not just UK system, but European and global systems, to make sure
that the many pieces of the jigsaw all hang together to give us safe, secure supplies
of energy, going forward, and ones that enable us to enjoy the standards of living that
we have had over the last decade.
Many thanks to all the speakers – I am sure you will be able to gain access to their
presentations if you wish. I am sure that the Academy will sponsor future events of
this type to try to inform the community and take things forward. Thank you very
much indeed.
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