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Renewable energy in Denmark
WREC 1996
RENEWABLE ENERGY IN DENMARK IBEN OSTERGAARD
Renewable Energy Information Centre, Danish Technological Institute, P.O. Box 141, DK-2630 Taastrup, Denmark.
ABSTRACT About 7-8% of the primary energy consumption was covered by renewable energy by the end of 1995. There are difficulties in reaching the overall CO+duction goals and renewable energy sources should therefore hopefully bear some of the brunt The paper deals with the status and perspectives of exploiting wind energy, biomass, and solar energy.
KEYWORDS Renewable energy in Denmark, wind energy, biomass, solar energy.
Renewable enema. In the plan of action, “ENERGY 2500”, drawn up by the Danish Miistry of Energy in 1990, the objective for 2005 is that 10% of the primary energy consumption should be covered by renewable energy. About 7-896 of the primary energy consumption was covered by renewable energy by the end of 1995, so for the renewable energy part there do not seem to be any problems. However, there are great difficulties in reaching the overall CO,-reduction goals in the plan of action: reduction of CO2-emission by at least 20%. and renewable energy sources should therefore hopefully bear some of the brunt
WIND ENERGY Denmark is a windy country and we have a tradition for exploiting the wind. At present, there are about 3,860 wind turbines in Denmark with a capacity of approximately 637 MW. About half of the wind turbine capacity which has been installed world-wide during recent years is Danish and over half of the wind turbines around the world were produced in Denmark. The wind turbines in Denmark produced about 1.2 biion kWh in 1995 and thus saved the environment from approximately 1.2 million metric tons of CO,. It is realistic to assume that
1108
WREC 1996 wind power alone can contribute about 20% of the total CQ- reduction by letting 10% of Denmark’s electricity consumption be delivered by wind turbines with a capacity of 1500 MW. This is the capacity which the Danish energy plan assumes wiIl be established in Denmark by the year 2005, cotresponding to an annual enlargement amounting to 80-100 MW. During recent years only 30-75 MW have been achieved per year. This is due to several reasons such as: difficulties regarding siting, decmase in the payment for the electricity, limited possibilities for private people to invest in wind energy. However, in 1995 a satisfactory 98 MW were achieved. The growth in the use of wind energy in Denmark is to a high degtee based on private initiative and enthusiasm. Approximately 70% of the wind turbine capacity in Denmark is owned by private inividuals, whilst the remainder is owned by the electricity utilities. Nowadays, it is most common for a large wind turbine to be owned by a community - a so-called wind turbine guild. A wind turbine with an annual production of 500,000 kWh will have about 60 households as its owners. The electricity is sold to the local electricity utility, and the overall price including CO,-duty and energy duty refund, typically DKK 0.50-0.60 per kWh is achieved. There are about 8 Danish producers of type-approved wind turbines. The Danish wind turbine manufacturers export by far the greatest part of their production, namely approximately 479 MW out of a total on 577 MW in 1995. The wind turbine trade employs about 1,600 persons directly and about 8,500 persons when subsuppliers am included. The Danish electricity utilities have mainly developed large scale wind turbines - the newest one is a 1 MW turbine put into operation in 1993. Since 1985 the utility companies have also added commercial wind turbines in two 100 MW programmes and it is the intention of the energy plan that the electricity utilities will still play an active role in the development of wind energy.
BIOMASS Biomass comprises natural resources consisting of straw, manure from farms, wood chips and wood, organic waste from households and industries. Biomass is a very significant resource and it covers 80% of the energy supply from renewable energy sources in Denmark. In 1995 biomass covered about 5% of the primary energy consumption. In Denmark it was in connection with the oil crises in the seventies that the new era for the exploitation of biomass was opened. It was the shortage of oil and increasing oil prices that led to attempts to diversify the energy supply in Denmark. It was a decentralized implementation of the use of biomass as thousands of people re-installed some kind of wood-fired oven leading to important economizing on imported oil.
