Small hydro from idea to operation
Survey of Potential Hydropower Sites
in the Wear and Tyne Catchments
Nick Forrest and Gordon Black
August 2010
babyHydro Ltd, Gateside Farm, Kilncadzow, Carluke, ML8 4QN
Registered in Scotland no: SC350026 VAT registration no: 970693977
Executive Summary
In March 2010 babyHydro was contracted by RENEW to quantify the remaining
hydro potential in the Wear and Tyne rainfall catchments. Hydrobot, remote hydro
modelling software owned and developed by babyHydro, was applied to the Wear
and Tyne catchments. Sites with hydro potential were analysed using multiple
iterations to optimise design, taking all costs and revenues into account. These were
analysed using an 8% per annum discount on future cashflows, and financially viable
schemes were defined as those yielding a positive Net Present Value within 20
years.
In total, 167 financially viable schemes were identified, representing an installed
capacity of 11.76MW. These were then screened by scrutinising the proposed layout
on a map, and the schemes found to be technically feasible numbered 89, with a
total installed capacity of 5.47MW.
A sample of 12 schemes was selected for further examination, and site visits were
carried out. Two more schemes were added during the site visits. For each site,
measurements were taken and observations made about favourable features and
barriers. This allowed a revised financial analysis of each site where a hydro scheme
still appeared viable. Of the 14 site evaluations, 9 suggest the sites warrant further
investigation.
The survey has demonstrated that the Wear and Tyne catchments, while not being
hydro hotspots, have a considerable number of attractive sites for development by
landowners or communities.
1
Acknowledgements
We would like to express our thanks to the following organisations, for their
cooperation and contributions to this report:
Durham City Council
Environment Agency
Forestry Commission
Natural England
NEDL
Northumberland National Park
RENEW
2
Table of Contents
Executive Summary .................................................................................................. 1
Acknowledgements ................................................................................................... 2
Table of Contents ...................................................................................................... 3
1
Introduction........................................................................................................ 4
1.1 Background ................................................................................................. 4
1.2 babyHydro, Hydrobot® and SISTech ............................................................ 4
1.3 Introduction to Hydropower .......................................................................... 4
2
Phase 1: Hydrobot® Modelling ........................................................................... 6
2.1 Methodology ................................................................................................ 6
2.1.1
Data sources ........................................................................................ 6
2.1.2
How Hydrobot® works .......................................................................... 6
2.1.3
Technical screening ............................................................................. 8
2.1.4
Shortlisting ........................................................................................... 8
2.2 Results ........................................................................................................ 9
2.2.1
Longlist ................................................................................................ 9
2.2.2
Shortlist .............................................................................................. 10
3
Phase 2: Site Evaluation .................................................................................. 11
3.1 Methodology .............................................................................................. 11
3.2 Site 2: Featherstone Castle ...................................................................... 14
3.3 Site 4: Chirdon Burn ................................................................................. 18
3.4 Site 7: Plashetts Burn ............................................................................... 21
3.5 Site 11A: Blaeberry Burn, Whitfield Estate ................................................. 24
3.6 Site 11B: Blueback Weir, Whitfield Estate .................................................. 27
3.7 Site 13: Glendue Burn, Knarlsdale Estate ................................................. 31
3.8 Site 20: Durham North ............................................................................... 34
3.9 Site 21: Durham South .............................................................................. 39
3.10 Site 22: Sunderland Bridge ........................................................................ 42
3.11 Site 25: Shittlehope Bridge ........................................................................ 44
3.12 Site 26: Eastgate Bridge ............................................................................ 46
3.13 Site 28: Craigside Caravan Park ................................................................ 50
3.14 Site 29: Stanhope Burn Caravan Park ....................................................... 54
3.15 Site 30: Swinhope Burn ............................................................................. 57
3.16 Summary of Site Evaluations ..................................................................... 62
4
Analysis and Discussion .................................................................................. 64
4.1 General Features....................................................................................... 64
4.2 Quality of Inputs and Results ..................................................................... 64
4.2.1
Elevation data and the Detailed River Network................................... 64
4.2.2
The Environment Agency’s Barriers dataset....................................... 65
4.2.3
Technical screening ........................................................................... 65
4.2.4
Site Evaluations ................................................................................. 66
5
Conclusions and Recommendations................................................................ 67
Appendix 1: Longlist of Sites Identified by Hydrobot® .............................................. 68
3
Wear and Tyne Hydropower Survey
1
Introduction
This report describes a survey of the Wear and Tyne catchments in 2010 to
identify the remaining sites with potential for a financially viable small
hydroelectric scheme. The report covers the rationale and methodology for the
study, as well as the results at two levels: a high-level, region-wide survey, and
more detailed Site Evaluations on an agreed shortlist. Following analysis of
these results, the report concludes with various options for disseminating the
information about viable sites, and assisting with their development where
appropriate.
1.1
Background
The survey was commissioned in March 2010 by RENEW, based in the Centre
For Process Innovation in Wilton, Redcar. RENEW was established in 2008 with
Regional Development Agency funding, to maximise the economic opportunities
being created by the emerging environmental industries – specifically renewable
energy and environmental sectors. RENEW’s remit is to identify business
opportunities, initiate projects and support both the development and growth of
regional businesses and inward investors.
RENEW required that the survey should review the realistic and practical
opportunities for hydro electric power within the Tyne and Wear catchments,
making recommendations on which sites showed most promise. For a shortlist of
five projects within each valley, Site Evaluations would be carried out, producing
a detailed physical and financial analysis also known as a ‘pre-feasibility study’.
These will pave the way for the investigation of other viable sites.
It is intended that this report be distributed to landowners, developers and
communities in the study area. The goal is to raise awareness of the region’s
hydroelectric potential, and to facilitate the development of projects through to
installation.
1.2
babyHydro, Hydrobot® and SISTech
The contract to undertake this survey was awarded to babyHydro Ltd,
established in 2008 to take micro-hydro projects from initial concept through to
generation of renewable electricity. babyHydro supports landowners and
developers through every stage of creating electricity from running water.
babyHydro owns and has exclusive use of Hydrobot® remote hydro surveying
software. Hydrobot® is a geographical and hydrological computer model
developed in 2006 to remotely predict financially viable hydroelectric schemes
across large areas. The model has been used twice to survey the whole of
Scotland for the Scottish Government.
SISTech (the Scottish Institute for Sustainable Technology) is a research
consultancy experienced in sustainable development, including carbon and
environmental assessment and working with extensive GIS datasets. In this
survey, SISTech provided support in obtaining field data, contact with
landowners and additional GIS analysis.
1.3
Introduction to Hydropower
As this report refers in detail to why one particular hydro scheme might be better
than another, a brief description of hydropower is necessary. A hydro scheme
4
Wear and Tyne Hydropower Survey
comprises a system for extracting energy from water as it moves, normally
dropping from one elevation to another. The uppermost part of a hydro scheme
is therefore the intake, and a weir is typically used to ensure the water remains
deep enough to cover the intake. In some cases, such as above a small
waterfall, a natural pool will suffice but it is uncommon to find a site that does not
require an impoundment structure.
Water that is restricted in a sloping pipe (or penstock) will build up a head of
pressure at the bottom, which can be used to drive a turbine wheel (or runner).
In flatter areas where there is less pressure build-up or no penstock at all, much
larger flows are required to compensate for the reduced head, and so larger
turbines are used.
In addition to flow and head, a destination or load for the power is needed. In this
study, the load is the national grid. As connection and the cost of lines are
significant parts of most schemes, distance from the grid may be the deciding
factor of whether a scheme is viable. Furthermore, the grid operator must take
into account the capacity of the local grid before allowing a scheme to connect.
Not all water within a river can be used for generation – a proportion called the
“reserve flow” must be left within the river for ecological reasons. Unless there is
a storage dam, the usable flow will fluctuate throughout the year, and the
system’s efficiency will vary as a result. Different turbines have different
responses to variations in flow, and this must be taken into account when
predicting the available energy.
Finally, for any hydro scheme there are usually a number of layouts and sizes
that could be used. Finding the best solution is a matter of experience and
costing out the various options. As Hydrobot® carries out multiple iterations to
evaluate a large number of layouts for each site, it mimics the approach of an
engineer in the flesh, so is ideally suited to this survey.
The methodologies and results are grouped into two sections to reflect the two
phases of the survey: the desk-based survey of both valleys using Hydrobot®,
followed by physical site visits. Analysis and Discussion is presented as one
section, followed by Conclusions and Recommendations.
5
Wear and Tyne Hydropower Survey
2
Phase 1: Hydrobot® Modelling
This section of the report explains how the desk-based survey of the whole of
the Wear and Tyne catchments was undertaken, producing the list of remaining
financially viable hydro sites. Data sources are described, as well as the basic
approach of the Hydrobot® software. Subsequent treatment of the results is also
explained, followed by the results themselves: a longlist of all financially and
technically viable sites; and a shortlist of sites for more detailed examination.
2.1
Methodology
2.1.1
Data sources
Ordnance Survey provided elevation and contour datasets, as well as building
and settlement locations that were used to identify potential grid connections at
low voltage and 11kV. In addition, roads, railways and existing lakes were
identified using Ordnance Survey data. The 20kV and 30kV distribution networks
were mapped using information from NEDL.
