Sustainable utility supply
in Aalborg
1
Sustainable utility supply in Aalborg
Number printed: 2000
Paper: Profi silk 115 gr.
Cover: Profi silk 200 gr.
Swanlabel paper
Publisher: City of Aalborg, The Public Utility Companies
February 2004
Table of contents
1. Sustainable utility supply in Aalborg - Summary .................................................... 6
2. Society in growth .................................................................................................... 8
3. National goals and instruments for energy ........................................................... 12
4. Energy in the Municipality of Aalborg ................................................................... 15
5. The Public Utility Companies’ supply of energy in Aalborg .................................. 18
6. The District Heating Utility Company .................................................................... 20
7. The Electric Utility Company – AKE Net ............................................................... 32
8.
The Gas Utility Company ..................................................................................... 38
9. National goals and instruments for water and waste water .................................... 44
10. Water and waste water in the Municipality of Aalborg ........................................... 46
11. The Water Utility Company .................................................................................. 50
12. The Sewage Utility Company ................................................................................ 54
13. National goals and instruments for waste ............................................................. 58
14. Waste in the Municipality of Aalborg .................................................................... 60
15. The Refuse Collection Utility Company ................................................................ 62
3
Steam train safeguards drinking water. The railway from
the centre of Aalborg to the East Harbour runs close by
vulnerable groundwater sources, from which drinking water
to most of Aalborg is recovered. In order to prevent the risk of
pesticides and herbicides seeping into the groundwater, the
track is kept free of weeds exclusively by means of steam.
The steam is blown down onto the railway track from an old
train to which special equipment has been fitted. Six runs
with steam during the course of the summer are sufficient to
keep the weeds under control.
Photo: Baghuset/Ajs Smed Nielsen
4
Sustainable utility supply - global and local
Public utility supply is about how households and businesses receive energy and
water, and how waste water and solid
waste are disposed of and treated.
Utility supply plays a decisive role in
terms of the environment. The world’s
population continues to grow, and the
resulting increase in human needs and
activities, including the supply of utility
services, in many respects poses a threat
to the environment, both locally and
globally. A discharge of untreated effluent
can have disastrous consequences for the
ecosystem in an individual watercourse,
whereas the continued increase in the
emission of greenhouse gases can have
serious consequences for the climate on
a global scale.
Through the UN and the EU, Denmark
has signed a number of international
conventions and protocols aimed at safeguarding a sustainable development of
the global environment. A sustainable development is a development that satisfies
current demands without jeopardising
the ability of future generations to satisfy
their own needs. These conventions and
protocols cover the following areas of
utility supply:
energy
water/waste water
waste
The Public Utility Companies’ alderman,
Mariann Nørgaard.
The Danish government has drawn up
a number of plans that supplement the
international conventions with specific
national goals. These include climate
strategy, plans for the aquatic environment and waste strategy.
Locally, the City Council in Aalborg
has drawn up a number of plans, the purpose of which is to ensure that the goals
in the international and national agreements are met – and preferably exceeded.
The fundamental step was taken with the
Brundtland Plan in 1992. As a follow-up
to the Brundtland Plan, a specification
of the total energy consumption in the
municipality was drawn up in 2002 in the
form of an energy balance for the total
energy consumption excluding transport.
The principles for sustainability are
continuously being integrated into the
plans concerning heat supply, water
supply, waste water and solid waste for
the entire municipality, as well as into the
strategic plans for each of the municipal
Public Utility Companies.
It is the responsibility of the Public
Utility Companies, as the administrative
body on behalf of the local authority in
Aalborg, to ensure that these plans are
realised. The Public Utility Companies
also have operating responsibility for the
vast majority of public utility supply in
Aalborg with respect to energy, water/
waste water and solid waste.
Ensuring a sustainable utility supply
in Aalborg is a crucial task for the Public
Utility Companies. Between them they
supply 86% of the total net energy
consumption to customers in the Municipality of Aalborg, excluding Aalborg
Portland and excluding transport. We
therefore consider it a logical development to follow up on the Brundtland Plan
and take stock of what we have achieved
– and what we can hope to achieve in the
years ahead.
5
1. Sustainable utility supply in Aalborg - Summary
Aalborg is making good progress towards
a sustainable utility supply, having
achieved major results in terms of the
international and national goals that have
been set up in this area.
In terms of energy, there is every indication that the Municipality of Aalborg
can achieve the national goal of reducing
the total CO2 emission by 21% in 2012
in relation to the 1990 level. Assuming
1.1
that the transport sector’s CO2 emission
continues to grow as it has hitherto, the
utility supply sector’s CO2 emission will
have to be reduced by approx. 33%.
In 1990 the CO2 emission in the
municipality was 0.9 million tonnes,
excluding Aalborg Portland and excluding transport. In order to achieve the
target of 33%, emission in 2012 must be
reduced to 0.6 million tonnes. The Public
Emission of CO2 in the Municipality of Aalborg
1.0
0.9
Mill. tonnes CO2
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
1990
2002
2012
Emission of CO2 in the Municipality of Aalborg, excl. transport and excl. Aalborg Portland, in 1990 and 2002, and the target for 2012.
(Source: Energy Balance for the Municipality of Aalborg).
6
Utility Companies expect that this can be
achieved by means of a number of initiatives, including:
increased utilisation of surplus heat
from Aalborg Portland and Reno-Nord
for district heating
greater efficiency of the Public Utility
Companies’ plants and operations
more comprehensive consultancy
services offered to householders and
businesses
increased use of renewable energy in
the electricity supply
savings in industrial processing
energy consumption
continued conversion from oil burners
to district heating, natural gas, straw
and wood.
An important precondition is that the
surplus heat used for district heating is
considered to be CO2-neutral, which is in
accordance with accepted principles. The
emission of CO2 from Aalborg Portland
and Reno-Nord is therefore not included
in the District Heating Utility Company’s
CO2 calculations.
In terms of water resources, the local
authority in Aalborg is an international
leader with regard to the active protection of groundwater. In cooperation with
the private waterworks, Aalborg is – as
For the sake of our children. A sustainable development is a development that satisfies current demands without jeopardising the ability of
future generations to satisfy their own needs.
Photo: Aalborg Tourist & Convention Bureau
one of only a handful of municipalities in
Denmark – in the process of safeguarding the future supply of drinking water by
protecting the groundwater in particular
catchment areas. This is taking place by
means of afforestation and restrictions
on land use in these protected areas.
Drastrup is the first protection area. The
first tests carried out here - of nitrate
content in the water at a depth of one metre – have demonstrated that protection
is effective. Next year a large area near
Visse is expected to be designated for
groundwater protection, and more areas
will follow in due course. As a result,
Aalborg is expected to continue to have a
supply of clean drinking water in the form
of untreated groundwater.
In terms of waste water, the centralisation of sewage treatment at two major
treatment plants in Aalborg has proved to
be of enormous benefit since these large
sewage treatment plants are much more
efficient than small sewage treatment
plants. The four remaining small plants in
the municipality are due to be taken out of
service during the course of the next three
years. The discharge of organic material
and nutrient salts into the Limfjord and
watercourses has been reduced dramatically as a result of improved sewage
treatment and the ongoing renovation of
the sewer network.
The Municipality of Aalborg is fully
in line with the national goals set out in
the Danish government’s Waste Strategy
Plan. In brief, the Waste Strategy Plan
aims at increasing the proportion of
waste used in recycling and reducing the
proportion that is deposited at landfill
sites, in addition to utilising the remaining waste – combustible waste – in the
production of heat and power.
In 2002, 72% of Aalborg’s waste was
recycled, 19% was incinerated and 9%
was deposited at landfill sites. The corresponding national targets for 2004 are
64, 24 and 12% respectively.
7
2. Society in growth
Both globally and locally, the goals of
limiting CO2 emission, safeguarding
clean drinking water and reducing the
production of waste should be seen in the
context of the continued global growth in
population and production.
During the period from 1990 to 2002
the population in Denmark increased
from 5.14 to 5.37 million, a growth of
some 4.3%. If this level of growth continues, the population in 2010 is expected to
stand at 5.43 million.
The growth in population has been
largest in relative terms in the major cities
in Denmark. In the Municipality of Aalborg, the number of inhabitants increased
from 155,019 to 162,264 in the period
from 1990 to 2002, a growth of 4.5%.
Production has also increased.
Denmark’s GDP was DKK 916 billion
(1995 price levels) in 1990. In 2002 the
country’s GDP had risen to DKK 1,194
billion (1995 price levels), corresponding
to an increase of 30.4%.
2.3 Jobs broken down into disciplines
14%
1%
Public services
Retail trade and hotels
6%
40%
14%
Building and construction
Banks and insurance
Agriculture and fishing
6%
19%
2.1
Number of jobs - Municipality of Aalborg
14%
1%
Public services
96,000
Retail trade and hotels
6%
94,000
40%
92,000
14%
Building and construction
88,000
Banks and insurance
86,000
Agriculture and fishing
6%
84,000
19%
82,000
80,000
1990
1992
1994
1996
1998
2000
Number of jobs in the Municipality of Aalborg in the period 1990 to 2002.
(Source: City of Aalborg, Statistics and personnel department)
8
Transport and communication
Manufacturing
90,000
2002
Transport and communicati
Manufacturing
Jobs in the Municipality of Aalborg in
2002 broken down into disciplines.
(Source: City of Aalborg, Statistics and
personnel department)
Gross domestic product in Denmark
2.4
1.200
1,000
800
DKK billion
During the same period the total production of goods in Denmark increased
by 24.7% and private consumption by
22.6%.
In 2002 there were 12,600 business
enterprises in the Municipality of Aalborg
employing a total of 94,600 people.
Despite the increase in gross domestic
product and private consumption,
Denmark’s gross energy consumption
– energy consumption including losses
associated with the production and
distribution of electricity and heat (fuel
consumption) – in 2002 was, following
a slight rise at the end of the 1990s, at
approximately the same level as in 1990.
The composition of the consumption
of energy has changed, however, since
coal has to a large extent been replaced
600
400
200
0
1990
1992
1994
1996
1998
2000
2002
Denmark’s gross domestic product, GDP, in DKK billion (1995 price levels).
(Source: Statistics Denmark)
2.5
Gross energy consumption in Denmark
900,000
Aalborg is a city enjoying growth,
and boasts a rich variety of shops
and businesses.
Photo: Aalborg Tourist & Convention Bureau.
800,000
700,000
TJ
600,000
500,000
400,000
1995
1996
1997
1998
1999
2000
2001
2002
300,000
200,000
100,000
0
915,918 926,13 931,786 931,773 982,704 1009,756 1035,188 1065,929 1092,236 1121,019 1153,476 1169,943 11
1990
1992
1994
1996
1998
Oil
Natural gas
Coal and coke
Renewable energy, etc.
2000
2002
Denmark’s gross energy consumption in TJ broken down into energy types.
(Source: Statistics Denmark)
9
2.7
Water consumption in Denmark
1,200
1,000
800
Mill. m3
by natural gas and renewable forms of
energy.
During the 1990s the Danes purchased
more consumer durables. Many of these
consumer goods have an effect on the
consumption of both energy and water
during their service lives, and they also
affect volumes of waste when they are
replaced.
