A fossil-fuel power station is a power station that burns fossil fuels such as coal, natural gas or petroleum (oil) to produce electricity. Central station fossil-fuel power plants are designed on a large scale for continuous operation. In many countries, such plants provide most of the electrical energy used.
Fossil fuel power stations (except for MHD generators) have some kind of rotating machinery to convert the heat energy of combustion into mechanical energy, which then operate an electrical generator. The prime mover may be a steam turbine, a gas turbine or, in small isolated plants, a reciprocating internal combustion engine. All plants use the drop between the high pressure and ...view middle of the document...
A recent study indicates that sulfur emissions from fossil fueled power stations in China have caused a 10-year lull in global warming (1998-2008)
1 Basic concepts
1.1 Heat into mechanical energy
2 Fuel transport and delivery
3 Fuel processing
5 Gas turbine plants
6 Reciprocating engines
7 Environmental impacts
7.1 Carbon dioxide
7.2 Particulate matter
7.3 Radioactive trace elements
7.4 Water and air contamination by coal ash
7.4.1 Range of mercury contamination in fish
8 Greening of fossil fuel power plants
8.1 Low NOx Burners
8.2 Clean coal
9 Combined heat and power
10 Alternatives to fossil fuel power plants
10.1 Relative cost by generation source
11 See also
14 External links
In a fossil fuel power plant the chemical energy stored in fossil fuels such as coal, fuel oil, natural gas or oil shale and oxygen of the air is converted successively into thermal energy, mechanical energy and, finally, electrical energy for continuous use and distribution across a wide geographic area. Each fossil fuel power plant is a highly complex, custom-designed system. Construction costs, as of 2004, run to US$1,300 per kilowatt, or $650 million for a 500 MWe unit. Multiple generating units may be built at a single site for more efficient use of land, natural resources and labour. Most thermal power stations in the world use fossil fuel, outnumbering nuclear, geothermal, biomass, or solar thermal plants.
Heat into mechanical energy
The second law of thermodynamics states that any closed-loop cycle can only convert a fraction of the heat produced during combustion into mechanical work. The rest of the heat, called waste heat, must be released into a cooler environment during the return portion of the cycle. The fraction of heat released into a cooler medium must be equal or larger than the ratio of absolute temperatures of the cooling system (environment) and the heat source (combustion furnace). Raising the furnace temperature improves the efficiency but complicates the design, primarily by the selection of alloys used for construction, making the furnace more expensive. The waste heat cannot be converted into mechanical energy without an even cooler cooling system. However, it may be used in cogeneration plants to heat buildings, produce hot water, or to heat materials on an industrial scale, such as in some oil refineries, plants, and chemical synthesis plants.
Typical thermal efficiency for electrical generators in the industry is around 33% for coal and oil-fired plants, and up to 50% for combined-cycle gas-fired plants. Plants designed to achieve peak efficiency while operating at capacity will be less efficient when operating off-design (i.e. temperatures too low.)
The worlds most efficient Coal-fired Power Station is Vattenfall's 400MWe, Unit 3 at Nordjylland Power Station.
The Carnot cycle is the...