Flow duration curves for gauging stations across the region from the National
River Flow Archive were obtained from the Centre for Ecology and Hydrology.
The Environment Agency provided information on gauged weirs, but also data
on ‘barriers’ identified in their recent report ‘Opportunity and Environmental
Sensitivity Mapping for Hydropower in England and Wales’1
Electronic mapping of environmentally sensitive areas were obtained from
Natural England, with advice on the relative sensitivity and necessary mitigations
coming from both Natural England and the Environment Agency. Existing hydro
schemes were plotted using information from the British Hydropower Association
and prior knowledge. Land ownership was established from a variety of sources
including the Forestry Commission, Durham County Council, the Land Registry
and local knowledge.
Other information such as costs, energy production and impacts of
environmental sensitivities or other barriers, were previously incorporated into
Hydrobot® and are described in the Scottish Hydropower Resource Study2.
2.1.2
How Hydrobot® works
In analysing a river basin, Hydrobot® operates as follows:
1. River courses and the flow duration curve at each point on every
watercourse are modelled across the river basin.
2. Watercourses affected by existing hydro schemes or other licensed
abstractions are removed from subsequent calculations.
3. Likely river reaches for high-head turbines are selected, and turbines
are initially positioned at the foot of such reaches. Nearest gridconnections are located at as many voltage levels as exist within that
river basin.
1
2
Environment Agency, Mapping Hydropower Opportunities and Sensitivities in England and Wales, February 2010.
Nick Forrest Associates Ltd et al, Scottish Hydropower Resource Study, August 2008
6
Wear and Tyne Hydropower Survey
4. A range of penstock lengths from 20m to 1500m are simulated. For
each length, turbine and other elements are sized appropriately using
industry standards.
5. Each configuration is evaluated using cost formulae for each element,
and the lifetime energy and revenue are calculated based on the flow
duration curve. This leads to selection of the “best” solution.
6. Steps 4 and 5 are repeated with each turbine 20m upstream, then 20m
again, until no better solution is found for that site.
7. Nearby schemes are tested to see whether they would be better joined
into one large scheme or kept as separate ones.
8. Weirs registered under the Controlled Activities Regulations are tested
for low-head hydro potential, similar to high-head but without the
penstock.
Input parameters can be varied to suit current economic conditions and policy
changes. Such parameters were not the main focus of this study so were
maintained at the following levels:
•
Recovery period: schemes were deemed viable if they broke even
within 20 years, including interest, taxes, etc. A typical hydro scheme
should keep generating for well over 30 years, with a turbine overhaul at
some stage after 20 years.
•
Business rates: £9/kW per year.
•
Railway crossing ransom charge: 33% of NPV payable to rail company
for penstocks crossing under a railway (based on case history in
Scotland).
•
Environmental constraints: environmental designations were split into
three levels of severity, relating to the level of protection they entail.
Special Areas of Conservation and Special Protection Areas will
generally require thorough investigation beforehand, and the cost of the
additional environmental surveys can be roughly estimated from the
scheme size. SSSIs, Nature Reserves and National Parks will entail
some extra surveying, and therefore costs, but not as much. Schemes
on salmon migratory routes will not only require an additional survey but
also mitigation measures, in particular a fish ladder whose cost can be
related to the total height of the ladder and the flow.
•
Grid constraints: as this report is taking the long-term view of hydro
growth, it may be assumed that planned upgrades to the transmission
and distribution grid will relieve the principal current bottlenecks in grid
connection approvals. Therefore the only grid constraints taken into
account are typical ratings of the lines and existing transformers to
which schemes are connecting. Costs for upgrades to the network were
found to be comparable to those in Scotland, and are included in the
model.
Table 1 below outlines the Feed-in Tariff levels implemented in the Hydrobot®
model. These have been transcribed directly from the UK government’s
response to its Summer 2009 consultation3. The tariff comprises an amount paid
per unit generated whether used onsite or not (the Feed-In Tariff element) and a
3
DECC (2010). Feed-In Tariffs: Government’s Response to the Summer 2009 Consultation.
7
Wear and Tyne Hydropower Survey
guaranteed minimum price for each unit exported to the grid (the export
revenue).
Table 1. Feed-In Tariff levels announced by UK Government.
Installed Capacity
Feed-in
(p/kWh)
≤15 kW
15 kW – 100 kW
100 kW – 2 MW
2 MW – 5 MW
19.9
17.8
11.0
4.5
Tariff Export
(p/kWh)
3.0
3.0
3.0
3.0
Revenue Total
Revenue
assuming
100%
export (p/kWh)
22.9
20.8
14.0
7.5
Finally the threshold for financial viability was set as positive Net Present Value
after 20 years, discounting cashflows at 8% per annum. This is equivalent to an
8% Internal Rate of Return over 20 years. This discount rate would previously
have been too high for many domestic-scale schemes, but with the Feed-In
Tariffs, good domestic schemes will still be financially viable.
2.1.3
Technical screening
Hydrobot® optimises each scheme according to the topographic, flow and other
data available as described above, taking into account various barriers and
problems. However, there are some factors that can inhibit a hydro scheme but
may not show up in the input data. These include but are not restricted to:
•
Gorges which do not have any flatter points along their banks, thus
making it too difficult to run a pipe along the contour;
•
Roads, or groups of roads, which would be too expensive to cross
compared to the potential value of the resulting hydro scheme;
•
Houses, schools or other non-industrial buildings blocking the pipe route;
•
Disagreement between the Environment Agency’s Detailed River
Network and Ordnance Survey’s elevation data, giving the impression of
sudden drops in the river where none exist;
•
Errors in the Environment Agency’s barriers dataset, suggesting there is
a weir or waterfall where none exists.
Some of these can be detected fairly easily. Others require experience of hydro
development to assess the technical feasibility of a site by careful reference to
maps on a variety of scales. For this reason, a technical screening was
conducted on all financially viable projects identified. In some cases a small
adjustment to Hydrobot’s suggested layout is required, and such notes were
included in the results. Rejected solutions were grouped into three categories:
gorges, false positives, and other barriers, should anyone wish in the future to
establish why their site of interest might have been rejected.
It should be noted that a range of solutions normally exists for any engineering
problem, so there is an element of subjectivity in the technical screening. A
different hydro engineer could arrive at a different conclusion for a site based, for
example, on local knowledge or new technology.
2.1.4
Shortlisting
It was agreed that the Site Evaluations should be carried out on sites with a
reasonable chance of successful development, so that they would be worthwhile
8
Wear and Tyne Hydropower Survey
examples to future developers. To this end, the longlist of solutions remaining
after technical screening were ranked by the cost of energy, calculated as:
Cost of energy (£/MWh) = Capital cost (£) / Annual energy (MWh)
Twelve sites from the two river basins were selected with a low cost of energy,
and with a mixture of high-head (hillsides) and low-head sites (weirs or other
barriers). This was to allow for up to two sites being deemed unsuitable upon
arrival, leaving ten Site Evaluations.
For these twelve sites, land ownership was established by various methods:
•
The Forestry Commission provided data showing areas they manage
•
The Land Registry
•
Northumberland National Park
•
Durham County Council
•
Contacting local hotels, pubs, campsites etc.
Where possible, landowners were contacted and permission was obtained to
access their land in order to carry out the Site Evaluations.
2.2
Results
This section describes the results from Hydrobot’s region-wide survey of the
Wear and Tyne Catchments. Following the National River Flow Archive’s naming
convention, the Tyne river basin is referred to as c23, and the Wear is c24.
Applying the model to both catchments 1,502 sites were examined. Of these,
167 showed a positive Net Present Value within 20 years, discounting future
cashflows at 8% per annum, and so were deemed financially viable. They
represent a total installed power of 11.76MW. The split between catchments can
be seen in Table 2.
Table 2. Results of Hydrobot’s region-wide survey for Tyne (c23) and Wear catchments (c24). Results
show total number of sites examined; viable projects with a positive NPV after 20 years; projects
longlisted after technical screening; and a breakdown of the longlist by installed power of scheme, in the
size categories devised for the FITs tariff levels.
River
basin
Number of
sites
examined
Financially
viable
projects
Financially Technically Technically
viable
viable
viable power
power (kW)
projects
(kW)
Count
0kW to
15kW
Count
Count
15kW to 100kW to
100kW
2MW
c23
1,150
131
8,398
65
2,781
11
52
2
c24
352
36
3,361
24
2,688
0
15
9
1,502
167
11,760
89
5,469
11
67
11
Total
2.2.1
Longlist
Technical screening removed almost half of the projects, leaving 65 in c23 and
24 in c24 – a total of 89 projects in the longlist. Their total installed power is then
9
Wear and Tyne Hydropower Survey
5.47MW. The majority of schemes for both river basins are in the range 15kW to
100kW.
The full list of financially and technically viable projects can be found in
Appendix 1.
2.2.2
Shortlist
The shortlisted sites are listed in Table 3, with some headline figures for each.