600
400
200
0
90
91
92
93
94
95
96
97
98
99
00
01
Consumption of water in Denmark in million m3, 1990-2001. (Source: Statistics Denmark)
Ownership of consumer durables
2.6
100
2.8
Quantities of waste in Denmark
80
15
%
60
12
Mill. tonnes
40
20
0
6
1990
2000
2010
Washing machines
Tumble dryers
Dishwashers
Video recorders
Microwave ovens
Mobile phones
Personal computers
Household ownership of consumer durables in %. (Source: Statistics Denmark)
10
9
3
0
1994
1996
1998
2000
Development in quantities of waste in Denmark.
(Source: Waste Statistics 2002, Danish Environmental Protection Agency)
2004
The number of cars on Danish roads is increasing steadily. The same is true of the transport
sector’s emission of CO2 – and the number of
cars that end up on the scrap heap.
Photo: City of Aalborg
11
3. National goals and instruments for energy
12
3.1
Emission of greenhouse gases in Denmark
90
80
Mill. tonnes CO2 equivalents
Limiting the emission of CO2 and other
greenhouse gases is the overriding goal
in the energy area. Greenhouse gases are
the chief cause of global warming. The
emission of CO2 is closely linked to the
use of fossil fuels. To a large extent, the
reduction is thus an indication of how far
we have come with regard to implementing renewable energy forms and energyefficient technology.
Denmark has signed the UN’s Kyoto
Protocol, in which the goal in global
terms is to limit the emission of greenhouse gases by 5% in 2008-2012 in
relation to 1990 levels.
In the EU’s Environmental Action
Programme the target for Europe is
somewhat stricter, with a reduction of
8 % being stipulated. In the case of
Denmark, this target has been revised
upwards to 21% in accordance with the
internal burden sharing agreement drawn
up between the EU member states.
The national goal of limiting CO2
emission by 21% cannot be directly
transferred to the utility supply sector.
Utility supply makes up only a part of
the total energy consumption, which
is distributed between several sectors:
household, transport, trade and industry,
energy production and agriculture.
70
60
50
40
30
20
10
0
1990
CO2
2000
Methane
2010
Unregulated
Laughing gas
Target 2010
Industrial gases
Emission of greenhouse gases in Denmark. (Source: A cost-effective climate strategy)
The transport sector, which accounts
for a significant proportion of the CO2
emitted, is completely separate from
the utility supply area. This sector’s CO2
emission continues to increase, and no
decisive steps have been taken to counter
this development. Indeed, in its paper
outlining its proposal for climate strategy
from 2003, the government expects the
continued increase of emission of CO2
within the transport sector. This of course
results in much greater demands on the
other sectors.
From 1990 to 2002 the transport
sector’s CO2 emission increased from
10.5 to 12.3 million tonnes. If this growth
continues, the figure will climb to 13.2
million tonnes by 2010. Approximately
3.2
The transport sector’s proportion of CO2 emission
90
80
70
Mill. tonnes CO2
90% of the transport sector’s CO2 emission comes from road transport.
The increase in CO2 emission from
transport means that other sectors will
have to reduce their combined CO2 emission from 42.1 to 28.4 million tonnes in
order to achieve the overall goal of 41.6
million tonnes of CO2. This corresponds
to a reduction of approximately 33%.
In terms of CO2 emission per inhabitant, the projected increase in population
places even greater demands on the
reduction of CO2 before 2010. The per
capita CO2 emission in Denmark will thus
have to be reduced by almost 37% during
the period 1990 to 2010.
60
50
40
30
20
10
0
1990
Of which, CO2 from transport
2000
Target 2010
The remaining emission of CO2 in Denmark
The transport sector’s proportion of the total CO2 emission in Denmark.
(Source: A cost-effective climate strategy and Denmark’s greenhouse account)
3.3
CO2 emission per inhabitant in Denmark
9
8
7
6
Tonnes CO2
Switch off your engine, is the
message to car drivers when
the bridge over the Limfjord
is raised. Photo: Ajs Smed
Nielsen
5
4
3
2
1
0
1990
2000
Target 2010
CO2-emission pr. indbygger i Danmark
CO2 emission per inhabitant in Denmark, excl. contribution from transport. (Source: A
cost-effective climate strategy. Denmark’s greenhouse account and Statistics Denmark)
13
A large number of measures have been
implemented both through the EU and
at national level in order to reduce CO2
emission, including:
increased duties on fossil fuels
greater use of renewable energy
development of combined heat and
power
statutory requirements with regard
to advice to electricity, heat and gas
consumers
energy labelling of equipment and
appliances
increased funds for research
These measures have all had an effect,
both nationally and locally.
Taxes and duties on energy have been
regularly increased throughout the 1990s.
During the period from 1998 to 2002
alone, taxes and duties levied on fossil
fuels in Denmark increased by almost
20%.
Within the field of renewable energy
sources, the production of wind energy in
particular has been increased such that
today it provides about 15% of the Danish electricity consumption. In accordance with legislation on electricity supply,
almost half of the electricity consumption
is charged as “prioritised energy” at
centrally fixed prices, which has made it
profitable to produce electricity by means
of wind power and other alternative
energy sources.
When making decisions concerning
the location of windmills, it is important
to take account of wind conditions,
aesthetics and noise. For example,
within the Municipality of Aalborg, the
14
City Council has specified a number of
areas in which windmills may be erected.
Electricity production from windmills in
the Municipality of Aalborg has increased
from approximately 8,600 MWh in 1990
to 116,000 MWh in 2002.
The national natural gas network
has undergone considerable development, and the number of decentralised
combined heat and power plants has
increased correspondingly during recent
decades. The cogeneration of heat and
electricity is more efficient than individual
heating with oil burners and separate production. In major cities the district heating networks have been expanded and the
power stations made more efficient.
Windmill of the future. NEG Micon – now part
of the world’s biggest windmill manufacturer,
Vestas – has erected a completely new type of
windmill in Aalborg that will be the forerunner
of future offshore wind turbines. The windmill is
operated by Elsam and serves as a research mill
for Aalborg University. Photo: NEG Micon
4. Energy in the Municipality of Aalborg
increased connection to the district
heating network
further utilisation of surplus heat from
the Aalborg Portland cement factory
reduction of temperature in the District Heating Utility Company’s supply
network
energy savings in municipal buildings
and in urban renewal
greater natural gas supply in surrounding villages
4.1
Gross energy consumption in the Municipality of Aalborg
30,000
25,000
20,000
TJ
As a supplement to Danish national legislation and the international conventions
and protocols that Denmark has signed
through the UN and the EU, the City of
Aalborg has in recent years drawn up a
number of plans aimed at promoting a
sustainable public utility supply.
In 1992 the City Council in Aalborg
adopted a Brundtland Plan that specifies
a number of concrete, local, potential
areas of action in the utility supply area.
The principles for sustainability have
been continuously integrated into the
plan for heat supply for the Municipality
of Aalborg and strategic plans for the
Public Utility Companies.
Elements contained in the Brundtland
Plan include:
15,000
10,000
5,000
0
1990
2002
Energy consumption, remainder of the Municipality of Aalborg
Energy consumption, Aalborg Portland
Gross energy consumption in the Municipality of Aalborg (Source: Energy Balance for
the Municipality of Aalborg)
As a follow-up to the Brundtland Plan,
the Public Utility Companies have drawn
up a so-called energy balance for both
1990 and 2002 covering the total energy
consumption in the Municipality of
Aalborg excluding transport. The energy
balance reflects one overwhelming aspect
in terms of energy consumption in the
Municipality of Aalborg: The Aalborg
Portland cement factory is a giant in com-
parison to all other energy consumers.
The increase in Aalborg Portland’s
energy consumption reflects an increase
in the production of cement.
As a result of its high energy consumption, Aalborg Portland refers directly
to the national Energy Agency, which
is why the local authority has no direct
influence on Aalborg Portland’s energy
consumption and emission of CO2.
15
The surplus heat that Aalborg Portland
supplies to the District Heating Utility
Company is not associated with additional fuel consumption. As a result,
therefore, the CO2 emission from the cement factory’s production of district heating is only included in Aalborg Portland’s
CO2 account and not in that of the District
Heating Utility Company.
The efficient utilisation of surplus heat
is a major reason why CO2 emission in
the rest of the municipality has fallen.
Outside the municipality’s urban
areas, the increased use of wood, straw
4.2
and natural gas as sources of heat has
also contributed to the reduction of CO2
emission. A number of small towns are
supplied with district heating from local,
natural gas-fired combined heat and
power plants, and in the countryside
many individually heated buildings have
converted from oil to gas as their chief
energy source.
Each household can reduce the CO2
emission stemming from the heating of
the dwelling by approximately 25% by
changing from an oil-fired burner to a
natural gas-fired burner.
CO2 emission in the Municipality of Aalborg
Mill. tonnes CO2
3
2
1
0
1990
2000
2010
CO2 emission, remainder of the Municipality of Aalborg
CO2 emission from Aalborg Portland as a result of energy consumption
CO2 emission in the Municipality of Aalborg excl. transport. (Source: Energy Balance for
the Municipality of Aalborg)
16
The highly efficient kilns at Aalborg Portland
produce large amounts of cement, from where
surplus heat for the District Heating Utility
Company originates. The industrial symbiosis
between Aalborg Portland and the Public Utility
Companies is of mutual benefit, both with regard
to the environment and in economic terms.
Photo: Aalborg Portland.
4.3
Municipality of Aalborg - buildings according to type of heating
40,000
35,000
Number of buldings
30,000
25,000
20,000
15,000
10,000
5,000
0
District/communal heating
Natural gas
Oil burner
Stove/other
Stove/electricity
Heat pump
No heating installation
Unknown
Buildings in the Municipality of Aalborg in 2002 broken down according to type of heating (Source: Register of buildings and housing (BBR) for the Municipality of Aalborg)
4.4
CO2 emission when heating a dwelling with a heating requirement of 75 GJ
7,000
6,000
kg CO2/year
5,000
4,000
3,000
2,000
1,000
0
Natural gas
Oil
CO2 emission when heating a single-family dwelling with an annual heating requirement of 75 GJ.
17
5. The Public Utility Companies’
supply of energy in Aalborg
As the major suppliers of district heating,
electricity and gas, the Public Utility
Companies play a decisive role in a
sustainable energy supply in the Municipality of Aalborg.
Three of the six Public Utility Companies are suppliers of energy. These are:
The District Heating Utility Company
The Electric Utility Company - AKE
Net
The Gas Utility Company
The District Heating Utility Company
has approximately 28,000 customers.
There are approximately 1,400 additional
customers supplied by the district heating
company Nørresundby Fjernvarme, which
purchases the heat wholesale from the
District Heating Utility Company.
The number of customers actually refers to the number of meters. For
example, a single customer may in fact
be a cooperative housing society - thus
equating to a much larger number of
individual consumers.
In overall terms, the number of customers supplied by the District Heating
Utility Company corresponds to a degree
of coverage of 96% in the current supply
area. The District Heating Utility Com18
pany - including Nørresundby Fjernvarme
– supplies 4,826 TJ per year (2002),
corresponding to 98% of the total district
heating consumption in the municipality and 82% of the total consumption of
room heating and domestic hot water in
the municipality.
