One-Twelfth of Global Electricity Comes from Combined Heat and Power Systems

Amanda Chiu | Oct 29, 2008

Just over 8 percent of world electricity generating capacity uses cogeneration, also known as combined heat and power (CHP)—an integrated energy system that produces both electricity and heat.1 Cogeneration plants have a total global installed electricity capacity of some 325,000 megawatts (MW).2

Combined heat and power captures waste heat as electricity is produced and recycles it to provide another energy service, unlike conventional systems in which heat is simply exhausted into the environment and additional fuel must be used to provide the same amount of heat to industry or buildings. Another form of cogeneration captures waste energy from industrial processes and recycles it into useful electricity and thermal power.

The advantage of combined heat and power over separate generation is efficiency. An average coal-fueled power plant converts 33 percent of its fuel to usable energy services.3 The most efficient, natural gas–fueled plant has a conversion efficiency of 60–64 percent.4 In contrast, CHP systems have efficiency ratings of 75–90 percent, with lower losses from transmission and distribution of electricity due to the close proximity of the generator and consumer and with fewer condensation losses in boilers.5

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