The third digit of the turbine number indicates which projects are high-head (a
pipe or ‘penstock’ running down a hillside to a turbine) and which are low-head
(a weir, waterfall or other short drop that presents a barrier to fish passage): 0
indicates high-head while 1 indicates low-head.
Table 3. Shortlisted sites selected for Site Evaluations. There are five schemes in the Tyne catchment
(c23) and seven in the Wear catchment (c24). Only one scheme in c23 was low-head (i.e. a weir or
waterfall), and four of the seven in c24 were low-head. The table lists the installed capacity or design
power; flow and head; capital cost and annual net revenue (including FITs, net of operating costs); the
discounted Net Present Value; and the simple payback (not including inflation or loan interest).
River
basin
c23
c23
c23
c23
c23
c24
c24
c24
c24
c24
c24
c24
Turbine
number
23000342
23001706
23001999
23002486
23100355
24000215
24000659
24000974
24100128
24100137
24100177
24100186
Installed
power
(kW)
91
200
86
67
83
129
169
221
118
534
127
342
Design
flow
(m3/s)
0.208
0.910
0.128
0.129
10.799
0.270
0.522
0.961
4.240
14.737
5.170
11.377
Net
Head Capital cost revenue
(m)
(£)
(£/Yr)
57
479,767
74,616
28
869,317
97,800
88
375,459
69,485
68
345,011
53,484
1
407,878
63,911
62
532,164
62,829
41
566,709
76,895
29
832,271
98,542
4
473,933
57,986
5 1,538,450 243,961
3
515,353
62,022
4
962,324 164,896
10
NPV
discounted
8% (£)
252,822
90,902
306,753
180,104
219,610
84,700
188,257
135,228
95,379
856,794
93,583
656,648
Simple
payback
(years)
6
9
5
6
6
8
7
8
8
6
8
6
Wear and Tyne Hydropower Survey
3
Phase 2: Site Evaluation
This section contains a description of the site visits carried out for each of the
shortlisted sites, with a summary of the key findings for each. These Site
Evaluations include an assessment of the potential for practical and
commercially viable development.
3.1
Methodology
The sites from which the shortlist was drawn had been renumbered using shorter
numbers for convenience, as shown in Table 4. Two extra sites were added
during the course of the Site Evaluations: 11B (which had not been identified by
Hydrobot®) and 21.
Table 4. Numbering of sites visited during the Site Evaluations. Hydrobot’s initial
prediction of the potential power is also given.
Site Number
Turbine
Initial
Number
Power (kW)
2
23100355
83
4
23001706
200
7
23000342
91
11A
23002486
67
11B
-
13
23001999
86
20
24100137
534
21
24100081
266
22
24100186
342
25
24100177
127
26
24100128
118
28
24000974
221
29
24000659
169
30
24000215
129
The locations of the various sites are shown in Figure 1.
11
Wear and Tyne Hydropower Survey
7
4
2
13
11A
&B
20
28
30
21
25
26
22
Figure 1. Map of site locations visited for Site Evaluations. © Crown copyright 2010.
License number 100049709.
The process by which a potential scheme was evaluated through a site visit had
a core structure which was modified in response to circumstances on the day,
physical access routes and the topography of the area.
The core structure was as follows:
1. Examine Hydrobot® information and from the map assess the location of
the key features (turbine house, abstraction point and most probable
route of penstock) and create plan for the site visit incorporating access,
restrictions and potential risks.
2. Meet on site with the landowner or their representative for general
orientation and recommendations on access routes and restrictions, for
example neighbours.
3. Examine the Hydrobot® identified location of the turbine house and
explore upstream and downstream on both banks to generate a set of
options considering the aspects of security from flooding, tailrace, visual
impact and engineering access.
4. Determine the most likely incoming route for the penstock.
5. Walk the route of the most probable penstock line establishing nature of
the terrain (steepness and rock versus soil) and engineering access.
12
Wear and Tyne Hydropower Survey
6. Examine the Hydrobot® identified location of the abstraction point plus
other options upstream and downstream, along with the location implied
by the optimum route of penstock. The key features for assessment are;
secure location for the weir, impact of water back-up and potential risk of
bank flooding, physical structure of the abstraction point given the nature
of the river bed, banks, local terrain and engineering access.
7. Determine the options available for initial run of the penstock to enable
the route to be separated from the river course as early as possible to
maximise route flexibility.
8. Revisit the location(s) of the turbine house and determine the options
available for interconnection with the Electrical Distribution Network.
Throughout the process environmental aspects and implications were noted, and
photographs taken to record all of the key features. For each site visited, general
information about the site is provided below, along with more technical
observations and headline figures.
13
Wear and Tyne Hydropower Survey
3.2
Site 2: Featherstone Castle
Observations:
The site comprises a weir with an existing fish pool. This scheme would have to
be developed in close collaboration with the EA due to the nature of the works
that would be required on either bank, or on the weir itself, coupled with the fact
that there is a Flow Gauging Station incorporated.
It is recommended that the ownership be identified (most likely The Environment
Agency, or possibly Featherstone Castle) and an exploratory conversation held.
Location:
Singe-phase
power line
Figure 2. Map of Site 2. Red dot marks position of turbine. Single-phase overhead power line
shown at farm and running across the park (orange). © Crown copyright 2010. License
number 100049709.
14
Wear and Tyne Hydropower Survey
Scheme Layout:
Steep
slope
OPTION B
OPTION A
Fish-pass
Pool
OPTION C
Flow
Gauging
Station
Dry
Flow
Bank –
flat &
2.5m
above
river level
Bank –
flat & 3m
above
river level
Figure 3. Illustration of scheme layout for Site 2. Three options for positioning the turbine are illustrated,
and explained below.
Scheme Options:
There are three physical layout options all of which have significant negative
aspects.
Option A: This would require a channel to be cut around the Flow Gauging
Station to a depth of approximately 4m, a concrete pipe to be inserted, and then
the ground backfilled. A critical issue at construction stage would be maintaining
the structural integrity of the buttress and the FGS. The turbine employed could
be either an Archimedes screw or a Kaplan. The key issue would be gaining
sufficient elevation to keep the generator above the flood level. Equipment
access is excellent. This is the preferred option.
Option B: Similar to the above but on the left bank. Access for construction
machinery would be very difficult – no access track, soft ground, and a steep
slope to fields at the top.
Option C: A Kaplan turbine could be placed on the weir itself and the solid
bedrock just below it. The turbine would be placed vertically to enable the
generator and control instrumentation to be raised above the flood level. This
15
Wear and Tyne Hydropower Survey
scheme option is likely to be considered by the EA to cause a restriction on river
flow. Again, engineering access would be very difficult.
Figure 4. Featherstone Castle weir looking upstream. Fish pass pool
in foreground.
Flow and Power Analysis:
The design flow (Qdes) modelled by Hydrobot® was 10.25m3/s. Given the
structure of the fishpass the available flow is likely to be less than this. There is
a 25mm difference in the heights of the two sections of weir, with the dry being
28m wide and the wet being 14m wide. This results in a substantial body of
water flowing down the fishpass. Visual inspection suggests that this is
significantly in excess of Q95, the normal reserve flow.
The gross head was observed as 1.3m. Assuming a reserve flow of Q80 (2m3/s),
the output power would be as reported below in Key Numbers.
Electrical Distribution Network Interconnection:
There is a single phase supply to the farmhouse shown on the map, and a single
phase supply running across the park, again, shown on the map.
Environmental Observations:
Based on initial discussions, the EA is not opposed in principle to works on
weirs, providing the developer demonstrates the continuity of their
measurements at the FGS. The scheme should not affect flow measurements
significantly, and EA has expressed support for low-head schemes.
16
Wear and Tyne Hydropower Survey
Figure 5. Featherstone Castle weir looking downstream.
Gauging station visible to far right.
Conclusion: Site valid.
Key Numbers:
Site Name
2 - Featherstone Castle
Installed
Head (m) power (kW)
1.3
99
Initial
cost
£398,054
17
Annual
cost
£4,597
Annual
gross
revenue
£75,365
Simple
payback
(years)
5.6
20 year
simple
profit
£1,017,308
Wear and Tyne Hydropower Survey
3.3
Site 4: Chirdon Burn
Observations:
The site is on Forestry Commission land. Hydrobot® had identified the optimum
scheme as having a head of 28m but inspection revealed the practical head to
be 13m based on Jerry’s Linn waterfall. The land upstream of this was almost
level right up to Hydrobot’s preferred abstraction point.
Scheme Layout:
Figure 6. Map of Site 4. Red line indicates penstock route; red dot indicates turbine site.
© Crown copyright 2010. License number 100049709.
18
Wear and Tyne Hydropower Survey
Abstraction Point:
The selected abstraction point is immediately above Jerry’s Linn on top of a solid
rock base. There is a risk however that a one metre high weir could cause
significant backing up of the water causing it to overspill onto the surrounding flat
land.
Figure 7. Upstream view of Jerry’s Linn showing the flat land above it,
and the nature of the difficult terrain/rockface on the left bank where
the penstock would run.
Figure 8. Site of the abstraction point immediately above the waterfall
- river flowing from left to right.
19
Wear and Tyne Hydropower Survey
Route of Penstock:
The penstock would have to be routed around the rockface on the southern
bank. This is not quite vertical and with a drop of some 5m, but it is fragmented
and is likely to be an expensive engineering challenge.