AKE Net has approximately 59,000
customers. The supply area covers
central Aalborg and Nørresundby. AKE
Net supplies 927 GWh or 3,335 TJ per
year (2002), corresponding to 84% of
the total electricity consumption in the
municipality.
The Gas Utility Company has approximately 11,000 customers, the majority in
central Aalborg and Nørresundby, where
the gas is distributed through the town
gas network. Gas for cooking makes up a
relatively large proportion of the Gas Utility Company’s total supply of 4,296,000
m3 per year, corresponding to 83 TJ.
The Public Utility Companies’ share of the gross energy consumption
in the Municipality of Aalborg
5.1
The District Heating Utility Company
AKE Net
26%
48%
The Gas Utility Company
Other utility supply
1%
25%
The Public Utility Companies’ share of the gross energy consumption in the Municipality
of Aalborg in 2002, excl. Aalborg Portland (Source: Energy Balance for the Municipality
of Aalborg)
The three companies supply a total
of 8,244 TJ per year, which makes up
34% of the total net energy consumption – energy consumption excluding
losses associated with the production
and distribution of electricity and heat
– in the Municipality of Aalborg including
Aalborg Portland, or 86% of the total net
energy consumption excluding Aalborg
Portland.
All three companies are distribution
companies that are primarily responsible
for the distribution of energy – only
the District Heating Utility Company
produces energy itself in the form of
heat, and even then only to a very limited
extent. The public utilities’ contribution
to the promotion of sustainable utility
supply therefore falls within the following
three principal areas. The three Public
Utility Companies can:
1. purchase energy produced with
minimal environmental impact
2. try to limit customers’ energy consumption and impact on the environment
3. limit their own energy consumption
and impact on the environment
The way in which focus is applied and the
effect that it has depends on the type of
supply. For example, the District Heating
Utility Company has ample opportunity
to ensure minimal environmental impact
through cooperation with local producers
of surplus heat, whereas AKE Net only
distributes the electricity that customers
buy, including the statutory share of
electricity from windmills and combined
heat and power plants.
The gross energy consumption is an
indicator of how much fuel is used to
produce the energy that is supplied to the
consumers. The Public Utility Companies
account for three quarters of the gross
energy consumption in the Municipality
of Aalborg.
A number of tasks are performed jointly. For example, work on pipelines and
cables is coordinated and much of the
advice and guidance offered to customers
takes place through Energicenter Aalborg,
which is run jointly by the Public Utility
Companies and Naturgas Midt-Nord.
The Gas Utility Company, AKE Net and
the District Heating Utility Company draw
up DSM (Demand Side Management)
plans that aim to limit customers’ energy
consumption.
By means of IRP (Integrated Resource
Planning) the three companies also try
to limit their own energy consumption.
In addition, the three companies present
environmental accounts every year.
The Limfjord, here with the oil harbour and
Aalborg Portland in the background, means that
Aalborg is a busy port. Over the years, a large
percentage of the traffic has been transferred to
the East Harbour.
Photo: Ajs Smed Nielsen.
19
6. The District Heating Utility Company
The City of Aalborg is concentrating its
efforts on district heating that is primarily
produced as combined heat and power
and as surplus heat from industry. District
heating is thus extremely environmentally
friendly in comparison with individual
sources of heat that are based on fossil
fuels.
The district heating network is extremely well developed in all urban areas.
82% of all heated buildings in the municipality are today supplied with district
heating compared with 63% in 1990.
Within the supply area, 96% of the total
building area is connected to the District
Heating Utility Company. In six minor
urban areas heat is supplied from natural
gas-fired combined heat and power plants.
6.1
The District Heating Utility Company’s supply area
In central Nørresundby the District Heating Utility Company sells district heating wholesale to Nørresundby Fjernvarmeforsyning. The district is in practice a part of the supply
area and is regarded as such in this publication.
20
Large radiators provide an efficient way of drawing heat out of
district heating water and into the living room. District heating
in Aalborg is charged according to the number of cubic metres
of district heating water used by the customer. It is therefore up
to the customer himself to utilise the heat in the district heating
water in the best possible manner. Photo: Ajs Smed Nielsen
Producers of heat
Almost all heat within the District Heating
Utility Company’s supply area is supplied
by three main producers:
Aalborg Portland A/S – cement factory
I/S Reno-Nord – waste incineration
Elsam A/S, Nordjyllandsværket
– combined heat and power plant
Fuel consumption - Single-family dwelling
6.2
250
Fuel consumption GJ
200
150
100
50
0
District heating
Oil burner
Electric heating
Consumption of fuel for heating of a dwelling (75 GJ) with district heating, oil burner and
electric heating respectively. (Source: City of Aalborg, District Heating Utility Company,
Environmental Accounts 2002)
There are also a number of smaller
suppliers: The Sewage Utility Company’s
two central sewage treatment plants and
the District Heating Utility Company’s 10
central stations, which are primarily fired
with natural gas.
Surplus heat is CO2-neutral and therefore has the highest priority in the supply
of district heating. This means that as far
as possible Reno-Nord and Aalborg Portland supply all the heat that they produce,
whilst Nordjyllandsværket covers the
remaining heat requirements. The District
Heating Utility Company’s own central
stations act mainly as reserves.
The surplus heat produced at Aalborg
Portland is generated from the production of cement. Aalborg Portland is in the
process of increasing its capacity with
regard to the production of white cement,
after which the annual supply of heat
will rise from 1,400 TJ to 1,900 TJ from
2006, corresponding to almost 30% of
the District Heating Utility Company’s
purchase of heat.
The surplus heat from Reno-Nord
is generated from the incineration of
waste from Aalborg and a number
of other municipalities and refuse sup21
Customers’ energy consumption
When it comes to limiting CO2 emission as a result of heating, the principal
element of the District Heating Utility
Company’s strategy has been to acquire
as many customers as possible – due
to the modest CO2 emission per unit of
supplied heat in comparison with other
sources of heat.
As district heating is often also much
22
6.3
Pollution from a single-family dwelling
25
20
15
10
5
0
CO2 tonnes
District heating
SO2 kg
Oil burner
NOx kg
Electric heating
Emission of CO2, SO2, NOx as a result of heating a dwelling (75 GJ) with district heating,
oil burner and electric heating respectively. (Source: City of Aalborg, District Heating
Utility Company, Environmental Accounts 2002)
6.4
The District Heating Utility Company CO2/GJ
35
30
25
20
kg
pliers. Reno-Nord is currently increasing
its capacity such that the annual supply
of heat from 2006 is expected to be approximately 1,100 TJ.
At Nordjyllandsværket the heat is
produced in a new section that was commissioned in 1998 as a replacement for
the coal-fired combined heat and power
plant Nordkraft in Aalborg. This new section is the world’s most efficient coal-fired
power plant.
In a few suburban towns, the District
Heating Utility Company has acquired
decentralised natural gas-fired combined
heat and power plants during the last few
years.
Since surplus heat accounts for up to
half of the district heating in Aalborg, the
CO2 emission per energy unit supplied
to the District Heating Utility Company
is extremely low in relation to other
towns providing district heating to which
Aalborg would normally be compared.
Between 1990 and 2002, the level of
CO2/GJ for heat supplied from the District
Heating Utility Company fell by 36%.
Since the proportion of surplus heat will
increase in the future, the CO2 emission
is expected to fall even further as a result.
15
10
5
0
1990
1992
1994
1996
1998
2000
2002
CO2 per GJ resulting from the district heating sold by the District Heating Utility Company.
6.5
The District Heating Utility Company’s purchase of heat
7000
6000
5000
TJ
4000
3000
The use of GPS equipment
enables all pipelines in
Aalborg to be plotted with a
degree of precision that can
be measured in centimetres.
Gas pipes, district heating
pipes, water pipes, sewer pipes and electricity cables are
registered in this manner. The
positions of the pipes/cables
and other data are gathered
and collated in a geographical information system. This
data can be utilised when
coordinating repair and maintenance work on pipes.
Photo: Ajs Smed Nielsen
2000
1000
0
1990
2002
Nordkraft (decommissioned 1998)
2012
Eternit factory
Nordjyllandsværket
Sewage Treatment Plants, East & West
Reno Nord
Reserve, gas and gas oil
Aalborg Portland
The District Heating Utility Company’s purchase of heat in TJ from heat suppliers in
1990, 2002 and 2010 (Source: City of Aalborg, Public Utility Companies)
cheaper for the individual customer than,
for example, heat provided by an oil
burner, this strategy has been particularly
effective. The supply area has grown
and the percentage of customers that are
connected to the district heating network
within the supply area has also increased.
Today, practically all homes and businesses that are able to connect to the
district heating network have done so.
Overall, the connected area increased
from 7.9 million m2 in 1990 to 10.1
million m2 in 2002, corresponding to an
increase of 22%. This increase has oc-
curred despite the fact that a new method
has been introduced for the calculation of
commercial areas, which alone has meant
a reduction of some 616,000 m2.
The District Heating Utility Company’s
customers are charged according to the
number of cubic metres of hot water
used, and not according to how many
units of heat are used. It is therefore good
business for the individual customer to
extract as much heat from the district
heating water as possible before it is sent
back to the heat producers via the District
Heating Utility Company’s pipelines.
23
6.6
The District Heating Utility Company - Connection percentage
100
90
80
70
60
50
40
30
20
10
0
1990
1992
1994
1996
1998
2000
2002
Area connected to the District Heating Utility Company in percentage of total building
area within the supply area (Source: City of Aalborg, District Heating Utility Company)
Meter with a modem. The District Heating Utility
Company offers its customers the option of monitoring
their consumption around the clock via the telephone
network. Customers are notified immediately if their
consumption suddenly increases dramatically. The
difference between inlet and outlet temperatures is also
registered in order to make sure that customers utilise
their district heating in the optimum manner.
Photo: Ajs Smed Nielsen
24
A good cooling effect at consumers’
premises also benefits both the heat
producers and the District Heating Utility
Company. The average drop in temperature for 1 m3 of district heating water is
approximately 400 C when measured on a
yearly basis. If this cooling figure was only
200C, for example, a further 25 million m3
of district heating water – which would
mean almost twice the current volume
– would have to be sent through the
district heating network in order to achieve
the same output at consumers’ premises.
The lower the temperature of the return
water, the smaller the losses of heat during
transport back to the heat producers.
Smaller amounts of district heating water
mean less pumping is required.
Overall, good cooling of the district
heating water at consumers’ premises
results in huge energy and environmental
benefits. For this reason, the District Heating Utility Company makes a great effort to
provide advice on installations and insulation at its customers’ dwellings such that
the heat is utilised in the optimum manner.
This takes place in cooperation with private
plumbing firms and building contractors.
From 2005 onwards all customers will
have electronic meters, thus making it
easier to monitor consumption. Customers
also have the option of taking out a service
subscription according to which the
District Heating Utility Company can carry
out remote monitoring of consumption and
ensure that the heat is efficiently utilised,
and take corrective action in the event of
unintentional fluctuations in consumption.
