American Council for and Energy-Efficient Economy (ACEEE), July 2, 2014, by Anna Chittum and Neal Elliott. (Free registration required to view full-text of report.)
http://www.aceee.org/policy-brief/combined-heat-and-power-and-clean-distributed-energy-poli

"Combined heat and power (CHP) systems generate electricity and useful thermal energy in a single, integrated system. CHP is not a technology, but a particular way to deploy existing technologies. Heat that is normally wasted in conventional power generation is recovered as useful energy, so CHP systems are more efficient and provide environmental, economic, and energy system infrastructure benefits. However, several barriers impede cost-effective CHP applications, including lack of common interconnection protocols, discriminatory standby rates, and emissions regulations that do not recognize the improved efficiency levels of CHP systems."