Steam Power Plant, Fossil-Fuel-Fired

an electric power plant that produces electricity by converting the thermal energy released during the combustion of an organic fuel. Fossil-fuel-fired steam power plants first appeared in the late 19th century—in 1882 in New York, in 1883 in St. Petersburg, and in 1884 in Berlin—and became the preferred form of electric power generation; in the mid-1970’s they are still the principal type of electric power plant. In 1975 they accounted for more than 80 percent of the electricity produced in the USSR and the USA; in 1973 they produced about 76 percent of the world’s electricity.

Thermal steam-turbine power plants are the most common type; they use the thermal energy in a steam generator to obtain high-pressure steam. The steam drives the rotor of a steam turbine connected to the rotor of an electric generator, usually a synchronous generator. In 1975 thermal steam-turbine power plants accounted for approximately 99 percent of the electricity produced by all fossil-fuel-fired steam power plants. The principal fuel used at such plants is coal, but mazut, natural gas, lignite, peat, and shales are also used. Such power plants have efficiencies up to 40 percent and capacities up to 3 gigawatts. Thermal steam-turbine power plants with total design capacities up to 5–6 gigawatts are being built in the USSR.

Thermal steam-turbine power plants that use condensation turbines to drive the electric generators and that do not use the heat of the exhaust steam to supply thermal energy to outside users are called condensation electric power plants (the official term in the USSR is “state regional power plant”). Approximately two-thirds of the electric energy produced at fossil-fuel-fired steam power plants comes from state regional power plants. Thermal steam-turbine power plants that are equipped with turbines that deliver the heat of the exhaust steam to industrial or municipal and domestic consumers are called district heat and power plants. They account for approximately one-third of the electricity produced by fossil-fuel-fired steam power plants.

Plants in which the generators are driven by gas turbines are called gas-turbine power plants. In such plants, gas or liquid fuel is burned in the combustion chamber, and the combustion products (at temperatures of 750°–900°C) enter a gas turbine, which turns the electric generator. The efficiency of such plants is usually 26–28 percent, and their capacities range up to several hundred megawatts. Gas-turbine power plants are usually used to cover peak electrical loads.

Plants with a steam-gas turbine installation consisting of a steam-turbine generating unit and a gas-turbine generating unit are called steam-gas power plants. Their efficiency may reach 42–43 percent. Gas-turbine and steam-gas power plants can also supply heat to outside consumers, that is, operate as district heat and power plants.

Atomic power plants, power plants with magnetohydrodynamic generators, and geothermal power plants are sometimes classified as steam power plants.