An average family uses approximately
2.4 m3 district heating water per m2
The Public Utility Companies
in Aalborg are also active on
the Internet. At “Energihuset”
citizens can simulate their consumption of energy and water
in an ordinary dwelling and see
what effect any changes have
both on the environment and on
their private economy.
6.7
Realised heat savings
16,000
14,000
12,000
GJ
10,000
8,000
6,000
4,000
2,000
0
1995
1996
1997
1998
1999
2000
2001
2002
Realised heat savings as a result of the District Heating Utility Company’s business
consultancy services. (Source: Energicenter Aalborg)
residential area per year, corresponding
to 0.4 GJ district heating per m2 residential area per year. Approximately one
quarter to one third of the heat is used
for domestic hot water, whilst the rest
is used to heat up the premises. Almost
60% of the heat that the District Heating
Utility Company sold in 2002 was used in
private homes.
The District Heating Utility Company
makes a great effort to provide advice
and information to both customers and
business partners, in particular because
installations at consumers’ premises are
crucial for the efficiency of the utility supply. Since 1997 the District Heating Utility
Company has regularly drawn up DSM
plans (Demand Side Management) as a
strategic tool to create energy savings for
its customers.
25
6.8
Renovation and new construction of district heating pipelines
40
35
30
25
km
During the period 1995-2002 the District Heating Utility Company’s business
consultancy services resulted in savings
of no less than 47,841 GJ, which has led
to a total reduction in the emission of CO2
of 1,263 tonnes.
Furthermore, conversion from other
energy forms to district heating carried
out by the District Heating Utility Company’s business customers corresponds to
about 62,000 m3 or 10,500 GJ of district
heating.
The District Heating Utility Company’s advice and guidance in terms of
private households cannot be accurately
calculated.
20
15
10
5
0
1990
1992
1994
New construction
1996
1998
2000
2002
Renovated
The District Heating Utility Company’s annual renovation and new construction of district
heating pipelines (Source: City of Aalborg, District Heating Utility Company)
The district heating network in Aalborg
was established in the 1950s and has
since been extended such that today it
covers practically all major adjoining
urban areas in the municipality.
Photo: Ajs Smed Nielsen
6.9
The District Heating Utility Company - Total network loss
1,800
1,500
TJ
1,200
900
600
300
0
1990
1992
1994
1996
1998
2000
2002
The total actual network loss per year in the District Heating Utility Company’s supply
area, 1990 - 2002. (Source: City of Aalborg, District Heating Utility Company)
26
6.10
The District Heating Utility Company - Power consumption for pumping
2.5
MWh/TJ
2.0
1.5
1.0
0.5
0.0
1990
1992
1994
1996
1998
2000
2002
The District Heating Utility Company’s consumption of electricity for pumping, 1990 - 2002
(Source: City of Aalborg, District Heating Utility Company)
6.11
The District Heating Utility Company’s consumption of make-up water
250
200
m3/km
The District Heating Utility
Company’s own energy consumption
Heat losses in the supply network and
energy consumption for pumping operations are important factors for the District
Heating Utility Company’s own energy
consumption.
In Aalborg-Nørresundby the hot
water is distributed through a 1,200 km
long dual-line (supply and return lines)
network. In addition, there are a few km
of pipes associated with the decentralised
combined heat and power plants in small
suburban towns.
Heat loss in the pipes is limited in several ways. Since 1999 the District Heating
Utility Company has used pipes with
extra insulation when carrying out new
construction and renovation. The network
has been renovated systematically, and by
2008 it is expected that the entire network
will consist of modern, pre-insulated
district heating pipes.
The lower the temperature in the
network, the smaller the heat loss to the
surroundings. Since 1988 the supply
line temperature in the network has been
gradually reduced. Today the supply
temperature is regulated between 75°C
and 90°C depending on the outside
temperature.
Network losses have been reduced by
13% from 1990 to 2002 as a result of
pipeline renovation and low temperature
operation. During the same period 370
km of pipes were renovated. Network
losses in 2002 accounted for 21% of
the total heat production to the District
Heating Utility Company. In 2010 it is
150
100
50
0
1991
1993
1995
1997
1999
2001
The District Heating Utility Company’s consumption of make-up water per km district
heating pipe, 1991 – 2002. (Source: City of Aalborg, District heating Utility Company)
27
CO2 emission
The increasing proportion of surplus heat
and the focusing of efforts on consumer
energy savings and in connection with
the distribution of district heating water
have resulted in a reduction in the District
Heating Utility Company’s CO2 emission in spite of the fact that the supply
of district heating has increased. The
emission of both SO2 and NOX has also
fallen, which can be primarily attributed
to the new section at Nordjyllandsværket
that was commissioned in 1998.
During the next few years surplus heat
from Aalborg Portland and Reno-Nord
will account for an even bigger proportion
28
6.12
The District Heating Utility Company - CO2 emission
180
160
1,000 tonnes CO2
140
120
100
80
60
40
20
0
1990
1992
1994
1996
1998
2000
2002
CO2 emission in connection with district heating supplied, 1990-2002. (Source: City of
Aalborg, District Heating Utility Company)
6.13
The District Heating Utility Company - SO2 emission
1.200
1.000
800
Tonnes SO2
expected that relative network losses will
account for approximately 20% of the
total heat production to the District Heating Utility Company.
In parallel with the renovation of
pipelines, pumps with frequency converters have been installed so that the pumps
only run when needed. The resulting
savings in electricity have, however, been
offset by the increased power consumption of the pumps in conjunction with
the relocation of Elsam’s heat production
from the now decommissioned heat and
power plant at Nordkraft south of the fjord
to Nordjyllandsværket north of the fjord.
The high connection percentage
and thereby short distance between the
customers helps to minimise pumping in
relation to the amount of heat supplied.
Despite the continued growth of the
supply network, the consumption of
make-up water per km pipeline has fallen
steadily.
600
400
200
0
1990
1992
1994
1996
1998
2000
2002
SO2 emission in connection with district heating supplied, 1990-2002. (Source: City of
Aalborg, District Heating Utility Company)
As the Port of Aalborg’s terminal facilities have
been relocated to the East Harbour and the
aquatic environment in the Limfjord has improved, it has become more attractive to live on the
banks of the fjord. The picture shows Vestre Havnepromenade, which in recent years has been
developed with both residential housing and new
businesses. Photo: Ajs Smed Nielsen
6.14
The District Heating Utility Company – CO2 emission
160
140
1,000 tonnes CO2
120
100
80
60
40
20
0
1990
2002
of the district heating supplied. The emission of CO2, SO2 and NOX will therefore
fall even further. The District Heating Utility Company expects that the increased
amount of surplus heat in 2012 will lead
to a reduction in the emission of CO2 of
30,000 tonnes per year.
Moreover, the District Heating Utility
Company expects that energy savings on
the part of its customers and a restructuring of the remaining market will reduce
the total CO2 emission as a result of heat
consumption in the supply area by a
further 10,000 tonnes in 2012.
2012
CO2 i 1000 ton/år ??????
Emission of CO2 as a result of heat supplied in the District Heating Utility Company’s
supply area, 1990-2002, and target for 2012. (Source: City of Aalborg, District Heating
Utility Company)
29
Aalborg Portland, which is situated on the
eastern outskirts of Aalborg, covers an area
of 344 hectares, approximately half of which is
made up of Aalborg Portland’s chalk quarry. In
addition to the production plants themselves,
there are two internal dumping sites and a recycling site in the area. Photo: City of Aalborg.
30
Aalborg Portland
Aalborg Portland A/S is Denmark’s only
cement manufacturer and has an annual
production capacity of 2.8 million tonnes
of cement, of which approximately half is
exported to around 70 countries worldwide. Net turnover in 2002 was just under
DKK 1.5 billion.
Aalborg Portland, which is part of
Denmark’s biggest industrial group, FLS
Industries, is the world’s biggest exporter
of white cement. The enterprise is focusing its efforts on becoming the world’s
largest manufacturer within this area.
The cement is produced at highly
advanced production plants, and Aalborg
Portland devotes a lot of resources
to intensive research into enhancing
the cement’s properties and creating
improvements in the environmental and
energy area.
Cooperation with the Public Utility
Companies covers several areas of utility
supply. Aalborg Portland is Denmark’s
biggest consumer of electricity and
thereby also by far the Electric Utility
Company’s biggest customer. The factory
receives granulated sludge from the
Sewage Utility Company and discarded
furniture from the Refuse Collection Utility Company. Both of these products are
used in the production of cement.
Cooperation works both ways, as
can be seen by the significant amount
of district heating that Aalborg Portland
supplies to the District Heating Utility
Company.
31
7. The Electric Utility Company – AKE Net
The Jutland-Funen electricity network
is connected to the electricity grids in
Norway, Sweden and Germany. A large
number of foreign and Danish producers,
from small windmills to hydroelectric
power stations, large nuclear power plants
and coal power stations supply electricity
to the network.
In central Aalborg and Nørresundby,
AKE Net is the company responsible for
the distribution of electricity. AKE Net’s
core tasks are:
to operate and maintain the electric
utility networks up to and including
60 kV in the supply area
to supply prioritised energy – which
is electricity from windmills and decentralised combined heat and power
plants
7.1
The Electric Utility Company’s supply area
The Electric Utility Company’s supply area covers most of Aalborg and central Nørresundby, as well as the airport area.
32
7.2
to promote energy-saving activities
aimed at its customers.
Electricity sales, losses, and electricity saved
1,200
1,000
GWh
800
600
400
200
0
1991
1993
1995
1997
1999
2001
Heavy industry
Industry
Retail trade and service
Other
Household
Losses
Electricity saved
Consumption of electricity, grid losses and electricity saved in the Electric Utility Company AKE Net’s area (Source: City of Aalborg, Electric Utility Company - AKE Net)
Lights on the waterfront. As a result of the deregulation of the
electricity market, the Electric Utility Company’s former contracting department has been restructured and set up as an
independent limited company, AKE Entreprise, which has the
establishment and maintenance of outdoor lighting among its
core tasks. Photo: Ajs Smed Nielsen
In the remainder of the Municipality of
Aalborg, these tasks are carried out by
other electricity supply companies within
their respective supply areas. The high
voltage grid with voltages of 150 kV and
400 kV are operated by NV Net A.m.b.a
and Eltra A.m.b.a respectively.
AKE Net owns AKE Forsyning A/S and
AKE Entreprise A/S.
AKE Forsyning A/S is responsible for
the purchase and sale of other energy,
also called “market electricity”. AKE
Forsyning A/S is a local supply company
that has a duty to supply electricity to
those consumers within the supply area
who do not wish to exploit the deregulated electricity market. With a customer
share of more than 90%, AKE Forsyning
A/S is the dominant company in the
Aalborg-Nørresundby supply area.
AKE Entreprise A/S is responsible for
commercial services in competition with
other public and private contractors and
electricians, including operational and
service tasks such as traffic lights and
streetlights.
Electricity production
AKE Net does not have any direct
influence on pollution or consumption of
resources in the production of electricity.
AKE Net is, however, a co-owner of the
Jutland-Funen electricity production
company Elsam A/S, which as a producer
of electricity has a duty to follow the
objectives adopted by the Danish government and parliament.