Wood and straw Wood and straw make up far the largest part of biomass exploitation in Denmark. The so-called “Biomass-agreement” drawn up by the Danish government in 1993 states that the centralized CHP-plants should exploit at least 1.2 million metric tons of straw and 0.2 million metric tons of wood in the year 2000. This will lead to more than twice the present exploitation of straw and an increase of wood consumption by 1520%. This is a part of a follow-up of the ENERGY 2000 plan which is necessary if the objectives am to be obtained. In 1994 over a million metric
1109
WRBC 1996 tons of straw were used for energy purposes A million mtric tons of straw corresponds to 15 PJ, which is equal to slightly less than 2% of the primary energy consumption. At present, forests cover 12% of Denmark and this area is expected to be doubled during the next ce.ntury. This means that the potential from waste in forestry and industry is quite large and still increasing. Wood chius are mainly used as fuel in district heating and central&d CHP plants. Besides the wood chips already being exploited, an additional 200,000 metric tons should be consumed in centralized CHP plants by the year 2NlO. leading to an increa~ by 15-208 of the present total consumption of wood (including wood chips, firew& waste, etc.). Firewood is used for wood-burning stoves and wood-burning boilas At present, there are approximately 300,000 - 350,008 open wood-burning fireplaces and wood-burning stoves and approximately 20,000 - 50,000 wood-burning hoiiers.
Bioaas Biogas is produced Tom manure and organic waste. At the end of 1995 there were 15 centralized biogas farm-plants in operation i Denmark and several more undergoing planning or construction. Altogether them are 150 biogas plants - most of them established in connection with sewage treatment plants. At present, only 2 PJ ate being exploited annually out of a total energy potential of 24 PJ in animal manure. The Danish Energy plan of Action indicates that this figure should be doubled before the year 2000 and 3-doubled before the year 2005. Centralized biogas plants produce biogas and fertilizer from animal manure (approx. 7090%) from a number of farms and organic waste from industry (N-30%). The plants produce 1,000 to 15,000 m3 metric tons of gas per day from 50 to 500 metric tons of feed stock. Biogas is most often used for combined heat and power (CI-IP) generation. The volume of gas production has increased since the implementation of co-digestion of manure and other organic waste with easily digestible organic matter. Gas production of 80-100 m’ per metric ton of feed stock is achieved nowadays. In 1995 the centralized biogas plants produced 0.7 PJ. All the biogas plants produced an average of about 2.0 PJ. In general, the biogas plants are co-operative companies owned by the farmers who &liver the manure. Altogether, central&d biogas plants are energy-producing plants which give general benefits: After digestion the manure is a homogenous, well defined fertilizer which can be used efficiently. This means less waste of - and pollution from nutrients. Waste from industry and households is recycled back to farmland which means savings regarding srtificial fertilizer and reduced waste deposits. Waste becomes an income instead of an expense. Biogas is substituting fossil fuels and thus reducing CO,-emissions. Biogas reduces CH4-emissions from slurry storages. An economic and environmental disadvantage is the manure transportation. The co-digestion of organic waste from industry is economically necessary for the plants, but it is risky to depend on this resource, as there might in the (near) future be a shortage of attractive industrial waste supplies. It is therefore clear that one of the most important tasks will be to make (economic) improvements in order to provide independence from industrial wastes.
1110
WREC 1996 SOLAR ENERGY There are about 18,000 solar heating systems in Denmark corresponding to approximately 170,080 m2. A solar heating system is to be understood as a system which converts the suns radiant energy to heat. In Denmark, the incident solar radiation is on average 1200 kWh per m2 on a surface facing south with a tilt of 45 degrees from horizontal. The typical output for a small solar heating system for domestic hot water will be approximately 500 kWh per m2. The majority are systems for producing domestic hot water for single family houses, multi- storey dwellings, institutions and such-like. The annually exploited quantity of energy from solar heating systems can be roughly estimated for 1995 as approximately 252 TJ (70 GWh). Additionally, building integrated passive solar systems are assumed to deliver a little less and solar energy can thus be assumed to cover all in all approx. 0.30% of the total Danish consumption of energy for heating snd domestic hot water. If the development continues as it has during recent years - namely sale of approx. 2500 systems annually -the energy production from the plants will be around 620 TJ by the year 2005. This, however, is far too low, as the goal is to establish 4000 - 6000 plants per year and it is assumed in the Plan of Action for Solar Energy that it could be possible to cover 7-8 PJ annually by the year 2005. The barriers for exploitation of solar energy are mainly economic and therefore it is part of the Plan of Action to reduce the price of the plants. To achieve this the Energy Agency has already established cooperation with the large supply utilities and efforts will be made within the area of leasing solar heating systems and installation of solar heating in houses formerly heated by electricity. In order to achieve subsidy from the Government the solar heating systems are tested and the output is evaluated at the national Solar Energy Laboratory.
