GoingGreen, part of The AlwaysOn Network, has published its list of the top 100 private companies of 2009. In addition to an overall winner, the GoingGreen 100 lists the best emerging greentech companies in several categories including Clean Energy, Energy Management, Green Automobiles and Transportation, Green Materials, Green Buildings & Green Nano/Micro-Tech, and Resource Recovery & Waste Management.

BrightSource Energy, an Oakland, California-based solar energy firm, was named as the GoingGreen 100 Overall Winner. BrightSource Energy was recently featured in a New York Times article that looked at a problem that some clean energy startups are experiencing, greenmailing.

The winner in the Green Materials, Green Buildings & Green Nano/Micro-Tech category is Calera. Calera’s tagline is “Green Cement for a Blue Planet.” The company, located in Los Gatos, California, can make cement from greenhouse gas emissions.

“The Calera process essentially mimics marine cement, which is produced by coral when making their shells and reefs, taking the calcium and magnesium in seawater and using it to form carbonates at normal temperatures and pressures. "We are turning CO2 into carbonic acid and then making carbonate," Constantz says. "All we need is water and pollution." Source: Scientific American (PDF)

Other green building companies that made the GoingGreen 100 list include Integrity Block, NanoSteel, Nanostellar, Novomer, Serious Materials, Soladigm, and Tobias Stucco.

For a full list of GoingGreen’s Top 100 Private Companies of 2009, visit the AlwaysOn website.

Photo by Marco Bellucci

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