33
Prioritised energy is electricity generated
by windmills and other CO2-neutral
energy sources and by decentralised
combined heat and power plants. Within
the Electricity Utility Company AKE Net’s
area, there is an annual production of 46
million kWh (2002) of prioritised energy
at Reno-Nord, industrial combined heat
and power plants and windmills.
During recent years Danish consumers
have had 40% of their electricity consumption charged as prioritised energy.
The obligation to purchase prioritised
energy is statutory and the proportion is
adjusted regularly. Wind energy accounts
for approximately one third of the total
amount of prioritised energy, and its
share continues to climb.
Customers’ consumption
During recent years electricity consumption has steadily increased. Trade and
industry, not least Denmark’s biggest
electricity consumer, Aalborg Portland,
is responsible for a large proportion of
this increase. The continued increase in
the number of electrical appliances in the
home also plays a role.
AKE Net’s most important direct influence on the reduction of CO2 emission is
to urge savings on the part of consumers.
34
7.3
Realised electricity savings
6,000
5,000
MWh
4,000
3,000
2,000
1,000
0
1994
1995
1996
1997
1998
1999
2000
2001
2002
Realised electricity savings as a result of AKE Net’s business consultancy services.
(Source: Energicenter Aalborg)
7.4
Reduction in CO2 emission
3,500
3,000
2,500
Tonnes
The most important means of reducing
CO2 emission in connection with the
production of electricity are:
to co-generate electricity and heat
to make electricity production more
efficient
to increase the proportion of renewable energy
2,000
1,500
1,000
500
0
1994
1995
1996
1997
1998
1999
2000
2001
2002
Reduction in CO2 emission as a result of AKE Net’s business consultancy services.
In autumn 2003 the last overhead cable
in AKE Net’s low voltage network was taken down. All electricity within the supply
area is now supplied through underground cables. Photo: City of Aalborg
7.5
AKE Net - CO2 emission
400
350
1000 tonnes
300
250
200
150
100
50
0
1990
2002
2012
Emission of CO2 as a result of electricity supplied within AKE Net’s supply area in 1990
and 2002, and target for 2012. (Source: City of Aalborg, Electric Utility Company - AKE
Net, Environmental accounts 2002)
Since 1995 AKE Net has regularly drawn
up DSM plans aimed at creating energy
savings on the part of its customers.
AKE Net provides free advice to its
customers, both through its own customer services department and through
Energicenter Aalborg. During the period
1994-2002 AKE Net’s business consultancy services resulted in total savings
of 29,185 MWh and a total reduction in
emission of CO2 of 17,450 tonnes. AKE
Net’s advice with regard to private households cannot be accurately calculated.
The Electric Utility Company’s own
consumption
As the distributor of electricity in central
Aalborg and Nørresundby, AKE Net’s primary efforts with regard to the reduction
of CO2 emission are focused on limiting
losses in the supply network. This is
achieved by the ongoing renovation of
transformer stations, cables and lines.
Losses in the supply network in
2002 stood at 24.9 GWh, which is less
than 3% of AKE Net’s total transport of
electricity.
CO2 emission
The increase in the number of windmills
and decentralised combined heat and
power plants and the decommissioning of
outdated power stations have resulted in
a considerable reduction in the emission
of CO2, SO2 and NOx stemming from the
production of the electricity that AKE Net
distributes to its customers. In addition,
AKE Net’s energy saving activities with
regard to its customers have resulted in
energy savings, and reduced emission
of CO2, SO2 and NOx from electricity
production as a consequence.
CO2 emission from the production of
the electricity that AKE Net distributes to
its customers is expected to be reduced
by 10% by 2012 – corresponding to
approximately 40,000 tonnes – in relation to today’s level due to the fact that
coal will be replaced by natural gas and
renewable energy.
Moreover, AKE Net expects that
customers will reduce their electricity
consumption in 2012 by approximately
30 GWh in relation to today. CO2 emission will thereby fall by approximately
15,000 tonnes.
It is assumed that electricity consumption will not increase as we approach
2012 due to other factors.
35
Nordjyllandsværket, which lies east of
Nørresundby, has a double role as one of
Denmark’s biggest producers of electricity
and Aalborg’s biggest producer of district
heating. Photo: Elsam
Foto
Nordjyllandsværket
36
Nordjyllandsværket
Nordjyllandsværket, which is situated
north of Aalborg, was built in 1967. It has
a power output of 665 MW and in 2002
produced 2,235 GWh (net) of electricity
and 3,801 TJ (net) of district heating. The
majority of the district heating is sold to
the City of Aalborg, District Heating Utility
Company, and a small amount to Gandrup-Vester Hassing Varmeforsyning in
the neighbouring municipality of Hals. The
power station employs 130 personnel.
There are two sections at the power
station. Section 2 is from 1977 and has
undergone continuous modernisation,
whilst section 3 is from 1998 and is the
world’s most efficient coal-fired plant.
Nordjyllandsværket uses coal and
heavy fuel oil in the production of
electricity and district heating. In addition, calcium and ammonia are used
to clean the flue gas and water is used
for the internal water/steam circuit, flue
gas cleaning and make-up water for the
district heating network. The flue gas is
cleaned so effectively that the emission of
SO2 is almost non-existent. The sulphur
that precipitates during cleaning is used
in cement production at Aalborg Portland.
37
8. The Gas Utility Company
Gas is a cleaner fuel than both coal and
oil. From a CO2 perspective it is therefore
important to promote the use of gas at the
expense of these two fuels.
The Gas Utility Company’s primary
task is to supply town gas to dwellings
and businesses in the central districts of
Aalborg-Nørresundby via a 190 km-long
pipeline supply network. Town gas is a
mixture of natural gas and atmospheric
air. Natural gas is supplied wholesale via
the regional natural gas network, after
which the Gas Utility Company produces
town gas itself, i.e. the process of mixing
the natural gas with compressed air.
The majority of the town gas supplied by the Gas Utility Company in the
8.1
The Gas Utility Company’s supply area
In the area marked, the Gas Utility Company supplies town gas through a 190 km
network of pipes. In the rest of the municipality gas is delivered in bottles.
38
Customers’ consumption
The Gas Utility Company devotes a great
deal of effort to persuading as many
consumers as possible to change from
an electric cooker to a gas cooker. This
is particularly true for catering kitchens
at institutions and companies, including
municipal kitchens. These efforts have
a great significance with regard to minimising CO2 emission. As part of these
efforts, the City Council has adopted an
environmental manual that makes the
use of gas for cooking compulsory when
carrying out urban renewal and building
non-profit rental housing.
In 2002 the Gas Utility Company sold
approximately 1 million m3 of town gas
for cooking, corresponding to almost
25% of total sales.
Since 1997 the Gas Utility Company
has regularly drawn up DSM plans.
During the period 1995-2002 the Gas
Utility Company’s business consultancy
services resulted in conversions from oil
and electricity to town gas, corresponding
to a total consumption of 2,093,625 m3.
CO2 emission has thereby fallen by 3,123
tonnes during the same period.
8.2
CO2 emission in connection with cooking
700
600
CO2 in kg
500
400
300
200
100
0
Solid plates
Ceramic
Induction
Gas
An average household’s annual CO2 emission in connection with cooking
(Source: City of Aalborg, Gas Utility Company)
8.3
Breakdown of consumption of gas
12
10
8
Mill. m3
centre of the city is used for cooking, as
the District Heating Utility Company is
responsible for the supply of almost all
heat in this area. A few areas are supplied
with natural gas, whilst in the rest of the
municipality the Gas Utility Company
delivers bottled gas to customers that are
not connected to the gas supply network.
In the year 2000, the Gas Utility Company was awarded environmental certification in accordance with ISO 14001.
6
4
2
0
1990
1992
1994
1996
Meter difference
Household
District heating
Other
1998
2000
2001
Business
Breakdown of the Gas Utility Company’s consumption of gas. (Source: City of Aalborg,
Gas Utility Company)
39
CO2 emission
The continued conversion of customers
from electricity to gas and the continued
reduction of pipeline losses are expected
to result in the Gas Utility Company’s
CO2 emission remaining largely stable at
current levels.
40
8.4
Realised town gas conversions
1,000,000
900,000
800,000
700,000
m3
600,000
500,000
400,000
300,000
200,000
100,000
0
1995
1996
1997
1998
1999
2000
2001
2002
Realised conversions as a result of the Gas Utility Company’s business consultancy
services. (Source: Energicenter Aalborg)
8.5
Reduction in CO2
1,600
1,400
1,200
1,000
Tonnes
The Gas Utility Company’s own
consumption
Town gas contains a lot of methane,
which is a greenhouse gas. Limiting
losses in pipelines is therefore a very important part of the Gas Utility Company’s
environmental efforts.
The best indicator of pipeline losses
is the meter difference, i.e. the difference
between the quantity of gas sent out into
the supply network and the quantity that
is charged for. The meter difference may
be due to circumstances such as leaks in
the pipeline network or losses in connection with repair work.
For many years the meter difference
has accounted for approximately 15%
of the total volume of gas. The goal is to
reduce the meter difference by 5% each
year. In recent years the Gas Utility Company has been close to achieving this
target, and the figure in 2002 was 4%.
The primary means of reducing the
meter difference include the ongoing
renovation of the pipeline network and
systematic localisation of leaks.
The second major item in the Gas Utility Company’s CO2 account is electricity
consumption, of which the vast majority
is used for compressing atmospheric air
to produce town gas. 1 m3 of natural gas
and 0.15 kWh of electricity are required to
produce 2 m3 of town gas.
800
600
400
200
0
1995
1996
1997
1998
1999
2000
2001
2002
Reduction in CO2 emission as a result of the Gas Utility Company’s business consultancy services. (Source: Energicenter Aalborg)
Restaurants and institutional kitchens
are among the Gas Utility Company’s
biggest customers. The use of gas rather
than electricity reduces CO2 emission
significantly. Photo: Aalborg Tourist &
Convention Bureau
41
Test a bulb. Energicenter Aalborg’s consultancy
services are aimed at both private households
and businesses, and include the free loan of
a suitcase with different types of low-energy
lightbulbs so that consumers can try them out for
themselves. Photo: Ajs Smed Nielsen
42
Energicenter Aalborg
A considerable part of the activities that
the Public Utility Companies perform
in order to persuade customers to save
energy and resources takes place through
Energicenter Aalborg.
Energicenter Aalborg was set up in
1993 and is run by the Public Utility Companies in collaboration with
Naturgas Midt-Nord. Energicenter
Aalborg provides advice to both private
households and business customers,
ranging from the smallest corner shop to
the biggest industrial group. This advice
encompasses everything from changing lightbulbs to advanced energy and
environmental management in energyintensive industrial enterprises.
Advice is provided on gas, electricity,
heat, water, waste water and solid waste.
Advice is provided free of charge and
its overall aim is to help the Public Utility
Company’s customers to utilise energy
and environmental resources in the optimum manner and thereby contribute to
the creation of a sustainable development
in the field of utility supply.