REFERENCES Biopress. Dansk Bioenerzi. Danish Energy Agency (1995). Prozress retort on the economy of centralized biozas slants. Danish Energy Agency. Wind turbines. Energistyrelsen (1995). Bioeasf~llesanlrea - fra ide til virkelizhed. Energistyrelsens faglige udvalg for biomasse til energifonngl (1995). Forslaz til bioenerzi udviklinnsoroaram BUP-95. Energistyrelsens faglige udvalg for vindkraft (1995). Status og nersnektiver for vindenerzi i Udvikbnzsorozmmmet for Vedvarende Energi. Milje- og Energiministeriet, Energistymlsen (1995). Vedvarende energi - nve initiativer. Renewable Energy Information Centre (1995). Solar heatinn in Denmark - medium sized nlants. R&let for Vedvarende Energi (1995). Vedvarende enerzi i Danmark - status oz handlinesulan. Solar Energy Committee (1995). Plan of Action for Solar Energv 199597. The Centre of Biomass Technology (1992). Straw for energy production - technology, environment. economy. Torben Skott. Biozas, me, halm, etc. & Danish Wind Turbine Manufacturers Association. Energy- and Environment Data, Aalborg. Solar Energy Laboratory, Danish Technological Institute. Test Station for Wind Turbines, Ris#.
1111
RENEWABLE ENERGY IN DENMARK IBEN OSTERGAARD
Renewable Energy Information Centre, Danish Technological Institute, P.O. Box 141, DK-2630 Taastrup, Denmark.
ABSTRACT About 7-8% of the primary energy consumption was covered by renewable energy by the end of 1995. There are difficulties in reaching the overall CO+duction goals and renewable energy sources should therefore hopefully bear some of the brunt The paper deals with the status and perspectives of exploiting wind energy, biomass, and solar energy.
KEYWORDS Renewable energy in Denmark, wind energy, biomass, solar energy.
Renewable enema. In the plan of action, “ENERGY 2500”, drawn up by the Danish Miistry of Energy in 1990, the objective for 2005 is that 10% of the primary energy consumption should be covered by renewable energy. About 7-896 of the primary energy consumption was covered by renewable energy by the end of 1995, so for the renewable energy part there do not seem to be any problems. However, there are great difficulties in reaching the overall CO,-reduction goals in the plan of action: reduction of CO2-emission by at least 20%. and renewable energy sources should therefore hopefully bear some of the brunt
WIND ENERGY Denmark is a windy country and we have a tradition for exploiting the wind. At present, there are about 3,860 wind turbines in Denmark with a capacity of approximately 637 MW. About half of the wind turbine capacity which has been installed world-wide during recent years is Danish and over half of the wind turbines around the world were produced in Denmark. The wind turbines in Denmark produced about 1.2 biion kWh in 1995 and thus saved the environment from approximately 1.2 million metric tons of CO,. It is realistic to assume that
1108
WREC 1996 wind power alone can contribute about 20% of the total CQ- reduction by letting 10% of Denmark’s electricity consumption be delivered by wind turbines with a capacity of 1500 MW. This is the capacity which the Danish energy plan assumes wiIl be established in Denmark by the year 2005, cotresponding to an annual enlargement amounting to 80-100 MW. During recent years only 30-75 MW have been achieved per year. This is due to several reasons such as: difficulties regarding siting, decmase in the payment for the electricity, limited possibilities for private people to invest in wind energy. However, in 1995 a satisfactory 98 MW were achieved. The growth in the use of wind energy in Denmark is