http://www.worldofcogeneration.com/cogeneration_chp/3005-Cogenerati...

"The 80% efficiency seen in combined heat and power plants, known as cogeneration plants, is ideally suited for large institutions--universities, hospitals, airports--that have extensive electricity and thermal energy demand in a concentrated area. Rather than letting the heat escape, a cogeneration plant uses the excess energy to power a heating and cooling system."

Based on information that I'm reading, CHP is less expensive than nuclear to build, cleaner than coal fired power plants, because they utilize cleaner burning fuels such as natural gas, and more efficient as they use the steam from producing electricity to produce heat and air conditioning.  

The EPA has established the Combined Heat & Power Partnership to promote & develop these technologies.

http://www.epa.gov/chp/

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