Turbine & Generator:
The turbine house would be located just outside of the field close to the burn. A
second option would be to locate it a little further downstream at the footbridge
and thus gain a few extra metres of head at the expense of 300m or so of
additional penstock run.
Electrical Distribution Network Interconnection:
The nearest point of interconnection to overhead single phase is some 2km
distant at Bower near the end of the public roadway. The majority of the
transmission line could be routed over open fields but some would have to go
through the forest.
Engineering Access:
Access to all points is good – trees in the surrounding area have recently been
harvested.
Environmental Observations:
Jerry’s Linn presents an impassable barrier to migratory fish.
Conclusion:
Engineering challenges too great for this head and size of scheme. Not valid.
20
Wear and Tyne Hydropower Survey
3.4
Site 7: Plashetts Burn
Observations:
The site is on Forestry Commission land, and would be a high-head scheme
running from near Wainhope to a point approximately 1km downstream.
Hydrobot’s identified intake and turbine locations were found to be optimal.
Scheme Layout:
3-phase overhead line
Figure 9. Map of Site 7. © Crown copyright 2010. License number
100049709.
Abstraction Point:
The abstraction point is confirmed as being just downstream from the field. The
ground is fairly flat and peaty, therefore soft, making access possibly difficult for
the last few metres, though there are several possibilities for the location of the
weir. The forest track provides excellent access on the approach.
Route of Penstock:
It appears to be possible to transport the water by means of low pressure pipe
above the 260m contour all the way around the escarpment to a point close to
the forest rack just below the digit ‘2’ of the turbine number. Here it would enter
a forebay before being run down the steep bank to the turbine house.
Some of the route of the low pressure pipe would be through a young plantation,
therefore passable.
21
Wear and Tyne Hydropower Survey
Turbine & Generator:
The turbine house would be located on a flat but raise area of ground adjacent to
the burn.
Figure 10. Photo taken from the site of the turbine house
looking up the probable access and penstock routes.
Electrical Distribution Network Interconnection:
There is a 3-Phase overhead power line some 700m from the turbine house site.
Engineering Access:
Access to the turbine house would require 100m of new track to be created
running from the forest track in a north-westerly direction down the steep bank at
an angle – difficult, but achievable.
Potential Enhancement:
A modification to the scheme would be to locate the turbine house adjacent to
the track bridge downstream. This would result in an additional 20m of head but
would require the penstock to be extended. The revised location would make for
easier access for construction of the turbine house, and the routing of the
penstock would be down a gentler gradient. The turbine house would also be
closer to the power lines.
Conclusion: Site valid.
22
Wear and Tyne Hydropower Survey
Key Numbers:
Site Name
7 - Plashetts Burn
Head (m)
57
Installed
power (kW)
86
7 - Plashetts Burn extended
77
100
Annual gross
Initial cost Annual cost
revenue
£430,151
£4,941
£72,973
£373,919
23
£4,332
£90,767
Simple
payback
(years)
6.3
4.3
20 year
simple profit
£930,485
£1,354,784
Wear and Tyne Hydropower Survey
3.5
Site 11A: Blaeberry Burn, Whitfield Estate
Observations:
The Blaeburry Burn scheme would be high-head, but is in a slight gorge. This
scheme is very unlikely to be viable due to almost every aspect presenting a
difficulty.
Scheme Layout:
Figure 11. Map of Site 11A. © Crown copyright 2010. License number
100049709.
Abstraction Point:
The forest shown on the map is in fact extremely dense and impassable.
Additionally, from inspection on the hillside, the river is in a slight gorge.
A potential abstraction point was identified slightly downstream of that indicated
on the map. This would result in the head being reduced by approximately 20m.
Route of Penstock:
The penstock would be routed on the northern bank (photo below) – but would
be required to cross two tributaries.
24
Wear and Tyne Hydropower Survey
Figure 12. Route of penstock for Site 11A.
Turbine & Generator:
A flat and flood secure zone was identified for the turbine house. A new access
track would be required coming in from the hill fields to the west.
Figure 13. Turbine house location for Site 11A.
Electrical Distribution Network Interconnection:
Connection to single phase O/H supply could be made at either Park Head Farm
or Mainsrigg – both at about 500m.
25
Wear and Tyne Hydropower Survey
Conclusion:
The site is valid with a modified layout.
Key Numbers:
Site Name
11A - Blaeberry Burn
Head (m)
Installed
power (kW)
35
33
Annual gross
Initial cost Annual cost
revenue
£309,135
26
£3,558
£26,952
Simple
payback
(years)
13.2
20 year
simple profit
£158,744
Wear and Tyne Hydropower Survey
3.6
Site 11B: Blueback Weir, Whitfield Estate
Observations:
This is a practical scheme based on a derelict weir located by the EA, but whose
height was underestimated at 1m, where it is actually 3.5m.
Location:
The weir is shown in the exact centre of the map.
Figure 14. Map of Site 11B. © Crown copyright 2010. License number
100049709.
27
Wear and Tyne Hydropower Survey
Scheme Layout:
Direction of
flow
Proposed inlet
channel
Existing
sluice
Wall
10m
Old
workings
and site
of village
hydro
Original
water
power
channel
Archimedes
screw
Turbine
House
Figure 15. Layout at Site 11B.
28
R
o
a
d
Wear and Tyne Hydropower Survey
Photos:
Figure 16. Blueback weir looking across to old wheelhouse.
Figure 17. Existing Village Hall micro-hydro scheme intake.
Abstraction Point:
The abstraction would be made on the left bank where the land is only 1.5m
above the surface of the water.
Turbine & Generator:
An Archimedes screw or Kaplan turbine could be employed.
29
Wear and Tyne Hydropower Survey
Figure 18. Site of Archimedes screw looking down to the river below the weir
Electrical Distribution Network Interconnection:
There is a single phase O/H powerline some 200m to the west across an open
field.
Engineering Access:
There is an access track leading from the public road right down to the water
some 100m upstream. This leads to a ford which has been used for riverbed
managements (shifting stones in evidence).
Environmental Observations:
The weir appears sound and almost watertight. Some repairs will be required.
Conclusion: Scheme valid.
Key Numbers:
Site Name
11B - Blueback Weir
Head (m)
Installed
power (kW)
3.5
48
Annual gross
Initial cost Annual cost
revenue
£234,195
30
£2,752
£38,369
Simple
payback
(years)
6.6
20 year
simple profit
£478,140
Wear and Tyne Hydropower Survey
3.7
Site 13: Glendue Burn, Knarlsdale Estate
Observations:
This high-head scheme is required to cross under the A689 – a layout that is
unlikely to be viable due to the limited space within the bridge infrastructure. The
landowner was not identified, and therefore permission to survey the site not
achieved. Furthermore, there is evidence of historic abstraction to the north,
which might affect the viability of a hydro scheme here.
Scheme Layout:
Figure 19. Map of Site 13. © Crown copyright 2010. License number
100049709.
Abstraction Point:
The abstraction point was not identified, but from the hillside the burn appeared
to be in a very narrow gorge – which was partially obscured by trees.
31
Wear and Tyne Hydropower Survey
Figure 20. Looking up the glen towards the proposed location of the
abstraction point.
Figure 21. River flowing towards the bridge.
Route of Penstock:
The penstock would be required to cross under the road. The construction of a
dedicated pipe route would be expensive since the works would have to be
carried out by Northumberland Council Transport Department. The alternative
32
Wear and Tyne Hydropower Survey
would be to secure the penstock to the side wall of the existing river channel
under the road. This is likely to be considered by Northumberland Council
Transport Department as unacceptable as it would cause a reduction in the
space available for floodwater – which is already observably restricted. The
dimensions of the culvert are 1.25m by 1.25m. This is likely to be exacerbated
by the recent planting of new deciduous trees in the glen.
Figure 22. Looking upstream from the culvert – clear evidence of
moving rocks.
Turbine & Generator:
The site identified by Hydrobot® for the turbine house is in a densely forested
area. Close inspection was not possible.
Conclusion:
Engineering challenges too great for this size of scheme. Not valid.
33
Wear and Tyne Hydropower Survey
3.8
Site 20: Durham North
Observations:
This scheme is misplaced on the jpeg. The weir is shown on the map adjacent
to the Castle, but in fact extends further downstream. The weir stretches some
57m across the river and arcs some 196 along the course of the river. With a
gross head of 2.5m and a Qdes of 14.7 the power potential is 257kW. An
excellent site exists for the location of the turbine – with no intervention required
on the weir.
Scheme Location:
Extent of
the weir
Turbine
Figure 23. Map of Site 20. © Crown copyright 2010. License
number 100049709.
Description of the Weir:
The main weir consists of an arc spanning some 57m across the river and
running 237m downstream to reach a system of sluice gates on the east bank.
There is a fish pass on the west bank of the main weir. Below the main weir
there are three lower weirs, each with a fish pass. The available gross head
from the main weir to the level below the sluice gate (but still above the lower
weir) was visually estimated at 2.5m. The lowest weir could provide an
additional head of 0.5m.
