15 home energy tech start-ups you should watch

There are a dizzying array of cleantech companies tackling myriad challenges of home energy management, but 15 of them just got a pretty good thumbs-up from giant technology company GE and a few of its close venture capital partners.

There are actually two groups of companies that were recognized today. The first set, 10 in all, have snagged $63 million in venture capital from GE and several venture capital partners that back the company's GE Ecoimagination Challenge series. (Over the course of the year, GE and its VC partners have given out $134 million through the different contests.) This particular contest was all about "Powering the Home," and there were apparently nearly 5,000 submissions. Here are the 10 companies that wound up claiming venture capital (listed in alphabetical order):

• Ember: This Boston-based technology develops low-powered, ZigBee-compliant chips that will find a home in smart meters and other sensor technologies that relate to the smart grid.
• GMZ Energy: Based in Waltham, Mass., the company is working on ThermoVoltaics, a technology for transforming waste heat into electricity.
• Hara: One of several winners that I know, actually. This is a San Mateo, Calif.-based developer of software for carbon and energy management.
• Nuventix: Everyone loves LEDs. This company from Austin, Texas, is working on technology to help keep them cool in lighting applications.
• On-Ramp Wireless: A San Diego company working on low-powered wireless monitoring and communications technologies.
• Project Frog: A smart building systems technology company from San Francisco.
• SunRun: One of the better known residential solar installation and financing companies, based in San Francisco.
• Viridity Energy: From Conshohocken, Pa., Viridity is working on ways that you can balance your energy consumption. Helping make better use of renewable energy technologies.
• VPhase: The company, which hails from Manchester, United Kingdom, has developed what it calls a voltage optimization device.
• WiTricity: A Watertown, Mass., firm that is working on the concept of "electricity over distance." One of the companies mentioned in my Cutting the power (cord) blog entry from last month.

There were also five companies that received a so-called "Innovation Award." Each of them will get $100,000 to help advance their technology. Those companies were:

• E.quinox: A non-profit organization from London, E.quinox is building standalone, solar photovoltaic systems that it hopes to deploy as electricity and clean water "kiosks" in developing countries.
• PlotWatt: From Durham, N.C., PlotWatt has developed smart meter data analysis software that delivers money-saving recommendations for cutting power consumption.
• Pythagoras Solar: One of the companies experimenting with in-building solar technologies, Pythagoras Solar specifically develops solar windows. The company is based in San Mateo, Calif., and I wrote about them in more detail a year ago.
• Suntulit: Based in Fremont, Calif., the company is working on smarter air-conditioning technology that adjusts depending on room temperature and occupancy data. (Note, I'm not providing a Web site, because the company doesn't seem to have a formal one yet, although it does have a Twitter account.)
• Xergy: From Georgetown, De., Xergy is working on "green" compressor technology to help refrigerators and air-conditioning systems run more efficiently.