photo: green wombat
California utility PG&E today will announce an agreement to buy 553 megawatts of electricity from a solar power plant to be built by Israeli company Solel in the Mojave Desert. That’s enough energy to light about 400,000 homes. It’s the largest deal of its kind, just edging out Southern California Edison’s (EIX) 2005 agreement to purchase 500 megawatts of solar electricity from a power plant to be built by Stirling Energy Systems in the Mojave. Solel’s 6,000-acre Mojave Solar Park is set to begin operating in 2011. The Solel station will be located near nine existing solar power plants built in the 1980s by Israeli company Luz (photo above) that continue to supply 354 megawatts of green energy to Southern California. It’s an appropriate locale. When Luz went bankrupt in the early ’90s after solar energy tax breaks evaporated and natural gas prices fell, Solel picked up the company’s parabolic trough technology. (Luz, meanwhile, has been revived as BrightSource Energy, which is negotiating a 500-megawatt deal with PG&E.) Solel will use a more advanced version of the solar trough for its Mojave project, which will contain 1.2 million mirrors and 317 miles of vacuum tubing. Just this week the company announced that it had upgraded the old Luz plants – most of which are now operated by FPL Energy (FPL) – with 30,000 new solar receivers.
Solar trough power plants use parabolic mirrors to track the sun and heat tubes of liquid to produce steam that drives electricity-generating turbines. The efficiency of solar troughs is quite a bit lower than other utility-scale technologies under development, but it’s tried and true and that’s what apparently attracted PG&E (PCG), which emphasized it was "commercially-proven." The San Francisco-based utility has been hedging its bets, signing deals with companies developing a variety of solar technologies. BrightSource Energy, for instance, will deploy fields of mirrors to focus the sun’s rays on a tower containing a water-filled boiler to create steam to drive a turbine. PG&E has also signed a deal with San Francisco solar startup GreenVolts to build a two-megawatt "plug-in" power plant that will use concentrating photovoltaic technology to produce electricity near urban areas.
PG&E’s deal with Solel is another sign that California has become a proving ground for Big Solar technologies. Stirling Energy Systems uses a giant solar dish to concentrate the sun’s rays on a Stirling heat engine. As hydrogen inside the engine expands it drives pistons that generate electricity. The Stirling dish is far more efficient than the solar trough but it has never been deployed on a large scale. Stirling Energy’s deals with Southern California Edison and San Diego Gas & Electric (SRE) have options to produce up to 1.75 gigawatts of solar electricity. Add in the Solel 25-year contract and – assuming PG&E reaches a final deal with BrightSource Energy – California potentially could have nearly three gigawatts of utility-scale solar power online within the next five or six years.
Green Wombat 
Todd,
great column. I appreciate the all in one place reference to other large scale solar projects and the info on the upgrades at the FPL site.
It would be useful to also have information on the efficiency, capacity, and cost of each of these actual and proposed projects, and what the contracted sales price of power generated is, and information on the subsidies for the projects.
Good article, but it lacks sufficient technical information; are they using a molten salt system, does it provide for thermal storage, what is the life cycle cost analysis, etc..
PVP likes to get the details, and it enhances the success of the active solar industry to get good comps out there relative to PV cells and traditional generation.
D Missey
Agreed. Would love to get some more hard numbers on cost, price, efficiency, dimensions of system, etc. to work with. Are we developing a critical mass yet?
It is important to point out the fact that solar thermal introduces a critical option to Solar PV because reflector technology does not require silicon based technology. PV on the other hand competes with the computer industry for Silicon which adds cost, eventhough thin film uses less silicon than standard PV. On the other hand thin film is less efficient and uses more space. Whne competition for silicon subsides, the cost of PV will continue to go down. There is and important distinction to be made as well. PV is far more portable at the present time. But smaller solar thermal systems are also available through a company called Industrial Solar Technology, located in Colorado. The company has been in existence for more than 20 years and supplys home units as well as industrial units for heating water to produce steam to drive turbines.
We need more solar power not atomic
we need more solar power not atomic