34
Wear and Tyne Hydropower Survey
Figure 24. Durham weir looking downstream from right to left. Top fish ladder visible just
beyond ducks. Turbine location in upper left of photo where white water visible beyond
bridge.
Turbine Location:
There is an ideal site for the turbine and generator etc at the existing sluice gate
workings. The workings show evidence of recent partial refurbishment making
them sound and presenting a 1m wide by 1m deep sluice gate. It is proposed
that a turbine (Archimedes screw or Kaplan) be installed using the sluice gate as
an inlet and discharging on to the gravel bed below. This would avoid any
engineering works having to be carried out on the weir itself, plus avoiding any
impact on the existing fish-passes other than flow reduction, which would be
managed. This would result in a small scheme with reduced power output and
costs. For the full potential to be achieved significant restructuring of the sluice
workings would be required.
35
Wear and Tyne Hydropower Survey
East bank
Wall
River
Flow
Pebble
shore
Secondary
sluice gate
Public
Road
Primary
sluice gate
Walkway
Turbine
Existing
Trash
Screen
Lower
water
level
Upper
Water
level
Weir
Figure 25. Illustration of sluice gate area and proposed hydropower infrastructure – not to scale.
36
Wear and Tyne Hydropower Survey
Ice rink
Lower weir
Pebble shore
Target sluice gate
Figure 26. Turbine site between lowest extremity of upper weir (on right of photo), and lower weir
downstream.
Figure 27. Target sluice gate.
37
Wear and Tyne Hydropower Survey
Electrical Distribution Network Interconnection:
It is anticipated that there will be a 3-phase supply to the redundant icerink/bowling centre 100m downstream on the east bank.
Engineering Access:
Access is excellent. Subject to permissions the removal of a wooden fence and
a tree is all that would be required. Heavy equipment could be craned over the
wall separating the site from the public road.
Environmental Observations:
The key environmental issue is the maintenance of sufficient water flow through
the fish-passes
There is the option to extend the scheme further down the east bank and
discharge below the bottom weir. This would provide an additional 0.5m head
and take the output power to 308kW, but would require significant engineering
and the development of a supply channel along the bank.
Key Numbers:
Site Name
20 - Durham
Head (m)
Installed
power (kW)
2.5
221
Annual gross
Initial cost Annual cost
revenue
£876,299
38
£9,917
£131,161
Simple
payback
(years)
7.2
20 year
simple profit
£1,548,585
Wear and Tyne Hydropower Survey
3.9
Site 21: Durham South
Observations:
This weir is situated slightly south of Site 20, though the EA dataset indicated
that it was slightly further south.
The weir is shown on the map adjacent to the Cathedral. However, the original
mill buildings are still in place on either bank with sluices and channels still
carrying water. There might have been an opportunity for the development of
two small schemes to be placed within the existing historical infrastructure. While
the EA dataset suggested the head was considerably more, the gross head is
only around 0.4m. The theoretical power potential is 33kW, but in practice this
head is not sufficient for a practical hydro scheme.
Scheme Location
Weir
Figure 28. Map of Site 21. © Crown copyright 2010. License
number 100049709.
39
Wear and Tyne Hydropower Survey
Photos:
Figure 29: Durham weir from the west bank looking towards the mill museum and the
Cathedral above.
Figure 30. View from downstream showing tailrace.
Conclusion:
40
Wear and Tyne Hydropower Survey
While there is infrastructure from historical use of the weir for driving mill
equipment, the head is too low to be practical for electricity generation. Not
viable.
41
Wear and Tyne Hydropower Survey
3.10
Site 22: Sunderland Bridge
Observations:
This site was indicated by the EA dataset and the height of the weir was
estimated by Hydrobot® to be over 3m. However, this is an error due to the
presence of two wide bridges. There is a ‘weir’ of some 300mm under the older
bridge and integral to its foundations. There is a line of large stones across the
river at the site of the original bridge (evidenced by the pier on the north bank)
but these are not dressed and therefore are not part of the original bridge nor an
earlier weir. The estimated head across these stones is 750mm.
There was no visual evidence of other weirs upstream or downstream.
Location:
Figure 31. Map of Site 22. © Crown copyright 2010. License number 100049709.
42
Wear and Tyne Hydropower Survey
Photographs:
Figure 32. Bridge and ‘weir’ looking upstream.
Figure 33. Zone of stones producing 750mm level difference.
It would be a major engineering task to create a new weir and given the
presence of the original bridge (archaeological interest), the old bridge in the
photograph and the risk of flooding, it is inconceivable that planning permission
would be granted for a scheme that would be producing only 50kW.
Conclusion:
Insufficient head and archaeological obstacles. Not viable.
43
Wear and Tyne Hydropower Survey
3.11
Site 25: Shittlehope Bridge
Observations:
The site was identified by the Environment Agency as being on the River Wear
close to the road bridge downstream from Stanhope. However, during
inspection the reported 3.2 metre weir was discovered to be not on the main
river course but on a tributary on the north bank a few metres downstream from
the bridge.
Location:
Figure 34: Map of Site 25 showing the predicted location of the weir of interest as a red
dot. The actual location was on the tributary to the north. © Crown copyright 2010.
License number 100049709.
44
Wear and Tyne Hydropower Survey
Photographs:
Figure 35: Photo of the bridge looking upstream
Figure 36: Weir discovered on the minor tributary
Conclusion:
Actual location of weir has very small flow. Not viable.
45
Wear and Tyne Hydropower Survey
3.12
Site 26: Eastgate Bridge
Observations:
The potential scheme is on the River Wear downstream from Eastgate and
adjacent to the road bridge. The weir would require extensive reconstruction.
Location:
Figure 37: Map showing the location of the scheme – marked by the red dot on the
main river. © Crown copyright 2010. License number 100049709.
Scheme Layout:
46
Wear and Tyne Hydropower Survey
Archimedes
screw
Bridge
stonework
Intake
Road Bridge
River flow
Fish-pass
Figure 38: Layout of the weir and the site of the potential turbine.
Photos:
Figure 39: Photo taken looking upstream showing the fishpass in the centre of the weir.
47
Wear and Tyne Hydropower Survey
Figure 40. Erosion on weir face.
Figure 41: Proposed turbine location is in centre of photograph
Electrical Distribution Network Interconnection:
There is a 3-phase overhead powerline some 50m to the south.
Conclusion:
While there is a practical location for a turbine the scheme is unlikely to be viable
due to the low head (1.3m) providing 36kW, and the poor condition of the weir
(which would require extensive reconstruction). However, it is still possible if
upgrades to the weir were planned anyway. As the weir is unsafe in its present
condition, an upgrade would seem likely.
48
Wear and Tyne Hydropower Survey
Key Numbers:
Site Name
26 - Eastgate Bridge
Head (m)
Installed
power (kW)
1.3
40
Annual gross
Initial cost Annual cost
revenue
£223,289
49
£2,622
£29,342
Simple
payback
(years)
8.4
20 year
simple profit
£311,117
Wear and Tyne Hydropower Survey
3.13
Site 28: Craigside Caravan Park
Observations:
The site lies on the Rookhope Burn to the north of Eastgate. The penstock
would be routed through Craigside Caravan Park to the turbine house which
would be located close to the Warden’s office. The penstock immediately below
the abstraction point may be required to be surface mounted on the exposed
rockface.
Location:
3-Phase O/H
powerline
Figure 42: Map showing location of the potential scheme on the Rookhope Burn. ©
Crown copyright 2010. License number 100049709.
Abstraction Point:
The abstraction point was as identified by Hydrobot. The far bank and the floor
of the river are solid rock. The level of the weir would have to be set carefully to
minimise the back-up and risk of overspill onto the near bank.
50
Wear and Tyne Hydropower Survey
Figure 43: Abstraction point, water flowing from left to right.
Route of Penstock:
The initial routing of the penstock is difficult and will need to circumvent some
exposed rock forming a cliff face of some 50m. Thereafter it can be laid under
the footpath all the way down to the caravan site, then either through the
caravan site or around it.
Figure 44: Samples of the footpath under which the penstock would be run.
Turbine & Generator:
The turbine house would ideally be placed alongside the footbridge shown on
the map and just below the caravan park office. Access would be along the
route of the existing narrow footpath – some widening would be required.
However, this would result in the Eastgate Flow Gauging Station being in the
depleted zone. If this was unacceptable to EA then it would be possible to place
the turbine house above the FGS with a loss of some 6m of head.
51
Wear and Tyne Hydropower Survey
Electrical Distribution Network Interconnection:
The route of the local 3-phase supply is shown on the map. The powerlines
terminate at the church closest to the footbridge – some 150m from the turbine
house.
Figure 45: Transformer adjacent to the church.
Engineering Access:
Access to the abstraction point would be through fields. The penstock would
have to be laid using a mini-digger operating along the footpath, which will
require to be widened.
Environmental Observations:
The Eastgate Flow Gauging Station lies between the desired sites for the
abstraction point and the turbine house. This could be a significant impediment;
an opinion has been requested of the Environment Agency.
The falls present an impassable barrier to migratory fish, as does the weir
associated with the Flow Gauging Station.
