Bill Gross has plenty to celebrate this Earth Day, as seeds he planted a dozen years ago begin to bear fruit. Idealab Inc., the technology incubator he founded in 1996, is leading a whopping $130 million investment in eSolar Inc., which makes pre-fabricated solar power plants. Oak Investment Partners and Google Inc.'s philanthropic investment arm, known as Google.org, are participating in the round, announced earlier this week.

"We've started more than 100 companies in 12 years," Gross tells Tech Confidential, referring to Idealab. "A lot of our companies did not succeed, but we learned from the ones that didn't succeed."

For Gross, eSolar is proof that the incubator model he's using at Idealab works -- at least for him. "I wouldn't recommend that anyone start an incubator, because it's really, really hard, but it works for us."

The idea for eSolar was something the team at Idealab brainstormed internally, according to Gross, who serves as the startup's chairman. "We have so much visibility into solar," he says. Idealab has also spawned Energy Innovations Inc., which is developing the Sunflower, an innovative mass-produced rooftop photovoltaic tracking concentrator system. Backed by MDV-Mohr Davidow Ventures in addition to Idealab, Energy Innovations is behind the solar-powered electricity system installed at Google's headquarters.

"We have so many different efforts inside of Idealab that are using so much of the same shared knowledge," explains Gross. "We have our own machine shop and a full photovoltaic lab on the rooftop measuring things."

Collective wisdom translated into a speedy ramp-up for eSolar, says Gross. "Nobody has ever built a power plant this fast," reporting that the company began testing plants in the field just a year ago.

Prefabrication of small, modular power plants is the key. "We build them in the factory and then bring them out to the field. We're saving on installation and construction because we're using robots in a factory insetad of expensive crews," he says. "Because they're so small --  just one square mile -- you can put them right next to the power line, instead of having to put them far out in the desert, where you have to use huge distribution lines and worry about the environmental impact."

eSolar's goal is to sell the utilities solar power less expensively than power from fossil fuels, such as natural gas.

Gross says the funding will be used to accelerate the deployment of plants and to "show that we can produce them quickly and get them online very fast." He expects eSolar will deliver competitively priced power to the grid by the end of the year. -- Mary Kathleen Flynn

For more on Bill Gross, see Aug. 2007 special report on cleantech from Tech Confidential
For more on eSolar, see the company's April 21 press release, April 21 story from Wired and April 22 story from Clean Edge