If connected to a smart grid, the OPower software can provide detailed information on energy usage and then generate recommendations on how to reduce specific items, such as air conditioning load.

OPower, a company that offers home energy efficiency recommendations to consumers through utilities, has brought in $50 million in venture capital.

The Arlington, Va.-based company said yesterday that the round was led by Kleiner, Perkins, Caufield & Byers and Accel Partners, with existing investor New Enterprise Associates also participating. Since its founding in 2007, OPower has raised $65.5 million.

With the money, OPower plans to hire more people and build out its Web-based software system to introduce more features to consumers and utilities next year, said CEO Dan Yates.

There have been dozens of companies trying to build a business around giving consumers tools to save energy, with many designing home energy monitors. OPower has made a name for itself by first offering paper reports that tell consumers how their energy use compares with households like theirs. People can also go to a utility-hosted Web site to view their energy data and recommendations for efficiency.

Next year, the company plans to improve its software in an effort to increase consumer energy savings, Yates said. Right now, the average energy reduction is on the order of 2 or 3 percent, which when aggregated over many homes is significant to utilities that have an incentive to improve customers' efficiency.

OPower also intends to build out its software service to give utilities more tools for communicating with consumers as utilities introduce smart meters and demand-response programs, Yates said. The company is now working with 45 utilities in the U.S.