52
Wear and Tyne Hydropower Survey
Figure 46: Eastgate Flow Gauging Station.
Key Numbers:
Site Name
Head (m)
28 - Craigside Caravan Park 29
Installed
power (kW)
195
Annual gross
Initial cost Annual cost
revenue
£918,624
53
£10,372
£101,894
Simple
payback
(years)
10.0
20 year
simple profit
£911,808
Wear and Tyne Hydropower Survey
3.14
Site 29: Stanhope Burn Caravan Park
Observations:
The site lies on a tributary of the River Wear to the north of Stanhope, and
adjacent to Stanhope Burn Caravan Park. After a difficult initial penstock section
the route would be through a deciduous wooded area on the bank opposite to
the caravan park.
Scheme Location:
Figure 47: Map showing the location of the scheme. © Crown
copyright 2010. License number 100049709.
Abstraction Point:
The abstraction is at the location identified by Hydrobot, where both banks and
the floor of the river are solid rock, which is advantageous for weir construction.
However, the construction of the weir would cause the river to back-up and
overflow the existing ford – unless the height could be restricted. The alternative
would be to move the weir 50m upstream.
54
Wear and Tyne Hydropower Survey
Figure 48: Location of weir – looking downstream.
Route of Penstock:
The penstock would have to be mounted on the cliff face for the first 50m or so
then again on a second section downstream to keep it above the flood zone.
The remained could be buried in the deciduous wood. A second option would be
to place the scheme on the east bank and run it through the caravan park.
Figure 49: Penstock may have to be mounted on cliff face.
55
Wear and Tyne Hydropower Survey
Figure 50: Route through wood.
Turbine & Generator:
The turbine house would be placed in a field at ‘Cats Pool’, 4m above the level of
the river and 30m from a 3-phase O/H powerline. Access would be through the
field.
An alternative would to be to place it 50m upstream just inside the end of the
deciduous wood to obscure it from sight from the caravan park..
Conclusion: Site valid.
Key Numbers:
Site Name
29 - Stanhope Burn CP
Head (m)
Installed
power (kW)
23
84
Annual gross
Initial cost Annual cost
revenue
£665,030
56
£7,523
£64,445
Simple
payback
(years)
11.7
20 year
simple profit
£473,418
Wear and Tyne Hydropower Survey
3.15
Site 30: Swinhope Burn
Observations:
The site is on the Swinhope Burn south of Westgate.
Scheme Location:
Figure 51: Map showing the location of the scheme. ©
Crown copyright 2010. License number 100049709.
57
Wear and Tyne Hydropower Survey
Abstraction Point:
The weir would be located as identified by Hydrobot® just below the confluence
of the three tributaries, and the water would be routed down the east bank.
However, there may be a requirement to move the abstraction point upstream to
enable the route of the penstock to take a path above the top of the gorge at the
southern most point of the forest shown on the map.
Figure 52: Location of the weir.
Route of Low Pressure Pipe and Penstock:
The penstock route will be required to traverse the scree shown on the right of
the photo below with some significant erosion protection being put in place. It
would then be routed with the intention of remaining above the trees (and top of
the gorge) in the distance (southern most corner of the forest shown on the
map).
58
Wear and Tyne Hydropower Survey
Figure 53: Burn from the abstraction point looking downstream.
The penstock would then be routed in a straight line down the side of the forest
to the point where the farm track enters the forest close to the Hydrobot®
identified site of the turbine.
Figure 54: Sample of the route of the penstock.
Turbine & Generator:
There are three options for the location of the turbine house; the final choice
would be dependent on the firmness of the ground and engineering access.
59
Wear and Tyne Hydropower Survey
These locations are all within 50m of each other and are on the north side of the
farm track shown entering the forest. The current preferred option would be to
place it adjacent to the track for ease of access and avoidance of apparent soft
ground, however this sacrifices some 10m of head.
Figure 55: Preferred turbine house location.
Figure 56: Route of incoming penstock
to site of turbine house – note the O/H
powerline.
Electrical Distribution Network Interconnection:
There is a single phase O/H powerline some 30m up the hill from the turbine
house.
60
Wear and Tyne Hydropower Survey
Engineering Access:
Physical access to all locations is fairly good – mainly though farm access tracks
– except in the area below the turbine house where the tailrace would have to be
placed.
Environmental Observations:
A fish-pass was constructed many years ago to enable migratory fish to avoid
the waterfalls and move to spawning beds upstream. It was reported that the
breeding of fish is still being managed or possibly just monitored. This may be a
significant obstacle that may have to be negotiated through a reduction in the
level of abstraction during times of migration.
Figure 57: Fish-pass just above the site of the discharge point from the turbine house.
Conclusion: Site valid.
Key Numbers:
Site Name
30 - Swinhope Burn
Head (m)
Installed
power (kW)
59
100
Annual gross
Initial cost Annual cost
revenue
£495,508
61
£5,669
£81,957
Simple
payback
(years)
6.5
20 year
simple profit
£1,030,250
Wear and Tyne Hydropower Survey
3.16
Summary of Site Evaluations
A summary of the findings at each of the sites visited is given below in Table 5.
Table 5. Results for each of the 14 sites visited.
Site
Number
TurbNum
Initial
Pdes
(kW)
Site
Evaluation
Pdes (kW)
2
23100355
83
100
4
23001706
200
Nil
7
23000342
91
86 or 100
11A
23002486
67
33
Identified
during site
visit
48
11B
Outcomes
Viable scheme. Potential to develop very much
dependent upon the view of Environment Agency.
Reserve flow set @Q80. Power output was 103kW;
trimmed back to maximise FITs
No scheme – head significantly less than forecast
resulting in penstock being required to traverse highly
fractured rock-face
Viable scheme on FC land. If extended downstream
power could reach 116kW. Trimmed back to
maximise FITs
Forecast abstraction point in a gorge. Alternative AP
found downstream, resulting in reduced head.
Viable scheme subject to the cost of any repairs
required to the weir. Straightforward Archimedes
screw solution
No scheme. Abstraction Point in a gorge, and ‘A’ road
crossing required
13
23001999
86
Nil
20
24100137
534
221
Viable scheme – engineering works confined to end of
large weir.
21
24100081
266
Nil
No scheme - head is only 0.4m
22
24100186
342
Nil
No scheme – weir is only 0.3m and is directly under
the old bridge
25
24100177
127
Nil
26
24100128
118
40
28
24000974
221
195
29
24000659
169
84
30
24000215
129
100
No scheme – EA identified weir is on tributary
Unlikely to be viable due to cost of repair of the weir
likely to be a condition of abstraction licence
Requires civils inspection to determine viability & cost
of 50m or so of rock-face surface mounting of
penstock. £50K added to anticipated costs for civils
Requires civils inspection to determine viability & cost
of 50m or so of rock-face surface mounting of
penstock. £50K added to anticipated costs for civils.
Possibility of using east bank to be examined in more
detail
Viable scheme. Power output was 113kW; trimmed
back to maximise FITs
For each viable scheme the financial analysis, as presented in the site results
above, is also given in Table 6 below.
62
Wear and Tyne Hydropower Survey
Table 6. Financial analysis for each of the sites that were deemed to have a viable scheme.
Installed
Annual
Simple
Head
power
Initial
Annual
gross
payback
Site Name
(m)
(kW)
cost
cost
revenue
(years)
2 - Featherstone Castle
7 - Plashetts Burn
7 - Plashetts Burn - extended
11A - Blaeberry Burn
11B - Blueback Weir
20 - Durham
26 - Eastgate Bridge
28 - Craigside Caravan Park
29 - Stanhope Burn CP
30 - Swinhope Burn
1.3
57
77
35
3.5
2.5
1.3
29
23
59
99
86
100
33
48
221
40
195
84
100
£398,054
£430,151
£373,919
£309,135
£234,195
£876,299
£223,289
£918,624
£665,030
£495,508
63
£4,597
£4,941
£4,332
£3,558
£2,752
£9,917
£2,622
£10,372
£7,523
£5,669
£75,365
£72,973
£90,767
£26,952
£38,369
£131,161
£29,342
£101,894
£64,445
£81,957
5.6
6.3
4.3
13.2
6.6
7.2
8.4
10.0
11.7
6.5
20 year
simple
profit
£1,017,308
£930,485
£1,354,784
£158,744
£478,140
£1,548,585
£311,117
£911,808
£473,418
£1,030,250
Wear and Tyne Hydropower Survey
4
Analysis and Discussion
4.1
General Features
The nature of the landscape and the extent of urbanisation within the study area
has a significant effect on the hydro potential within the Wear and Tyne
catchments. In comparison to an area such as the Scottish Highlands, there are
many more areas with rolling, gentle hills or no hills at all. This has two effects:
firstly there is less elevation available for developing the head required in a good
run-of-river hydro scheme. Secondly the area is suitable for habitation and
transport infrastructure. The combined effect is that hillside-based hydro sites
are less productive than a typical developer might wish, and more prone to
obstacles. Many sites that might be viable in a different region are either too
costly to mitigate, or too difficult from a construction point of view. Even so there
are many technically viable high-head sites, and the resource is surprisingly
under-exploited.