to a high degtee based on private initiative and enthusiasm. Approximately 70% of the wind turbine capacity in Denmark is owned by private inividuals, whilst the remainder is owned by the electricity utilities. Nowadays, it is most common for a large wind turbine to be owned by a community - a so-called wind turbine guild. A wind turbine with an annual production of 500,000 kWh will have about 60 households as its owners. The electricity is sold to the local electricity utility, and the overall price including CO,-duty and energy duty refund, typically DKK 0.50-0.60 per kWh is achieved. There are about 8 Danish producers of type-approved wind turbines. The Danish wind turbine manufacturers export by far the greatest part of their production, namely approximately 479 MW out of a total on 577 MW in 1995. The wind turbine trade employs about 1,600 persons directly and about 8,500 persons when subsuppliers am included. The Danish electricity utilities have mainly developed large scale wind turbines - the newest one is a 1 MW turbine put into operation in 1993. Since 1985 the utility companies have also added commercial wind turbines in two 100 MW programmes and it is the intention of the energy plan that the electricity utilities will still play an active role in the development of wind energy.
BIOMASS Biomass comprises natural resources consisting of straw, manure from farms, wood chips and wood, organic waste from households and industries. Biomass is a very significant resource and it covers 80% of the energy supply from renewable energy sources in Denmark. In 1995 biomass covered about 5% of the primary energy consumption. In Denmark it was in connection with the oil crises in the seventies that the new era for the exploitation of biomass was opened. It was the shortage of oil and increasing oil prices that led to attempts to diversify the energy supply in Denmark. It was a decentralized implementation of the use of biomass as thousands of people re-installed some kind of wood-fired oven leading to important economizing on imported oil.
Wood and straw Wood and straw make up far the largest part of biomass exploitation in Denmark. The so-called “Biomass-agreement” drawn up by the Danish government in 1993 states that the centralized CHP-plants should exploit at least 1.2 million metric tons of straw and 0.2 million metric tons of wood in the year 2000. This will lead to more than twice the present exploitation of straw and an increase of wood consumption by 1520%. This is a part of a follow-up of the ENERGY 2000 plan which is necessary if the objectives am to be obtained. In 1994 over a million metric
1109
WRBC 1996 tons of straw were used for energy purposes A million mtric tons of straw corresponds to 15 PJ, which is equal to slightly less than 2% of the primary energy consumption. At present, forests cover 12% of Denmark and this area is expected to be doubled during the next ce.ntury. This means that the potential from waste in forestry and industry is quite large and still increasing. Wood chius are mainly used as fuel in district heating and central&d CHP plants. Besides the wood chips already being exploited, an additional 200,000 metric tons should be consumed in centralized CHP plants by the year 2NlO. leading to an increa~ by 15-208 of the present total consumption of wood (including wood chips, firew& waste, etc.). Firewood is used for wood-burning stoves and wood-burning boilas At present, there are approximately 300,000 - 350,008 open wood-burning fireplaces and wood-burning stoves and approximately 20,000 - 50,000 wood-burning hoiiers.