At the same time, the advice provided
helps both private and business customers to save money. Each year around
2,000 private individuals receive advice,
either directly or via the teaching of
schoolchildren.
The effect of advice and guidance to
private households cannot be calculated
precisely. The effect of consultancy
services provided to the business community can be calculated, however. Since
1993, Energicenter Aalborg has provided
consultancy services for around 500
companies within North Jutland with a
total consumption of:
•
•
•
•
150 million kWh town and natural gas
300 million kWh electricity
200 million kWh district heating
2 million m3 water
The companies in question have saved
an average of 10% on their energy and
water consumption for investments that
are repaid within a period of less than
four years.
When a company contacts Energicenter Aalborg, the typical procedure is
that, in collaboration with the company’s
own personnel, one of the centre’s experts
will chart the company’s consumption of
energy and environmental services.
The company will then receive a report
in which Energicenter Aalborg calculates
item-by-item the savings that can be
made and what they will mean in monetary terms. It is then up to the company
itself to decide which initiatives it wishes
to put into effect. In order to document
the effect, Energicenter Aalborg follows
up with measurements on the proposals
that are adopted.
Energicenter Aalborg is also able to
provide assistance when a company
wishes to receive additional services and
requires help in its quest to receive environmental certification, when drawing up
environmental accounts or establishing
a statutory energy management scheme.
Services of this nature must, however, be
paid for.
43
9. National goals and instruments for water and waste water
In 2003 Denmark incorporated the EU
Water Framework Directive from 2000
into national legislation. This means that
the protection of groundwater and surface
water are systematically considered
together for the first time.
The aim of the directive is to ensure
that all occurrences of water – lakes,
watercourses, groundwater reserves,
etc. – are in good condition, i.e. free of
9.1
pollution. In the case of groundwater, this
also means that it is prohibited to recover
water at a faster rate than it is created.
Surface water seeping down through
the soil has great significance for the
groundwater. In turn, the quantity and
quality of the groundwater is important
for the surface water, since the vast
majority of Danish watercourses are fed
by groundwater.
Price of water and waste water
30
25
DKK./m3
20
15
10
5
0
1990
1992
Price of water
1994
1996
Sewage charge
1998
2000
2002
VAT and duties
The development in the price of water, waste water and duties levied on customers of
the Water Utility Company and Sewage Utility Company in the period 1990 to 2002.
(Source: City of Aalborg, Public Utility Companies)
44
In Denmark almost all drinking water
comes from groundwater, which is sent
directly to consumers either untreated or
treated for naturally occurring substances
such as iron. Compared to the treatment
of surface water, this form of water supply
has advantages both in terms of operating
costs and ecology.
A great deal of the focus in Denmark
during the 1990s has therefore been
concentrated on designating areas of
particular interest with regard to drinking
water. Within these areas, the county
authorities have designated special action
areas in which particular efforts are made
to protect the groundwater, for instance
in the form of agreements concerning the
non-use of pesticides on arable land or
the acquisition of land for afforestation.
Outside these special action areas,
focus has been trained on the quality of
surface water, groundwater and wetlands.
Measures implemented to achieve this
include:
making the treatment of sewage more
effective (Since 1993, Danish statutory
requirements concerning the removal
of nitrogen, phosphor and organic
matter from sewage before discharge
have been more comprehensive than
prevailing EU requirements)
The continued use of untreated
groundwater as drinking water is a
primary objective of Danish environmental policy.
Photo: Tankegang a/s.
prohibiting or limiting the use of pesticides and other harmful substances
(In the government’s new “Pesticide
Plan 2004-2009” the goal is to reduce
the use of pesticides by 30% between
1999 and 2009)
increasing duties on fertilisers
providing financial support for sustainable land use
protecting, conserving and reestablishing wetlands, for example by
increasing the cultivation-free zones
alongside watercourses
developing new systems for testing
chemicals
9.2
The effective treatment of sewage is
ensured by modernising treatment plants
and developing new methods to eliminate
harmful substances. Systematic separate
sewer systems have limited the amount of
rainwater that the sewage treatment plants
have to process.
As a means of limiting water consumption, a statutory requirement has been introduced according to which water meters
must be installed in all properties. In addition, duties on both water and waste water
have increased significantly during recent
years. As a result of the above, and price
increases resulting from increased costs,
the consumption of water in Denmark has
fallen significantly since 1990.
Water consumption in Denmark
1,200
1,000
Mill. m3
800
600
400
200
0
1990
1992
1994
1996
1998
2000
Consumption of drinking water in Denmark (Source: Statistics Denmark)
45
10. Water and waste water in the Municipality of Aalborg
46
10.1
Water recovery in the Municipality of Aalborg
18
16
14
12
1000 m3
Water supply in the Municipality of
Aalborg is carried out by 53 private, nonprofit making waterworks and the local
authority’s own Water Utility Company.
Approximately 1,200 properties are supplied by their own recovery plants.
Since all inhabitants within the
Municipality of Aalborg are supplied with
drinking water in the form of groundwater
that is either untreated or only treated
for naturally occurring substances, the
crucial element in a sustainable local
supply is to protect the groundwater effectively in the areas in which it is created
and recovered.
In line with the increasing amount of
pollution, not least in urban areas, it has
been necessary to shut down a number of
water wells during recent decades.
Water recovery in the Municipality
of Aalborg takes place decentrally. This
helps to minimise the risk of excessive
pumping at a single location, which can
cause polluted surface water to seep
down into the groundwater more quickly.
The more slowly the water seeps down,
the better it is cleaned. The Water Utility
Company and private waterworks collaborate closely in the so-called Water
Plan Cooperation Agreement, which
consists of the following 3 elements:
10
8
6
4
2
0
1990
1992
1994
1996
City of Aalborg, Water Utility Company
1998
2000
2002
Private waterworks
Water recovery in the Municipality of Aalborg, 1990 - 2002. (Source: City of Aalborg,
Water Utility Company)
to ensure effective groundwater
protection in groundwater catchment
areas.
to ensure maximum reliability of supply through a reciprocally connected
pipeline supply network.
to make it possible for properties in
the open countryside to connect to the
public water supply at a reasonable
price.
All 3 elements are financed via charges
that are incorporated into the price of water. In the case of groundwater protection,
consumers pay DKK 0.40 per m3 water.
This money is used for initiatives such
as the acquisition of land in protected
groundwater catchment areas.
In the Aalborg region, the County of
North Jutland has the primary responsibility for drawing up action plans for
10.2
Average nitrate concentration
25
20
Nitrate content [mg/l]
areas of particular interest with regard to
drinking water. Based on the Water Plan
Cooperation Agreement, however, the
City of Aalborg has implemented a local
plan of action in the village of Drastrup,
which lies southwest of Aalborg. The plan
covers an area of 1.4 km2. Comprehensive restrictions have been implemented
with regard to how the land in this area
may be used. The area supplies water to
the western part of the city of Aalborg.
In 2005 it is expected that a similar
plan will be drawn up for a 17 km2-large
area southeast of Aalborg. Water wells
in the area supply water to central and
eastern Aalborg. Later, an area north
of Nørresundby is also expected to be
designated as a protected groundwater
catchment area.
Measurements taken by the Water
Utility Company in Drastrup since 1998
show that such restrictions do in fact
result in cleaner groundwater. Even in
an area that had been set-aside, where
the nitrate content in the groundwater
was low in comparison to the cultivated
areas, there was a rapid and significant
reduction such that the nitrate in the
groundwater had practically disappeared
after just one year.
One of the means of protecting the
groundwater catchment areas is to plant
forest. The municipality, which has
relatively little forest, can hereby increase
its contribution to the national goal of
20-25% of Denmark’s area being covered
by forest. An added benefit is the fact that
forests convert CO2.
15
10
5
0
23/4 98
23/4 99
Pasture area
23/4 00
23/4 01
23/4 02
23/4 03
Forest area
Nitrate content in groundwater – 1 m under the surface of the soil – in Drastrup local
action area in the period from April 1998 to December 2003. (Source: City of Aalborg,
Water Utility Company)
Green oasis. Effective sewerage ensures clean water even in the centre
of the city. Photo: City of Aalborg
47
Waste water
In the area of waste water, a concentration of activities has also taken place. A
number of small and relatively inefficient
sewage treatment plants have been
decommissioned, which has resulted in
about 98% of all sewage treatment being
carried out today at the Sewage Utility
Company’s two large sewage treatment
plants, Sewage Treatment Plant East (in
operation since 1975) and Sewage Treatment Plant West (1982) in Aalborg. From
2007 these two plants alone will service
a total of 200,000 inhabitants in Aalborg
and three neighbouring municipalities.
In line with the concentration on
the two large treatment plants, the
sewer network has been expanded. Since
around 1970, all new neighbourhoods in
towns within the municipality have been
established with separate sewer systems.
The separate drainage of rainwater has
helped to limit the increase in the volume
of waste water flowing to the two sewage
treatment plants.
Both initiatives have contributed to
a marked improvement in the quality of
surface water in both the Limfjord and
local watercourses. This is due in part
because treatment of the sewage is much
more efficient at the two large plants
than at small plants, and in part because
the direct discharge of effluents into
watercourses has been limited as a result
of more properties being connected to the
sewer system.
In addition to the 2,000 km-long sewer
network belonging to the City of Aalborg
Sewage Utility Company, there are around
4,000 km of private sewers in the Mu48
nicipality of Aalborg. Furthermore, almost
1,000 km of public and private sewers in
the municipalities of Støvring, Skørping
and Sejlflod are connected to the Sewage
Utility Company’s sewer network.
For properties in the open countryside
that are not connected to the sewer system, monitoring of the discharge of waste
water has been tightened up.
The County of North Jutland, which
monitors the water quality in watercourses in collaboration with the Sewage Utility
Company, has designated five action
areas in the Municipality of Aalborg – two
south and three north of the fjord – where
there is a need for better treatment of
waste water if the quality of the water
in watercourses is to be safeguarded.
Properties within these areas can be
ordered by the local authority to improve
waste water treatment. If a property cannot be connected to the sewer network,
the owner can choose to upgrade his
sewage treatment plant himself or permit
the Sewage Utility Company to do it for a
connection fee.
The concentration of sewage treatment
plants means that new methods of treatment can be put into service relatively
easily. Once again, the effect of this can
be seen by the fact that the water quality
in the Limfjord has improved markedly
within recent decades.
View of the future. Only a few years ago
Aalborg’s business community was based on
large, heavy industrial enterprises. Today it is
the knowledge industry that provides the driving
force. Within the field of communications technology, Aalborg has developed into an international
power centre. The picture shows Siemens’ premises in Lindholm on the former site of a cement
manufacturing plant. Photo: Ajs Smed Nielsen
49
11. The Water Utility Company
In line with the increasing amount of
pollution, a number of waterworks both
inside and outside the central city area
have been closed. The same applies
to many wells, typically on agricultural
properties. There is a tendency for the
water supply – both in terms of recovery
and distribution – to be concentrated in
fewer, but larger, units.
With the exception of a few districts,
the central area of the city is supplied
by the municipal Water Utility Company,
which is responsible for about 60% of
the water supply in the municipality. The
water is recovered from three large areas
just outside the city: Drastrup, Southeast
and Hvorup.