The advantage that the Wear and Tyne catchments have is a good history of
industries that relied on water power to drive mills and other machinery. As a
result there are many disused weirs across the region and many are serviceable
or have been upgraded. Such industrial sites are often regarded as less
environmentally sensitive as they have already been modified. They may already
include a fish ladder, and frequently the area has continued to be populated with
a good connection to the electricity distribution grid. With the recent introduction
of Feed-In Tariffs, low-head sites can be financially attractive and
environmentally benign.
While the Wear and Tyne catchments have not been a Mecca for hydro
developers looking for a fast return, for smaller developers and particularly
landowners the region is littered with favourable investment opportunities.
4.2
Quality of Inputs and Results
4.2.1
Elevation data and the Detailed River Network
Ordnance Survey’s Landform Profile elevation data is accurate to ±2.5m, with
greater inaccuracy in mountainous areas. For run-of-river sites in Wear and Tyne
this proved to be adequate, with the greatest possible error being 5m in schemes
with a head typically greater than 50m. False positive results were generally
caused by disagreements between the Environment Agency’s Detailed River
Network, and the course that water would naturally run were it simply draining
from the surface portrayed by the Landform Profile data. In such cases
Hydrobot® might simulate a penstock running up a high bank, generating the
impression of a steep river section where none exists. Most cases were
identified automatically by the combination of short penstock, high head and high
flow.
Man-made features crossing rivers, such as wide rail or road bridges, or dense
trees, also created some false positives, but their detection has to be more
manual. The number of these false positives is greater in areas of higher
population density, as described above.
64
Wear and Tyne Hydropower Survey
4.2.2
The Environment Agency’s Barriers dataset
The Barriers dataset compiled for use in ‘Opportunity and Environmental
Sensitivity Mapping for Hydropower in England and Wales’ contains a vast
amount of valuable information, but it also contains a number of spurious entries
that do not correspond to any detectable barrier in the watercourse. Visits to
such non-existent barriers could have been avoided were it not for the
methodology used to estimate their heights.
A combination of satellite and traditional elevation data was used in the EA’s
hydro mapping to effectively establish the elevation upstream and downstream
of each barrier, with the difference representing the head available for hydro
generation. In essence this is the same method used by Hydrobot® in Scotland.
However, the consultant in the Sensitivity Mapping ran into the same issues
described in section 4.2.1 above, namely that data accuracy, river crossings and
differences with the Detailed River Network often leads to incorrect estimates of
height. These will naturally include some negative heights where it appears that
the height downstream is greater than that upstream. As several slightly different
sources and sampling methods were being used, there was usually a choice for
each barrier. In the Sensitivity Mapping, obtaining a height for each barrier may
have been the main priority, as the methodology effectively skews the mean
estimate for each barrier towards the high end. The result is false barriers, with
some heights predicted being many times greater than the actual height.
To alleviate this problem, Hydrobot® used a combination of the Detailed River
Network and the surface flow model. Barriers were plotted on the Detailed River
Network, but then located onto the nearest point on the river course determined
by the surface flow model. Upstream and downstream elevations were sampled
from the surface flow model, thus avoiding high banks which were responsible
for the most erroneous results. The estimates of height are still theoretically
subject to a to ±2.5m error from the Landform Profile data, though as the
significant weirs are generally on larger, flatter rivers, the Landform Profile data
are normally more accurate than this.
The revised methodology was still subject to errors due to river crossings and
trees, and these were identified manually during technical screening.
4.2.3
Technical screening
Unsurprisingly, Hydrobot® identified less hydro potential per unit area than in
Scotland, but still came up with 167 sites within the Wear and Tyne catchments
that would show a profit in less than 20 years, including inflation and interest on
a loan. Of these, 86 remained after technical screening. It is worth asking
whether the rejected schemes could not have been excluded at an earlier stage.
The majority of the schemes that failed technical screening were in gorges. This
is where the river or stream has, over millennia, eroded a deep channel into the
soil or, in some cases, bedrock. Experience shows that many gorges have one
or more short flat sections along one or both banks that can allow a penstock to
safely diverge from the river course. Detecting such a pipe corridor automatically
is near impossible – a human eye and knowledge of what engineering can
achieve is imperative. To avoid losing sites that in fact could be viable, the
threshold for excluding a gorge site has been relaxed. This necessarily includes
a number of false positives in the results, but cuts the number of false negatives.
65
Wear and Tyne Hydropower Survey
While human intervention was required to skim through and remove a quarter of
identified sites due to gorges, it is relatively quick and efficient.
There were 21 false positives caused by false barriers and elevation data
inaccuracy, as discussed in section 4.2.1, and 13 by other obstacles. Both of
these sources of error are unavoidable without another full exercise to map the
elevation of the Wear and Tyne catchments in greater detail than existing
satellite data. Naturally this defeats the purpose of using a desk-based model, as
the cost would be completely disproportionate to the benefits.
Therefore the rate of identified schemes passing technical screening is a result
of the precautionary approach preferred by the modellers, rather than
underperformance by the model.
4.2.4
Site Evaluations
The correlation between the location of the site of the schemes identified by
Hydrobot® and the preferred option developed as a result of the site visit was
very good, with a few well understood exceptions. Of the seven medium-head
schemes examined one turned out not to be viable and for the remaining six
there was a positive match for the turbine locations and for four there was a
good match for the abstraction point. Of the six low-head schemes three
schemes were a good match with the other individuals being;
a. too low to be effective as a weir
b. wrongly identified as being on the Wear whereas in fact it was on a minor
tributary
c. misplaced upstream by 200m from the actual weir
In terms of scale of hydropower the correlation between Hydrobot® modelling
and the site visit findings for viable sites was good with a few exceptions. The
reasons for the discrepancies have been identified.
66
Wear and Tyne Hydropower Survey
5
Conclusions and Recommendations
babyHydro’s automated survey of over 1,500 sites within the Wear and Tyne
catchments to identify opportunities for new hydro developments has led to the
discovery of more than 80 technically and financially viable sites. The Site
Evaluation exercise demonstrated that, of these 80, around one third may get
ruled out at an early stage due to physical features or other obstacles that could
not be predicted by Hydrobot, the GIS model used for the desk-based element of
the study.
Of the remaining 75 sites that have not yet had a Site Evaluation, some
landowners may already have thought about the hydro potential of their asset,
but some would have remained undiscovered had this study not been
commissioned. In both cases, practical action is required to ensure the
opportunities are not wasted.
Firstly, research time is required to establish land ownership for the sites so that
the interest of the owner can be gauged. This has proven to be a lengthy task,
as making contact with an owner can be far more onerous than just obtaining
their details.
Where favourable, they could then be assisted in progressing their scheme
through the development process, or finding a suitable developer/investor if they
are not interested in financing the scheme themselves. There is limited
assistance available for hydro entrepreneurs despite the lack of hydro
professionals willing to deal with schemes smaller than 500kW. Therefore some
form of local, publicly-funded assistance could pay for itself in terms of local
wealth creation and regional renewable energy targets.
As well as sites identified in this study, there is likely to be a number of
commercially viable hydro sites that did not show up. This could be perhaps
because the existing infrastructure was not included in the datasets used, or
because of some unusual topography that defies the norm but favours hydro.
The result is that there will be site owners or interested parties in the Wear and
Tyne catchments who know they have hydro potential, but may not know where
to turn. There will also be owners of sites identified in this survey, who could not
be contacted directly. This audience could be captured by means of a suitable
event, publicising the results of the survey and offering assistance where
needed.
There has also been discussion of an interactive tool to allow people to search
the results by a map interface. By stimulating interest and discussion about local
development, the critical mass for an active hydro community can be reached. It
is through such groups that individuals gain the courage to begin a hydro
development they may have pondered for years. And it is with the support of
such groups that individuals persevere in the face of opposition or bureaucracy
to complete a hydro development. Therefore, to truly realise the benefits of the
hydro potential in the Wear and Tyne catchments, it is necessary to broadcast
the results of this study, and to provide a forum in which the audience can turn
theory into practice.
67
Wear and Tyne Hydropower Survey
Appendix 1: Longlist of Sites Identified by Hydrobot®
The following table lists sites found to be financially viable, and also technically
viable following screening using OS maps.
