CPower has raised $10.7 million in a second round of funding to help it expand its demand response services.

New investor the Mayfield Fund led the round, and was joined by previous investors including Bessemer Venture Partners, Expansion Capital Partners, Schneider Electric Ventures, New York City Investment Fund and Consensus Business Group. New York-based CPower previously raised $17 million in September 2007.

CPower, which was founded as ConsumerPowerline in 2001 and changed its name in 2008, has gathered a portfolio of about 2,200 megawatts under management, most recently landing a 200-megawatt demand response contract with Maryland utilities Allegheny Power, Delmarva Power and Light Company and Potomac Electric Power Company (PEPCO).

That puts it in a roster of demand response competitors including EnerNoc (NSDQ:ENOC), Comverge (NSDQ:COMV), EnergyConnect and Constellation NewEnergy in terms of power under management. These companies help customers take part in utility or grid operator programs that pay for the promise to cut energy use when they're facing peak loads.

That makes demand response aggregators providers of "negawatts" that help utilities avoid the need to build coal- or gas-fired "peaker" plants (see EnerNoc Harvests Power in Maryland). Most demand response companies work with commercial and industrial clients, though a few like Comverge also participate in residential demand response programs (see Demand Response: The Home vs. C&I Debate).