Both north and south of the fjord
a recovery capacity to cover normal
11.1
The Water Utility Company’s supply area
The Water Utility Company supplies the whole of Aalborg and central Nørresundby
with water.
50
Customers’ water consumption
The Water Utility Company has a few, limited possibilities for directly influencing
its customers’ consumption of water. In
this case, the government’s tax and duty
policy plays the central role. However,
the price of water has risen as a result of
increased costs associated with recovery
and distribution, which in itself may be
assumed to have put downward pressure
on consumption.
The Water Utility Company does a
great deal of work educating consumers
on how to save water. This takes place in
collaboration with Energicenter Aalborg.
The Water Utility Company is also
focusing efforts on making the use of individual water meters more widespread in
apartments in blocks of flats. Experience
has shown that consumption falls when it
is metered and charged individually.
The Water Utility Company’s consultancy services are aimed at both private
households and businesses. Energicenter Aalborg has calculated the effect of
consultancy to the business community.
11.2
The Water Utility Company - Price of water and duties
14
12
DKK./m3
10
8
6
4
2
0
1990
1992
1994
3
Price per m water
1996
1998
2000
2002
Duty levied on water and VAT
Development in prices and duties per m3 water, 1990 - 2002. (Source: City of Aalborg,
Water Utility Company)
11.3
Realised water savings
100,000
90,000
80,000
70,000
60,000
m3
consumption must be maintained. In addition, there must be a reserve capacity of
25% that can be used in emergencies, for
example if a source has to be temporarily
taken out of service. In order to ensure
sufficient capacity, the Water Utility
Company is examining the possibility of
establishing one or more new groundwater catchment areas south of Aalborg.
In the Municipality of Aalborg, there is
in general enough water below ground to
cover the current need for water recovery.
50,000
40,000
30,000
20,000
10,000
0
1995
1996
1997
1998
1999
2000
2001
2002
Realised water savings as a result of the Water Utility Company’s business consultancy
services. (Source: Energicenter Aalborg)
51
52
Reduction in CO2
25
20
Tonnes
The Water Utility Company’s own
consumption
Limiting the losses in pipelines is
the most important goal for the Water
Utility Company when it comes to its own
consumption. During the last four years
the Water Utility Company has renovated
approximately 25 km of mains pipes and
service pipes in its efforts to limit losses.
In 1991 the so-called unmetered water
consumption was 1.06 million m3. By
2002 this figure had been halved to 0.52
million m3 despite the expansion of the
supply network. The large fluctuations
from year to year in unmetered consumption are due to staggered charges or
the flushing of pipes in connection with
renovation work or pollution.
The pipeline network has grown as
a result of the Water Utility Company
acquiring a number of private waterworks. The transport distance between the
catchment areas and the consumers has
increased as a result of the relocation of
wells from the central city area.
The Water Utility Company’s consumption of electricity for pumping stands at
approximately 3 million kWh per year,
corresponding to the total consumption of
approximately 700 ordinary households.
Both the losses in the pipeline network
and the development in electricity consumption should be seen in light of the
growth of the pipeline supply network.
11.4
15
10
5
0
1995
1996
1997
1998
1999
2000
2001
2002
Reduction in CO2 emission as a result of the Water Utility Company’s business consultancy services. (Source: Energicenter Aalborg)
11.5
The Water Utility Company - Unmetered water consumption
14
12
10
8
%
During the period 1995-2002 a total of
168,814 m3 of water was saved.
As an added benefit, lower electricity
consumption for pumping operations has
reduced CO2 emission by 68 tonnes.
6
4
2
0
1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
Unmetered water consumption in percentage of the total water recovery, 1991 - 2002.
(Source: City of Aalborg, Water Utility Company)
Clean water costs money. For every litre of water
in the bath, the consumer pays 0.04 øre towards
groundwater cooperation in the Municipality of
Aalborg. Photo: Ajs Smed Nielsen
11.6
The Water Utility Company’s electricity consumption for pumping
3,500
3,000
1,000 kWh
2,500
2,000
1,500
1,000
500
0
1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
There are two further potential causes
of increased electricity consumption.
Firstly, it may be necessary to pump large
amounts of water away from sources that
are no longer used in order to maintain
the groundwater level, and secondly it
may be necessary to pump the upper
level of groundwater away in order to
prevent pollution of a source.
Conversely, the general fall in water
consumption has reduced the need for
pumping. The Water Utility Company
systematically uses energy-efficient
pumps when renovating existing plant or
establishing new plant.
The Water Utility Company’s electricity consumption for pumping, 1990 - 2002. (Source:
City of Aalborg, Water Utility Company)
53
12. The Sewage Utility Company
The Sewage Utility Company’s overall goal is to achieve a clean aquatic
environment in the municipality’s brooks,
streams, lakes and the Limfjord by means
of the recovery, transport and treatment of
waste water.
By the end of 2006 at the latest, the
Sewage Utility Company will accumulate
all sewage treatment at the two large
treatment plants, Sewage Treatment
Plant East and Sewage Treatment Plant
West. This is being carried out in order
to ensure maximum quality in sewage
treatment, which is in turn crucial for
the quality of the water in the region’s
watercourses and the Limfjord.
Today the vast majority of waste water
is treated mechanically, biologically
12.1
The Sewage Utility Company’s overall sewer network
Sewage Treatment Plants East and West with overall sewer network. (Source: City of
Aalborg, Sewage Utility Company)
54
12.2
The Sewage Utility Company - Quantities of treated waste water
40
35
30
1000 m3
25
20
15
10
5
0
1990
1992
1994
1996
1998
2000
2002
Quantities of treated waste water in m3, 1990 - 2002. (Source: City of Aalborg, Sewage
Utility Company)
Treatment efficiency
100
1000
95
800
90
600
85
400
80
1998
1999
2000
2001
B15
Total phosphor
Total nitrogen
Precipitation
2002
mm precipitation
12.3
%
and chemically, the latter, however, only
to a very limited extent as a means of
removing some of the phosphor content.
The Sewage Utility Company is working
towards treating as much of the sewage
as possible biologically.
Sewage treatment is particularly aimed
at removing organic matter, phosphor and
nitrogen from the waste water before it is
released into the Limfjord. The quantity
of a given substance that is removed by
treatment is called the treatment efficiency. The Sewage Utility Company’s target
is a treatment efficiency of at least 95%
for organic matter, 90% for phosphor and
80% for nitrogen.
The figures for treatment efficiency
fluctuate not only according to the content of the waste water, but also depend
on the amount of precipitation. In long
periods with heavy rainfall, the intake
of waste water to the sewage treatment
plants can exceed their capacity, as a
result of which elements of the treatment
process have to be restricted. Treatment
efficiency for nitrogen and phosphor is
particularly important, as these nutrient
salts can cause oxygen depletion.
In 1989 Sewage Treatment Plants East
and West were upgraded to enable the
removal of nutrient salts, i.e. phosphor
and nitrogen. This led to a considerable increase in the amount of sludge.
Through the use of discharge permits,
however, the local authority simultaneously demanded that companies should
eliminate heavy metals in their effluent
discharge, and thus this sludge could be
used in agriculture without any problem.
200
Treatment efficiency for organic matter, phosphor and precipitation, 1998 - 2002.
(Source: City of Aalborg, Sewage Utility Company)
55
The Sewage Utility Company’s own
consumption
The Sewage Utility Company’s consumption of electricity has risen in recent
56
12.4
Sewage Treatment Plant West - heavy metals in sludge
5,000
4,500
mg/kg phosphor
4,000
3,500
3,000
2,500
2,000
1,500
1,000
500
0
1992
Cadmium
1994
Mercury
1996
Lead
1998
2000
2002
Nickel
Content of heavy metals in sludge from Sewage Treatment Plant West, 1992 - 2002.
(Source: City of Aalborg, Sewage Utility Company).
12.5
Sewage Treatment Plant East - heavy metals in sludge
4,500
4,000
3,500
mg/kg phosphor
The quantity of sludge has been reduced from 30,000 tonnes per year in the
1990s to less than 5,000 tonnes in 2002.
This has been achieved by utilising the
organic matter to an increasing extent in
the production of biogas and by reducing
the water content in the sludge.
From the year 2000 onwards, all sludge
from both sewage treatment plants, East
and West, was accumulated and dried at
a special plant at East. The dried sludge
granulate is sold to the cement factory at
Aalborg Portland, where it is used both as
an ingredient in the cement itself and as
fuel in the production of cement.
The Sewage Utility Company’s 2,000
km main sewer network is continuously being renovated, in part in order
to reduce the quantity of groundwater
that seeps in. Along with separate sewer
systems and overflow facilities this has
reduced the quantity of water that places
an unnecessary burden on the sewage
treatment plants.
Leak-tight sewers reduce the seepage
of groundwater into the sewage system
and the waste water leaking out, and help
to discourage rats. Via regular TV inspections and computer models, the correct
dimensioning of the pipes is ensured.
This is particularly important in areas
with a communal sewer system, where
it reduces the risk of flooding in cellars
and the amount of overflow water that is
discharged into the aquatic environment.
3,000
2,500
2,000
1,500
1,000
500
0
1992
Cadmium
1994
Mercury
1996
Lead
1998
2000
2002
Nickel
Content of heavy metals in sludge from Sewage Treatment Plant East, 1992 - 2002.
(Source: City of Aalborg, Sewage Utility Company).
Attractive architecture and a functional
layout form a synthesis at the Sewage
Utility Company’s pumping station at Vestre
Promenade. Photo: City of Aalborg
12.6
Electricity consumption
16,000
14,000
12,000
10,000
KWh
years. The increase was particularly great
in 2000, when the sludge drying plant at
Sewage Treatment Plant East was commissioned.
In spite of the expansion of the sewer
network, the consumption of electricity
for pumping has fallen in recent years
due to the systematic use of energyefficient pumps. The Sewage Utility
Company currently operates 108 pumping stations.
The Sewage Utility Company utilises
the organic matter in the waste water to
produce biogas. At the Sewage Treatment
Plant West the gas is used to produce
electricity, which in 2002 corresponded to
57% of the plant’s own consumption. At
the Sewage Treatment Plant East the gas
is used as fuel in the sludge drying plant.
The surplus heat from both processes is
led out into the district heating network
when not being used to heat the sewage
treatment plants’ own buildings and
processing tanks.
The treatment of waste water is now so
effective that the sewage treatment plants
can use the treated water for mixing
chemicals and cleaning. The consumption of drinking water at the plants has
fallen correspondingly. In 2002, 10,000
m3 of drinking water was replaced by
treated waste water, corresponding to
the consumption of 70-80 single-family
dwellings.
8,000
6,000
4,000
2,000
0
1998
1999
2000
2001
2002
Sewage Treatment Plant West
Sewage Treatment Plant East
Other plants
Pumping stations
The Sewage Utility Company’s electricity consumption in the period 1998 to 2002,
broken down into Sewage Treatment Plant East, Sewage Treatment Plant West, other
plants and pumping stations. (Source: City of Aalborg, Sewage Utility Company)
57
13. National goals and instruments for waste
21%
54%
Legislation governing refuse and waste
in Denmark comes into effect in a close
interaction with the EU. The EU lays down
the overall framework, whilst the Danish
government and the Danish parliament
decide how the area should be organised.
