DOE funding energy storage research for solar thermal power  

Grist has an article on some DOE research funding for energy storage for solar thermal power - A hot technology: Feds push solar solution to coal addiction.

The Obama administration last week gave a $62 million boost to efforts to make solar power truly competitive with coal.

"The projects announced today will seek to improve component and system designs to extend operation [of concentrated solar power projects] to an average of about 18 hours per day, a level of production that would make it possible for these plants to displace traditional coal-burning power plants," the Department of Energy said in a statement announcing cash grants that are being doled out over the next five years.

The recipients are companies developing technology to store energy generated by solar thermal plants so that it can be used at night or when the sun doesn't shine. In the utility biz, that's called baseload power. (Solar thermal plants typically use vast arrays of mirrors to focus the sun on a liquid-filled boiler to create steam that drives an electricity-generating turbine.)

It's hardly a huge amount of cash. But it's going to a mix of startups and big old-line tech companies -- many in California -- that are working on some potentially game-changing technology.

But how much of the game needs to be changed? That question seems heretical -- we'll have achieved renewable-energy nirvana when solar farms grow electrons 24/7, right? But it was raised by J.D. Sitton, chief executive of Infinia, a solar startup backed by prominent green-tech venture capitalist Khosla Ventures as well as eSolar founder Bill Gross' Idealab and Vulcan Capital, the Seattle investment firm run by Microsoft cofounder Paul Allen.

"There's a raging debate in the solar thermal business about how much is storage worth and how much it matters," says Sitton, whose, Kennewick, Wash., company, scored $3 million from the Department of Energy to create storage technology for its Stirling solar dish.

Resembling a large mirrored satellite receiver, Infinia's 21-foot-tall PowerDish focuses the sun on a Stirling engine suspended on an arm over the center of the device. The heat causes a gas inside the engine to expand and drive a piston that generates electricity.

The DOE grant -- and others Infinia has received from the federal government -- will allow the company to integrate storage capacity into the dish apparatus. Sitton says that will involve some form of molten salt that will store PowerDish-generated heat that can be released to drive the Stirling engine when the sun is not shining.