TurbNum
23000072
23000153
23000166
23000249
23000289
23000342
23000451
23000722
23000732
23000743
23000782
23000816
23000863
23000875
23000919
23001009
23001012
23001047
23001063
23001066
23001087
23001150
23001194
23001236
23001308
23001362
23001454
23001536
23001596
23001629
23001706
23001780
23001782
23001999
23002030
23002115
23002119
23002192
23002243
23002247
23002268
23002333
23002480
23002486
23002492
23002495
GridRef
NY763867
NY900878
NY933914
NZ761035
NY878865
NY659918
NY605948
NY936936
NY825973
NT809004
NT782000
NY726877
NT737024
NY623935
NY609866
NY804911
NY715882
NY625949
NY875863
NY737686
NY807856
NY687853
NY863688
NY925863
NY630844
NY669641
NY771658
NY813850
NY874862
NY994657
NY746812
NY747631
NY789608
NY673564
NY829634
NY753625
NY780573
NY791586
NY883540
NY682563
NY948587
NY725626
NY786606
NY769561
NY710588
NY995590
Pdes Qdes Head
(kW) (m3/s) (m)
23 0.035
88
61 0.133
59
27 0.062
57
29 0.022 168
12 0.012 137
91 0.208
57
62 0.143
57
35 0.264
17
73 0.237
40
40 0.088
59
87 0.392
29
22 0.072
40
10 0.014
93
27 0.037
94
10 0.019
68
31 0.242
16
59 0.111
69
11 0.016
87
18 0.018 128
77 0.505
19
11 0.019
78
73 0.201
47
31 0.073
56
48 0.138
45
10 0.019
64
11 0.014
96
49 0.132
48
17 0.028
78
10 0.011 117
45 0.132
45
200 0.910
28
33 0.055
79
37 0.049
99
86 0.128
88
10 0.023
55
29 0.044
86
31 0.052
78
73 0.169
57
59 0.112
68
23 0.018 168
25 0.068
48
24 0.046
68
13 0.022
80
67 0.129
68
55 0.156
46
39 0.096
53
Capital
cost (£)
152,891
310,615
210,564
200,749
103,465
479,767
370,753
242,367
477,300
310,346
528,459
171,941
77,158
176,812
79,566
197,012
304,876
88,731
119,021
445,493
93,842
396,946
189,484
347,975
74,049
90,145
328,815
125,370
72,726
328,827
869,317
182,286
194,564
375,459
82,335
217,501
209,899
359,633
329,463
118,425
187,561
172,383
110,263
345,011
343,695
256,094
68
Annual
Net
Simple
Energy Operating revenue payback
Turbine
(kWh) cost (£/yr) (£/Yr)
(years)
Type
100,957
2,054 18,945
8.1 Pelton
256,383
4,205 49,123
6.3 Pelton
117,366
2,736 21,676
9.7 Pelton
124,674
2,646 23,286
8.6 Pelton
52,252
1,376 10,590
9.8 Pelton
389,452
6,390 74,616
6 Pelton
264,769
4,885 50,187
7.4 Pelton
142,551
3,175 26,476
9.2 Francis
309,277
6,173 58,156
8.2 Pelton
171,775
3,978 31,751
9.8 Pelton
368,489
6,887 69,759
7.6 Pelton
98,467
2,252 18,229
9.4 Pelton
43,100
1,057
8,813
8.8 Pelton
116,021
2,360 21,773
8.1 Pelton
43,564
1,084
8,892
8.9 Pelton
125,370
2,628 23,449
8.4 Francis
257,260
4,120 49,390
6.2 Pelton
47,275
1,197
9,629
9.2 Pelton
77,278
1,620 14,454
8.2 Pelton
307,959
5,860 58,195
7.7 Francis
48,491
1,258
9,846
9.5 Pelton
317,997
5,287 60,857
6.5 Pelton
134,268
2,548 25,380
7.5 Pelton
202,956
4,475 37,740
9.2 Pelton
41,991
1,018
8,598
8.6 Pelton
45,587
1,208
9,232
9.8 Pelton
210,297
4,282 39,459
8.3 Pelton
71,558
1,673 13,211
9.5 Pelton
42,689
1,009
8,767
8.3 Pelton
191,941
4,239 35,685
9.2 Pelton
782,928
11,810 97,800
9 Francis
141,552
2,492 26,950
6.8 Pelton
155,951
2,669 29,769
6.5 Pelton
359,031
5,194 69,485
5 Pelton
42,198
1,113
8,551
9.6 Pelton
123,747
2,833 22,907
9.5 Pelton
129,536
2,769 24,175
8.7 Pelton
304,051
4,882 58,360
6.2 Pelton
236,504
4,395 44,797
7.4 Pelton
98,986
1,677 18,912
6.3 Pelton
103,837
2,458 19,140
9.8 Pelton
102,354
2,277 19,013
9.1 Pelton
56,298
1,464 11,429
9.6 Pelton
279,527
4,657 53,484
6 Pelton
228,520
4,505 43,028
8.0 Pelton
160,471
3,368 30,009
8.5 Pelton
Wear and Tyne Hydropower Survey
TurbNum
23002553
23002582
23002593
23002776
23002868
23002969
23003085
23003571
23003982
23100065
23100097
23100230
23100244
23100334
23100355
23100492
23100542
23100609
23100658
24000043
24000174
24000215
24000494
24000515
24000659
24000853
24000929
24000947
24000974
24000976
24100007
24100011
24100066
24100081
24100127
24100128
24100136
24100137
24100177
24100186
24100190
24100209
24100221
GridRef
NY757555
NY717578
NY812568
NY847499
NY713490
NY949469
NY851461
NY766519
NY659517
NY683619
NY781566
NY898877
NY868831
NY664663
NY672611
NY903749
NY807770
NY804597
NY683620
NZ004347
NY893374
NY909375
NY925382
NY946401
NY990396
NZ243518
NY844414
NZ059415
NY952390
NY985410
NZ191303
NY879383
NY948398
NZ272417
NZ006378
NY956384
NZ163311
NZ271421
NZ001383
NZ265377
NZ271375
NZ159310
NY866390
Pdes
(kW)
47
50
9
46
77
23
26
45
24
30
32
34
38
34
83
23
28
180
33
43
32
129
45
31
169
62
28
24
221
32
57
43
34
266
51
118
158
534
127
342
24
56
62
Annual
Qdes Head Capital
Energy Operating
(m3/s) (m)
cost (£)
(kWh)
cost (£/yr)
0.057 109 255,769 198,233
3,458
0.114
57 305,631 210,567
4,039
0.010 118
77,282
39,217
1,050
0.062
97 193,437 184,333
2,758
0.208
48 423,621 322,528
5,629
0.030 101 147,431
91,784
1,994
0.061
57 164,559 104,334
2,218
0.061
96 246,557 187,780
3,330
0.033
95 140,623 103,483
1,932
0.819
5 188,445 123,792
2,527
1.638
3 196,349 125,935
2,628
6.295
1 234,788 138,463
3,078
6.574
1 248,413 154,458
3,274
0.884
5 190,201 140,420
2,589
10.799
1 407,878 333,806
5,521
0.588
5 156,366
93,282
2,085
0.876
4 176,549 114,080
2,366
4.669
5 563,587 730,666
8,241
10.721
0 232,408 134,907
3,042
0.050 110 221,674 171,770
3,031
0.035 117 161,622 125,725
2,249
0.270
62 532,164 501,403
7,367
0.055 108 200,728 179,774
2,830
0.049
81 182,695 123,133
2,470
0.522
41 566,709 607,581
8,166
0.191
42 409,817 239,968
5,314
0.054
67 168,114 107,275
2,274
0.036
85 157,471
94,438
2,111
0.961
29 832,271 786,907
11,625
0.083
50 200,229 126,654
2,674
6.697
1 321,962 222,450
4,290
2.006
3 268,507 159,130
3,554
0.869
5 202,082 127,149
2,713
13.264
3 1,171,304 1,002,256
15,809
5.092
1 303,393 191,691
4,023
4.240
4 473,933 461,379
6,607
7.601
3 646,966 636,330
8,933
14.737
5 1,538,450 1,903,779
22,568
5.170
3 515,353 494,200
7,166
11.377
4 962,324 1,279,877
14,287
0.615
5 165,057
91,869
2,193
7.181
1 341,289 217,984
4,487
1.614
5 301,223 225,165
4,121
69
Net
Simple
revenue payback
(£/Yr)
(years) Turbine Type
37,774
6.8 Pelton
39,759
7.7 Pelton
7,930
9.7 Pelton
35,584
5.4 Pelton
61,457
6.9 Pelton
17,097
8.6 Pelton
19,483
8.4 Pelton
35,728
6.9 Pelton
19,592
7.2 Pelton
23,222
8.1 Archimedes
23,566
8.3 Archimedes
25,722
9.1 Archimedes
28,853
8.6 Archimedes
26,618
7.1 Archimedes
63,911
6 Archimedes
17,317
9.0 Archimedes
21,363
8.3 Archimedes
94,052
6.0 Kaplan
25,019
9.3 Archimedes
32,697
6.8 Pelton
23,902
6.8 Pelton
62,829
8 Pelton
34,563
5.8 Pelton
23,142
7.9 Pelton
76,895
7 Francis
44,600
9.2 Pelton
20,039
8.4 Pelton
17,532
9.0 Pelton
98,542
8 Francis
23,670
8.5 Pelton
41,979
7.7 Archimedes
29,545
9.1 Archimedes
23,734
8.5 Archimedes
124,507
9.4 Kaplan
35,849
8.5 Archimedes
57,986
8 Kaplan
80,153
8.1 Kaplan
243,961
6 Kaplan
62,022
8 Kaplan
164,896
6 Kaplan
16,915
9.8 Archimedes
40,853
8.4 Archimedes
42,713
7.1 Archimedes
Wear and Tyne Hydropower Survey
70
CPI
Wilton Centre, Wilton,
Redcar TS10 4RF
T: 01642 455 340
e-mail: [email protected]
Gateside Farm
Kilncadzow
Carluke ML8 4QN
T: 01786 820 018
e-mail: [email protected]