Bioaas Biogas is produced Tom manure and organic waste. At the end of 1995 there were 15 centralized biogas farm-plants in operation i Denmark and several more undergoing planning or construction. Altogether them are 150 biogas plants - most of them established in connection with sewage treatment plants. At present, only 2 PJ ate being exploited annually out of a total energy potential of 24 PJ in animal manure. The Danish Energy plan of Action indicates that this figure should be doubled before the year 2000 and 3-doubled before the year 2005. Centralized biogas plants produce biogas and fertilizer from animal manure (approx. 7090%) from a number of farms and organic waste from industry (N-30%). The plants produce 1,000 to 15,000 m3 metric tons of gas per day from 50 to 500 metric tons of feed stock. Biogas is most often used for combined heat and power (CI-IP) generation. The volume of gas production has increased since the implementation of co-digestion of manure and other organic waste with easily digestible organic matter. Gas production of 80-100 m’ per metric ton of feed stock is achieved nowadays. In 1995 the centralized biogas plants produced 0.7 PJ. All the biogas plants produced an average of about 2.0 PJ. In general, the biogas plants are co-operative companies owned by the farmers who &liver the manure. Altogether, central&d biogas plants are energy-producing plants which give general benefits: After digestion the manure is a homogenous, well defined fertilizer which can be used efficiently. This means less waste of - and pollution from nutrients. Waste from industry and households is recycled back to farmland which means savings regarding srtificial fertilizer and reduced waste deposits. Waste becomes an income instead of an expense. Biogas is substituting fossil fuels and thus reducing CO,-emissions. Biogas reduces CH4-emissions from slurry storages. An economic and environmental disadvantage is the manure transportation. The co-digestion of organic waste from industry is economically necessary for the plants, but it is risky to depend on this resource, as there might in the (near) future be a shortage of attractive industrial waste supplies. It is therefore clear that one of the most important tasks will be to make (economic) improvements in order to provide independence from industrial wastes.
1110
WREC 1996 SOLAR ENERGY There are about 18,000 solar heating systems in Denmark corresponding to approximately 170,080 m2. A solar heating system is to be understood as a system which converts the suns radiant energy to heat. In Denmark, the incident solar radiation is on average 1200 kWh per m2 on a surface facing south with a tilt of 45 degrees from horizontal. The typical output for a small solar heating system for domestic hot water will be approximately 500 kWh per m2. The majority are systems for producing domestic hot water for single family houses, multi- storey dwellings, institutions and such-like. The annually exploited quantity of energy from solar heating systems can be roughly estimated for 1995 as approximately 252 TJ (70 GWh). Additionally, building integrated passive solar systems are assumed to deliver a little less and solar energy can thus be assumed to cover all in all approx. 0.30% of the total Danish consumption of energy for heating snd domestic hot water. If the development continues as it has during recent years - namely sale of approx. 2500 systems annually -the energy production from the plants will be around 620 TJ by the year 2005. This, however, is far too low, as the goal is to establish 4000 - 6000 plants per year and it is assumed in the Plan of Action for Solar Energy that it could be possible to cover 7-8 PJ annually by the year 2005. The barriers for exploitation of solar energy are mainly economic and therefore it is part of the Plan of Action to reduce the price of the plants. To achieve this the Energy Agency has already established cooperation with the large supply utilities and efforts will be made within the area of leasing solar heating systems and installation of solar heating in houses formerly heated by electricity. In order to achieve subsidy from the Government the solar heating systems are tested and the output is evaluated at the national Solar Energy Laboratory.
REFERENCES Biopress. Dansk Bioenerzi. Danish Energy Agency (1995). Prozress retort on the economy of centralized biozas slants. Danish Energy Agency. Wind turbines. Energistyrelsen (1995). Bioeasf~llesanlrea - fra ide til virkelizhed. Energistyrelsens faglige udvalg for biomasse til energifonngl (1995). Forslaz til bioenerzi udviklinnsoroaram BUP-95. Energistyrelsens faglige udvalg for vindkraft (1995). Status og nersnektiver for vindenerzi i Udvikbnzsorozmmmet for Vedvarende Energi. Milje- og Energiministeriet, Energistymlsen (1995). Vedvarende energi - nve initiativer. Renewable Energy Information Centre (1995). Solar heatinn in Denmark - medium sized nlants. R&let for Vedvarende Energi (1995). Vedvarende enerzi i Danmark - status oz handlinesulan. Solar Energy Committee (1995). Plan of Action for Solar Energv 199597. The Centre of Biomass Technology (1992). Straw for energy production - technology, environment. economy. Torben Skott. Biozas, me, halm, etc. & Danish Wind Turbine Manufacturers Association. Energy- and Environment Data, Aalborg. Solar Energy Laboratory, Danish Technological Institute. Test Station for Wind Turbines, Ris#.
1111