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The efficiency of a conventional steam–electric power plant, defined as energy produced by the plant divided by the heating value of the fuel consumed by it, is typically 33 to 48%, limited as all heat engines are by the laws of thermodynamics (See: Carnot cycle). The rest of the energy must leave the plant in the form of heat.
A direct-drive 5 MW steam turbine. Electrical power stations use large steam turbines driving electric generators to produce most (about 80%) of the world's electricity. The advent of large steam turbines made central-station electricity generation practical, since reciprocating steam engines of large rating became very bulky, and operated at ...
A boiler or steam generator is a device used to create steam by applying heat energy to water. Although the definitions are somewhat flexible, it can be said that older steam generators were commonly termed boilers and worked at low to medium pressure (7–2,000 kPa or 1–290 psi ) but, at pressures above this, it is more usual to speak of a ...
A magnetohydrodynamic generator directly extracts electric power from moving hot gases through a magnetic field, without the use of rotating electromagnetic machinery. MHD generators were originally developed because the output of a plasma MHD generator is a flame, well able to heat the boilers of a steam power plant .
Emergency (standby) power systems may use reciprocating internal combustion engines operated by fuel oil or natural gas. Standby generators may serve as emergency power for a factory or data center, or may also be operated in parallel with the local utility system to reduce peak power demand charge from the utility.
Many engine–generators use a reciprocating engine, with fuels mentioned above. This can be a steam engine, such as most coal-powered fossil-fuel power plants use. Some engine–generators use a turbine as the engine, such as the industrial gas turbines used in peaking power plants and the microturbines used in some hybrid electric buses.
Nuclear power plants [9] use the heat generated in a nuclear reactor's core (by the fission process) to create steam which then operates a steam turbine and generator. About 20 percent of electric generation in the US is produced by nuclear power plants. Geothermal power plants use steam extracted from hot underground rocks. These rocks are ...
The main use for steam turbines is in electricity generation (in the 1990s about 90% of the world's electric production was by use of steam turbines) [5] however the recent widespread application of large gas turbine units and typical combined cycle power plants has resulted in reduction of this percentage to the 80% regime for steam turbines ...