In the Opinion of COGEN Europe, an Association That Promotes Cogeneration, the Development of combined heat and power (CHP)/cogeneration in Europe is at a critical stage. Privatization and deregulation of the electric power industry, plus environmental concerns, are not only challenging the cogeneration industry, they are also presenting opportunities, says COGEN Europe.
Although long term, the market for the cogeneration industry looks promising, the short-term prospects do not look as good. According to COGEN Europe, the cogeneration industry in Europe will face many challenges over the next three years.
Globally, cogeneration accounts for approximately 7 percent of the electric power produced. Some European countries, such as the Netherlands, use cogeneration to supply more than 40 percent of their electricity. The European Union's goal is to double the share of electricity from cogeneration by 2010, to about 18 percent.
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Typically, cogeneration plants achieve a 15-35 percent reduction in primary energy usage compared to tradition power plants that only produce electricity. Because cogeneration is more efficient than conventional power, less pollution is generated per kilowatt of energy produced.
A Liberalized Market
As European countries have deregulated and liberalized their electric power industries, the market for independently owned cogenerated electric power has increased. Although there has been an increase in electricity from cogeneration, the price for the electricity has decreased. In Finland, for instance, the low prices paid for cogenerated electricity makes many plants unprofitable. This is further compounded when the price of the thermal energy is also low.
 GTX 100 gas turbine will be installed at the Stoke-on-Trent plant in England. Photograph courtesy of Alstom Energy. |
Although the profitability of many cogeneration plants in Finland is unsatisfactory and the majority of the suitable sites have been utilized, developers are still investing in cogeneration projects. However, most of this investment is in replacing or upgrading older plants. Few, if any, are greenfield projects.
Cogeneration plants are very site specific and it is not always possible to maximize the ratio of thermal energy to electric energy. The type of fuel used also makes a difference. In general, when a solid fuel is burned, a cogeneration plant produces 30 percent electric energy and 60 percent thermal energy. A natural gas-fired cogeneration plant, on the other hand, produces 45 percent electric energy and 45 percent thermal energy. These figures can vary according to the size of the plant and the pressure or temperature of the thermal energy supplied.
Sizing of cogeneration plants in Finland is generally determined by the thermal heat demand. When there is a heat demand, the generation of electricity becomes profitable. Thermal energy from cogeneration in Finland is typically used for district heating.
Finnish Experience
Natural gas is the main fuel used by cogeneration plants in southern and southeastern Finland. In the rest of Finland cogeneration plants burn solid fuels, including coal and peat.
Fortum Corp., an international energy company, was formed by two Finnish companies: IVO Group and Neste Group. The combined company is actively involved in the energy sectors of the Nordic countries and the Baltic Rim. According to Fortum, its objective is to be one of the leading energy enterprises in Northern Europe.
A Finnish wood processing company, Säteri Oy, has an on-site cogeneration and a water supply plant owned and operated by Fortum. The cogeneration and water plants supply the wood processing facility with electricity, thermal energy and water.
In addition to supplying the plant with electricity, thermal energy and water, Fortum also supplies the Säteri Oy facility with compressed air, and operation and maintenance services for the plant's waste incinerator and the cogeneration and water supply plants.
Like many cogeneration plants, the Fortum facility uses a variety of fuels, including natural gas, peat, biomass and wood waste. Oil and coal are also used, but are not the fuels of choice.
Conversion
Between 1960 through 1972, three coal-fired condensing power units were constructed in Naantai in southwestern Finland. In the 1980s, two of the units were converted to district heating. Today, the plant supplies district heat to four towns, but the towns are responsible for the retail distribution and sale of the district heat.
Process steam from the plant is supplied to seven industrial sites including Fortum's Naantai refinery, Cultor Oy's food processing plant, Raisio Oy's animal feed plant, and Mobil Oy's lubricating oil manufacturing facility. The refinery supplies refinery gas and oil to fuel the district heating plant.
Heating plants and electric power plants, previously owned by industry and some of the towns, were shut down once the remodeled district heating plants went into service. Besides the economic saving to the towns, emissions from energy production have also been reduced.