This takes place through a combination of
legislation, duties, charges and systems
of subsidy.
The local authorities are responsible for
ensuring that the waste, both from private
households and businesses, is handled
correctly. Local authorities have a duty to
provide advice and guidance with regard to
the disposal of waste that is not collected.
The EU Waste Framework Directive
specifies a hierarchy for the handling of
waste:
Prevention. The less waste, the better.
Recycling. The more waste that can be
recycled, the better.
Incineration. As much as possible
of the waste that cannot be recycled
must be utilised to generate power
and heat.
Disposal. The less waste that has to be
disposed of at landfill sites, the better.
In Denmark these principles have resulted
in consolidated legislation on waste and
the government’s Waste Strategy 20052008.
58
A wide range of measures have been
employed in order to reduce the quantity
of waste, from duties on packaging to
consultancy services provided to business enterprises. Construction waste
accounts for a significant portion (33%
in 2002) of the total quantity of waste.
The building and construction sector is
subject to a number of standards that aim
to increase the proportion of environmentally-friendly materials and materials with
long lifetimes.
Danish efforts have hitherto concentrated on maximising the proportion of recyclable waste, minimising the proportion
for disposal on landfill sites, and utilising
combustible waste in the production of
energy. The sorting of waste at source is
therefore a crucial element in the Danish
system of waste management.
Some of the waste constitutes such a
health or environmental risk that it has
to be specially treated before it can be
used for recycling, incineration or landfill
disposal. This applies to items such as
electronic components, chemicals, batteries and accumulators.
Plastic is also a special area of focus
in which the goal is to increase the
degree of recycling. Today the majority of
plastic is burned in incineration plants.
13.1 Goals for waste management
25%
21%
2000
54%
25%
12%
24%
64%
12%
2004
24%
64%
9%
9%
26%
65%
26%
65%
Genanvendelse i %
Recycling
in %
2008
Forbrænding i %
Incineration in %
Deponering i %
Landfill disposal in %
Overall goals for waste management until 2008
(Source: Waste Strategy 2005-2008)
Electronic and electrical waste belong to
the group of waste products that require
special treatment before being sent for
recycling, incineration or disposal at a
landfill site.
Photo: City of Aalborg
59
14. Waste in the Municipality of Aalborg
Recycling
Waste from businesses makes up 84%
(2002) of the total quantity of waste.
Approximately half of the industrial waste
consists of earth and building materials,
of which the vast majority can be recycled. At several places in Aalborg special
sites have been set up for the temporary
disposal of this waste. Volumes have increased as a result of the building boom
in the 1990s.
Paper and cardboard from private
households are currently the focus of a
special initiative. The local authority is
working towards a recycling rate of 55%,
which is also the national target. One
of the means of achieving this involves
setting up containers for the collection of
paper and glass at blocks of flats and in
public places.
Combustible waste
Almost all combustible waste is used
in the generation of heat and electricity
60
14.1
Business and household waste in the Municipality of Aalborg
700,000
600,000
500,000
Tonnes
The City of Aalborg’s Waste Plan 20002012 is in line with the national goals with
regard to the sorting of waste at source,
maximising recycling, minimising landfill
disposal and utilising combustible waste
for the production of energy
400,000
300,000
200,000
100,000
0
1995
1996
Total recycling
1997
1998
1999
Total incineration
2000
2001
2002
Total landfill disposal
Business and household waste in the Municipality of Aalborg broken down into
recycling, incineration and landfill disposal. (Source: City of Aalborg, Refuse Collection
Utility Company)
at the incineration plant at Reno-Nord,
which the City of Aalborg co-owns with
six other local authorities in the region. In
2005 Reno-Nord will be commissioning a
new kiln line that will increase the annual
capacity to approximately 160,000 tonnes
of waste. The new plant will replace two
older kilns and have an efficiency of 98%.
The plant will be able to supply heat to
30,000 single-family dwellings and electricity to 16,000 single-family dwellings.
Landfill waste
All waste from Aalborg that cannot be
recycled or incinerated is deposited either
at the controlled landfill site in Rærup,
which is operated by Reno-Nord, or at
the Refuse Collection Utility Company’s
Waste and Recycling Centre in Rørdal.
Impregnated timber and other building
materials, plus sand and sludge make up
the largest groups of waste.
Hazardous waste
Hazardous waste such as oil and chemical waste and clinical risk waste is kept
separate from other types of waste and
requires special treatment prior to recycling, incineration or landfill disposal.
Of the 569,000 tonnes of waste,
475,000 tonnes come from business
and industry and the rest from private
households.
14.2 Business waste
14.3 Household waste
Husholdningsaffald
Husholdningsaffald
Erhvervsaffald
Erhvervsaffald
11%
11%
3%
11%
3%
11%
39%
58%
78%
78%
Recycling
Recycling
Incineration Incineration
Landfill
Landfill
Recycling, incineration and landfill
disposal of business waste in 2002.
(Source: City of Aalborg, Refuse Collection Utility Company)
39%
58%
Recycling
Recycling
Incineration Incineration
Landfill
Landfill
Recycling, incineration and landfill
disposal of household waste in 2002.
(Source: City of Aalborg, Refuse Collection Utility Company)
Cardboard and paper put into the recycling container. The City of Aalborg’s
goal is to recycle 55% of paper waste.
Photo: Ajs Smed Nielsen
61
15. The Refuse Collection Utility Company
The Refuse Collection Utility Company
handles approximately 17% of the waste
that is produced in Aalborg. The rest is
dealt with by private firms.
Household waste
The Refuse Collection Utility Company
collects and processes waste from all private households within the Municipality
of Aalborg. In two of the three districts,
however, the actual collection has
been contracted out to private haulage
contractors.
For several types of waste, special
collection systems have been set up. 11
times a year the Refuse Collection Utility
Company carries out pavement collections of bulky waste, paper and metal
from private households. Paper and glass
can also be disposed of in containers set
up at central locations. There are around
1,800 containers for paper and about 500
for glass.
Environmentally hazardous waste – for
example, paint, oil, chemicals, batteries
and drug residues – can be delivered to
a special van, “Rappenskralden”, which
comes to each local area twice a year.
Some types of hazardous waste are also
accepted by retail businesses such as paint
dealers, supermarkets and chemists.
15.1
The Refuse Collection Utility Company
owns and operates two recycling sites
in Aalborg and Nørresundby respectively, where local citizens can dispose
of all types of waste. The recycling sites
are very popular. The vast majority of
the waste that is delivered here can be
recycled.
The Refuse Collection Utility Company
owns and operates the Waste and Recycling Centre Rørdal, which functions as
a filling site, soil depot and composting
plant for garden and park waste.
Quantities of waste delivered to recycling sites
50,000
Tonnes
40,000
30,000
20,000
10,000
0
1990
Over Kæret
2002
Lindholm/Sundsholmen
Quantities of waste delivered to the Refuse Collection Utility Company’s recycling sites
in 1990 and 2002 respectively. (Source: Refuse Collection Utility Company)
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15.2
Clean exhaust, clean city. Since summer 2003
the Refuse Collection Utility Company has been
involved in a trial, the aim of which is to reduce
the quantity of soot particles in the exhaust gas
emitted from the company’s refuse collection
trucks. 6 trucks have been fitted with a newly
developed technical device, Octiboost, which
enhances the engine’s combustion of fuel.
Photo: City of Aalborg
Quantity of waste subject to advice
6,000
5,000
Tonnes
4,000
3,000
2,000
1,000
0
1997
1998
1999
2000
2001
2002
Quantity of waste for which advice has been given as a result of Energicenter Aalborg’s
business consultancy services. (Source: Energicenter Aalborg)
Industrial waste
The Refuse Collection Utility Company
collects all daily refuse from businesses. In addition, the Refuse Collection
Utility Company has a duty to provide
advice and guidance with regard to the
remaining waste – i.e. to provide advice
to companies on how to dispose of their
waste correctly.
During the period 1998-2002,
Energicenter Aalborg provided advice
and guidance covering a total of 10,900
tonnes of waste.
In its role as the municipal authority,
the Refuse Collection Utility Company
can demand that companies ensure that
their waste is disposed of correctly.
When it comes to the handling of
industrial waste that is not covered by a
collection scheme, the Refuse Collection
Utility Company competes on an equal
footing with other refuse contractors. A
company is thus free to choose whether
it wishes to use the Refuse Collection
Utility Company or another company to
handle its waste.
63
In the kilns at Reno-Nord incineration plant
in the east of Aalborg, solid waste is converted into electricity and district heating.
Photo: Ajs Smed Nielsen
64
I/S Reno-Nord
I/S Reno-Nord is a joint municipal waste
processing company that is owned by the
local authorities in Arden, Dronninglund,
Hals, Sejlflod, Skørping, Aabybro and
Aalborg. One of the company’s objectives
is to ensure that combustible waste from
the co-owning municipalities can be
incinerated.
The amount of waste for incineration at the plant from the 7 municipalities increased from approx. 110,000
tonnes/year to 135,000 tonnes/year
between 1995-1999, before falling to
127,000 tonnes/year in 2001. A further
12,000 tonnes of waste came from other
municipalities in 2001.
Reno-Nord currently has three kilns for
the incineration of waste. The two oldest
kilns were constructed in 1980, and
have a capacity of 8 tonnes of waste per
hour. These kilns, which produce district
heating, are today regarded as being out
of date. The third kiln was commissioned
in 1991 and has a capacity of 12.5 tonnes
of waste per hour, and supplies steam
to a combined heat and power plant that
generates both electricity and district
heating.
In 2002, Reno-Nord’s incineration
plant supplied a total of 978 TJ of heat
to the District Heating Utility Company
in Aalborg and 43 GWh to the electricity
grid.
Before the end of 2005 it is expected
that the three kilns described above will
be replaced by a new kiln for the incineration of waste. The reason for constructing
a new kiln is two-fold: firstly, that the
old kilns are worn-out and will require
considerable resources to be spent on
renovation, and secondly that the EU has
approved a new directive on air pollution
from incineration plants, which will also
result in heavy costs for improved cleaning of the flue gas on the old plant.
When the new kiln is commissioned in
2005, the two oldest ovens will be taken
out of service and the kiln that was built
in 1991 will be used as a reserve.
Following the commissioning of the
new kiln, the whole waste incineration
plant will have a total thermal capacity
of 66.7 MW, which means that the plant
will be able to burn more than 160,000
tonnes of waste per year.
In addition to the operation of the
waste incineration plant, Reno-Nord is
also responsible for a controlled landfill
site and a concrete-crushing plant, as
well as for the reception and treatment of
electronic scrap materials and refrigerator
and freezer appliances.
65
66
Clearer waters. Life in the Limfjord around
Aalborg is now flourishing once again thanks
to continued improvements in the treatment of
waste water. Photo: Dan Kaasby
THE PUBLIC UTILITY COMPANIES
Stigsborg Brygge 5
9400 Nørresundby
www.aalborg.dk/forsyning
[email protected]
CITY OF AALBORG