Perhaps all these entries about solar are fitting, given that it’s August and many of us are soaking up the rays on cottage docks – or, if you’re like me, sitting behind a computer in an office.

Sigh.

Much of what I’ve been writing about lately has been about solar PV, including new projects, undersupply in the industry, and government policy. But I haven’t really touched on solar thermal technology, which is actually much more efficient than solar PV in terms of energy production.

Most solar thermal systems are for heating applications that would displace the requirement for natural gas, oil or electric heating. That is, they’re not typically associated directly with electricity generation. But a new project being pursued in California is expected to result in the world’s largest solar power plant — a massive 500-megawatt facility that could expand to 850 megawatts.

It’s all part of a partnership between Southern California Edison and Phoenix-based Stirling Energy Systems, which would install 20,000 dishes across 4,500 acres of property near Victorville, California between now and 2010. The 37-foot diameter dishes are solar collectors, which use 89 parabolic mirror facets to focus the sun’s rays on an oil-drum sized engine systems.

“The Stirling dish technology converts thermal energy to electricity by using a mirror array to focus the sun’s rays on the receiver end of a Stirling engine. The internal side of the receiver then heats hydrogen gas which expands. The pressure created by the expanding gas drives a piston, crank shaft, and drive shaft assembly, much like those found in internal combustion engines but without igniting the gas. The drive shaft turns a small electricity generator… The process requires no water and the engine is emission-free,” according to Renewable Energy Access. 

The concept, called “concentrating solar power,” or CSP, is ideal for utility-scale solar systems. You need a lot of acreage to put together what is essentially a solar field, so obviously the logistics of doing such a project are tricky. But obviously not insurmountable.

Alan Fohrer, CEO of Southern California Edison, said there will be no state subsidy for the contract and that ratepayers will get reasonable pricing, “because tests have shown the Stirling dish technology can produce electricity at significantly lower costs than other solar technologies.”

Hey, whatever turns your crank — literally. This is what distributed renewable energy generation is all about. The more diversity of systems the better. It’s about matching the right technology for the right application and geography. This will be a fascinating project to watch as it progresses. 

This entry was posted on Thursday, August 11th, 2005 at 11:31 pm and is filed under Main Page. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.