Dutch Leader
In the Netherlands, cogeneration in many instances is a joint venture between industry and electric utilities. EPON is a major supplier of electric power and thermal energy in the Netherlands. Not only does the company own, operate and maintain cogeneration plants, it also designs them.
EPON, with a total generating capacity of 5,000 MWe, supplies approximately 23 percent of the electricity produced in the Netherlands. Most of the plants are gas-fired units. However, they have one 602 MW coal-fired plant located in Nijmegen.
The Dutch city of Almere, the country's fastest growing city, receives 55 percent of its district heating needs from the EPON Almere cogeneration plant. The plant, constructed in 1981, was originally a pure thermal heating power plant. Today, the plant has capacities of 311 MWt and 118 MWe.
Thermal energy, in the form of hot water, is used for district heating. However, the electric power generated by the plant is supplied to the Dutch electric grid system.
The Almere plant's primary function is to supply thermal energy for district heating. Because of this, the plant operates to supply the district heating requirements of the city rather than the electric needs of the grid. Only in exceptional situations is the plant operated to supply the grid. When this occurs, any thermal energy not required for district heating is wasted.
A Century of Power
One of the largest cogeneration plants in Scandinavia is the Värtan cogeneration plant in Stockholm, Sweden. Until the early 1960s, the plant only produced electric power, with coal as the major fuel. With the development of the district heating system in central Stockholm, plus the advent of less expensive fuel oil, the plant was converted to oil.
Because of increasing costs of fuel oil in the 1980s and the development of clean coal technologies, the plant was converted back to coal. According to Birka Energi AB, Värtan was the world's first commercial scale coal-fired pressurized fluidized bed combined-cycle (PFBC) cogeneration plant. In 1995, Värtan became a trigeneration plant when it started to produce cooling. Currently, the plant has a capacity of 1760 MW heat, 435 MW electricity and 80 MW of cooling.
Värtant has three main blocks:
- PFBC cogeneration unit (plant 6),
- Heat pumps, and
- Cogeneration unit (plant 1).
The above table shows the installed capacity and fuels used by the three blocks.
Plant 6 consists of two PFBC modules, two 15 MW gas turbines and one steam turbine. The heat pump block, with 10 heat pumps, generates more than 50 percent of Värtan's total heat production. Since the heat pumps produce three units of heat energy for every unit of electricity used, they are very efficient. According to Birka Energi AB, because the price of electricity is low, the heat pumps are the natural choice for baseload operation at Värtan.
In addition to using electricity, the heat pumps use low-grade solar energy stored in seawater. Depending upon the outside ambient temperature, the heat pumps are able to supply the heat energy directly for district heating. However, when the temperature of the seawater is below 5 C, the temperature has to be increased.
The oil-fired cogeneration unit, constructed in 1976, has a steam turbine and a once-through Benson boiler with single reheat. When operated as a cogeneration unit it has a capacity of 210 MWe and 330 MWt, and when operated in full condensing mode, it has a capacity of 250 MWe.
Oil-fired boilers and electric boilers, in plant 1, are operated during peak load requirements. The electric boilers were installed to take advantage of low-cost electricity when available. A vintage 1960s gas turbine is used to supply up to 250 MW of electricity as needed. However, the Swedish National Power Grid has a contract for the use of the gas turbine to support frequency control in the new deregulated power market.
Future developments at the Värtan plant include:
- Introducing solid bio-fuels for co-combustion with coal in plant 6.
- Replacing the fossil fuel oil with liquid bio-fuels.
- Investigating the use of natural gas as a substitute fuel for the fuel oil used by the cogeneration unit in plant 1.
- Converting the heat pumps from HCFC22 refrigerant to a more environmentally friendly refrigerant.
- Reducing leaks from the heat pumps to 0.01 percent.
According to Birka Energi AB, as the European electric power market deregulates and the environmental fees and taxes harmonize, natural gas and/or bio-fuel cogeneration will play an important role in the production of electricity.
Cogeneration Status in Europe
Austria - Because Austrian electric utilities have been involved in cogeneration, Austria produces a large percentage of its electric power from this technology. Austria is in the process of liberalizing its power industry.
