Photo courtesy OZinOH via Flickr California’s ambitious goal of obtaining a third of its electricity from renewable sources by 2020 has spawned a green energy boom with thousands of megawatts of solar, wind, and biomass power plants planned for … the middle of nowhere.

And therein lies the elephant in the green room: transmission. Connecting solar farms and geothermal plants in the Mojave Desert and wind farms in the Tehachapis to coastal metropolises means building a massive new transmission system. The cost for 13 major new power lines would top $15.7 billion, according to a report released in August by the state’s Renewable Energy Transmission Initiative.

Photo: SolarReserveAt Rocketdyne’s San Fernando Valley headquarters outside Los Angeles there’s a whiff of the right stuff—of crew-cut guys in short-sleeve white shirts and skinny black ties—in a vast room that holds the massive rocket engines that propelled John Glenn and the Apollo 11 crew into space.

In one corner of this corporate space museum stands something different, though. It’s a scale model of a solar power tower, technology Rocketdyne developed a couple of decades ago as a spinoff of its work for NASA.

Here’s how it works: An array of mirrors called heliostats focuses sunlight on a receiver filled with molten salt; the stored heat can produce steam to run a solar power plant 24/7—the elusive Holy Grail of solar energy. The technology, cast off as a non-commercial curiosity in the age of $18-a-barrel oil, is now being revived and could make Rocketdyne and its parent company, United Technologies, a big player in green tech.

A Santa Monica startup called SolarReserve—founded by, yes, rocket scientists from Rocketdyne—has licensed the solar power tower technology, turning the Silicon Valley model on its head: Take a proven yet obscure technology developed years ago by an old-line tech company and marry it to the entrepreneurial culture of a startup.