DEVELOPMENTS IN FOSSIL-FUEL ELECTRICITY-GENERATION

A major part of the world's electricity is generated by the combustion of fossil fuels, and there is a significant environmental impact due to the production of fossil fuels and their combustion. Coal is responsible for 63% of the electricity generated from fossil fuels; natural gas accounts for about 20% and fuel oils for 17%. Because of developments in supply and improvements in generating efficiencies there is apparently a considerable shift towards a greater use of natural gas, and by the year 2000 it could provide 25% of the world electricity output. At the same time the amount of fuel oil burned will have decreased. The means to minimize the environmental impact of the use of fossil fuels, particularly coal, in electricity production are considered, together with the methods of emission control. Cleaner coal technologies, which include fluidized bed combustion and an integrated gasification combined cycle (IGCC), can reduce the emissions of NO(x), SO2 and CO2. Natural gas is sulphur-free and the technology of combined cycle gas turbines (CCGT) can achieve very low NO(x) levels. The use of natural gas and IGCC is therefore expected to rise considerably over the next few years because of important new developments in gas turbine technology.