02 March 2001
Cogeneration in Europe leads balanced electricity policy
California dreams on amid rolling blackouts and buck passing.
Ten years ago, Britain deregulated its electricity industry. The rest of Europe followed shortly after, in line with the European Union's (EU's) policy of a single market. California tried to follow the British model and failed.
Today, most of Europe trades power through national exchanges and, increasingly, through regional and transnational exchanges. Such trading is intensely competitive and operates electronically on a minute-by-minute basis, as major consumers attempt to minimize their bills.
This rapid, intensive trading has spawned a new controls and instrumentation market that barely existed in the 1980s. Equally important, consumers are also becoming producers.
Many European plants have generated a portion of their own electricity consumption since the end of World War II and the early 1950s because much of the infrastructure was in ruins. Such cogeneration and combined heat and power (CHP) plants have experienced rapid growth since deregulation drastically altered their economics.
There are 14 cogeneration CHP plants within three miles of the center of Tampere, Finland, whose population is only 100,000. Five years ago, there were just six.
Consider two companies that typify the European situation: Finland's Wartsilä—a manufacturer of cogeneration systems—and Britain's International —a subsidiary of National Power and a self-described developer.
Wartsilä typifies the rapid growth that is occurring in this area: Net sales increased 52% between third-quarter 1999 and third-quarter 2000. The company's installations cover a very wide range. At the low end of the scale lie systems such as those at Torup Gronne Gartnerier Aps, a Danish farm that produces 30,000 cucumbers a day in heated greenhouses.
Installing a CHP system fueled by natural gas and fitted with a thermal reservoir to conserve heat for nighttime use proved economic because electricity sold to the grid at high daytime tariffs.
This is in line with a government policy of encouraging the purchase of electricity from diverse sources. Built in 1997, the installation provides 2.8 megawatts (MW) of electric power and 2.9 MW of heat and has a total efficiency of more than 90%.
At the opposite end of the scale is an installation at a Peugeot automobile factory in eastern France. Unlike the Danish government, the French government did not adopt a cogeneration policy until 1995, and even now EDF, the French national utility, will buy power only from plants whose efficiency exceeds 65%.
At the Peugeot plant, a 20-MW system produces 10 megawatt hours of hot water and 12 tons of steam per hour. On hot water alone, Peugeot figured, the yearly savings over the former oil-fired system are equivalent to the value of more than 100 cars produced.
The plant operates annually from 1 November to 31 March continuously at full load. The selling price of electricity is presently not attractive enough to operate the plant during the warmer months of the year.
One installation that typifies National Power's approach is at Conoco's refinery at Killingholme, U.K. Here, a system for the supply of 24 MW of electricity and more than 90 MW of steam was commissioned in 1997.
The setup features four independent gas turbines with backup systems to ensure continuous running even when primary gas supply is unavailable. Higher up the scale of operations comes the Winnington CHP plant in Northwich, Cheshire, which on completion will be the largest such facility in the U.K.
The system will supply a total of 400 MW of steam and 130 MW of electric power to two Brunner Mond (U.K.) Ltd. soda ash works. When available and when tariffs make it economical to do so, the design sells electricity back to the grid. Turbines that are used to drop steam pressure to on-site levels generate additional electricity.
Cogeneration is alive and well and living in Europe. In the new economic climate, it is proving remarkably profitable and, large or small, is clearly here to stay. Hospitals, paper mills, engineering plants, schools, universities, and business parks are all joining the game, aided by installations that are fully automatic—including the trading systems—and that provide exceptional levels of availability. IT
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- In retrospect, it was California dreaming