Belgium - Although cogeneration development in Belgium has been meager, this is starting to change. Liberalization of the Belgium power industry is expected to reduce the barriers for cogeneration development. Additionally, Electrabel and SPE, the two main electric utilities in Belgium, are showing an interest in developing cogeneration projects in partnership with their customers.
Czech Republic - The majority of cogeneration in the Czech Republic is used for district heating. However, because many of the plants are inefficient and have little or no emission controls, there is a need for replacing and/or upgrading the plants. In the future, natural gas is expected to be used more widely.
Denmark -Denmark is reported to be the most advanced country in the use of cogeneration. As in other Scandinavian countries, the cogeneration plants in Denmark are generally used for district heating. In Denmark, government tax incentives and subsidies have helped the development of cogeneration. Cogeneration is being promoted by the Danish government as a tool for environmental protection. Although the government will follow the EU Electricity Directives, it does not welcome liberalization of the electric industry because of environmental concerns.
Finland - Similar to Denmark and the Netherlands, cogeneration supplies a large percentage of Finland's electricity. This has not been the result of government incentives but of economic advantages of the technology in colder climates. Cogeneration will continue to be developed although at a slower pace.
Hungary - Cogeneration is extensively used for district heating in Hungary. The potential market for cogeneration is good due to the need for new capacity and opportunities for upgrades at existing plants. The prospects for constructing large cogeneration plants are better than those for small- or medium-sized units.
Germany - Cogeneration in Germany is well developed. Nevertheless, due to some remaining barriers, the full potential of cogeneration is a long way from being realized. As the country liberalizes, the cost of electricity will likely be lower. If this happens, it could reduce the need for cogeneration. Decentralized gas-fired cogeneration has the biggest market potential.
Italy - Until recently, the outlook for cogeneration in Italy was good. However, new regulations have reduced the potential market for the technology.
The Netherlands -Because of favorable government regulations, environmental concerns and the availability of natural gas, the development of cogeneration as been very successful in The Netherlands. By the end of 2000, the government plans to have 8000 MWe, 40 percent of the country's total capacity, produced by cogeneration.
Poland -Similar to other eastern European countries, the use of cogeneration for district heating is substantial. With a need to add new capacity to replace or upgrade existing facilities, the prospects for cogeneration are good. Coal will remain the dominant fuel for the near future.
Sweden - When compared to other northern European countries, Sweden's use of cogeneration is reasonably small. However, this could change as the country phases out its nuclear power plants. When this happens, alternative forms of energy will have to be found. This, plus Sweden's concern for the environment, should work in cogeneration's favor. The government supports cogeneration using non-fossil fuels.
Cogen Projects
Alstom Power has received an order for the turnkey construction of a 53 MW cogeneration plant for PowerGen CHP in the United Kingdom. The plant will be constructed for Michelin Tire, in Stoke-on-Trent, in the English midlands. Under the contract, Alstom Power is responsible for the design, supply, construction and startup of the plant.
According to Alstom Power, the plant will take 21 months to complete and when completed will supply electric power and steam to the Michelin Tire plant. Any surplus power will be sold to the national grid.
The plant will be powered by an Alstom Power GTX100 gas turbine. When operated on natural gas, the gas turbine's Dry Low NOx emission (DLE) system will reduce the emissions of NOx and CO to less than 15 ppmv.
Fortum Engineering Oy, Helsinki, Finland, is developing an 18 MW cogeneration plant in Southern Germany. Wacker-Chemie Chemical Works in Burghausen will use electricity and process steam from the cogeneration plant.
Under the contract, GE Power Systems will supply an MS9001E gas turbine complete with two years of spare parts. The turbine, being manufactured at GE Power Systems' Belfort, France facility, is scheduled to be shipped to the plant by July 2000. Commercial operation of the cogeneration is planned for the second quarter of 2001.
Another cogeneration plant is being constructed for one of the most prestigious hotels in Paris, the Concorde Lafayette. The plant will use Caterpillar's G3516B cogeneration system. This self-contained system includes the engine, generator, heat recovery system and interconnections.
According to Caterpillar, the four-valve design of the engine allows for the complete scavenging of the exhaust gases of the engine. Consequently, lower NOx and CO2 emissions are possible. In operation, the cogeneration plant will supply all of the electricity and heat for the hotel and a conference center.