The energy system at KPMG's suburban data center-winner of a U.S. government Energy Star award this month-is an example of combined heat and power (CHP), also known as cogeneration.

(Related: "Tapping into the Electric Power of Heat")

CHP is a "proven, reliable and cost-effective" set of technologies that could be much more widely deployed worldwide to save energy and cut carbon emissions, the International Energy Agency says.  But the IEA has identified numerous barriers that prevent CHP from taking off, from outdated electricity regulations to financing difficulties. (Lenders often want to see a shorter payback period for such investments.) The IEA concluded that strong government policy on energy and climate change may be necessary for CHP to reach its