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Having just reported a golden quarter, Google (Nasdaq: GOOG) can now go about stunning skeptics in other arenas. Take Big Goo's green energy initiative, for example.

Back in November, Google announced that it's getting into the renewable energy game. The "Renewable Energy Cheaper Than Coal," or RE<C program, was received coolly by my colleagues. I, however, saw an element to the endeavor that may give Google's gambit an edge. Aside from having a ridiculous bankroll, Google knows a thing or two about scalable solutions.

That's exactly what the company appears to have found with its investment in eSolar. The solar thermal start-up, which just raised an additional $130 million from Google.org, along with other investors, uses mirrors to heat a central water boiler and, in turn, power a steam turbine. Nothing new there. However, eSolar's heliostat mirrors are cheap, small (helping to reduce a project's footprint), and have software-driven sun-tracking capabilities. You knew computing had to enter the picture somewhere.

In addition to these attractive features, eSolar's plants sport a modular design -- think cookie-cutter suburban homes -- that should make them radically cheaper and quicker to build than desert behemoths like the billion-dollar Solana plant in Arizona.

Modularity aside, the problem with large, remote solar plants is that they take longer to permit, and they don't neatly tuck in to the electric grid. For both of those reasons, eSolar is going small. According to eSolar's chairman, sub-50 megawatt plants don't even need to be licensed by California's state energy regulator.

SunPower (Nasdaq: SPWR) and First Solar (NYSE: FSLR) now have an interesting challenger in the race to grid parity. I'd tell King Coal to watch his back as well, if it weren't for the export bonanza fueling Peabody Energy (NYSE: BTU) and Arch Coal (NYSE: ACI) yesterday.

Related Foolishness:

  • I regrettably left solar thermal out of my overview of solar innovation.
  • Fortunately, fellow Fool Tim Beyers has covered rival Ausra, a Baby Breaker.

Fool contributor Toby Shute doesn't have a position in any company mentioned. The Motley Fool has a disclosure policy.