6 Cents Per kWh: World's Largest Solar Project Unveiled
by Justin Thomas, Virginia 
on 08.14.06
Stirling Energy and Southern California Edison have announced they plan to construct a 4,500-acre solar generating station in Southern California. When completed, the proposed power station would be the world's largest solar facility, capable of producing more electricity than all other U.S. solar projects combined. They promise a cost of electricity of 0.06$/kWh.
The dish collectors are unique because they make no use of photovoltaics, instead they use mirrors to focus the sun's rays on a Stirling engine. This heats hydrogen gas inside the engine 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 entire energy conversion process takes place within a canister the size of an oil barrel. The process requires no water and the engine is emission-free.
The 20-year power purchase agreement signed today, which is subject to California Public Utilities Commission approval, calls for development of a 500-MW solar project 70 miles northeast of Los Angeles using innovative Stirling dish technology. The agreement includes an option to expand the project to 850 MW. Initially, Stirling would build a one-MW test facility using 40 of the company's 37-foot-diameter dish assemblies. Subsequently, a 20,000-dish array would be constructed near Victorville, Calif., during a four-year period.
"At a time of rising fossil-fuel costs and increased concern about greenhouse-gas emissions, the Stirling project would provide enough clean power to serve 278,000 homes for an entire year," said SCE Chairman John Bryson.
Although Stirling dish technology has been successfully tested for 20 years, the SCE-Stirling project represents its first major application in the commercial electricity generation field. Experimental models of the Stirling dish technology have undergone more than 26,000 hours of successful solar operation. A six-dish model Stirling power project is currently operating at the Sandia National Laboratories in Albuquerque, New Mexico.
"We are especially pleased about the financial benefits of this agreement for our customers and the state," said Alan Fohrer, SCE chief executive officer. "The contract requires no state subsidy and provides favorable pricing for ratepayers because tests have shown the Stirling dish technology can produce electricity at significantly lower costs than other solar technologies."
Tests conducted by SCE and the Sandia National Laboratories have shown that the Stirling dish technology is almost twice as efficient as other solar technologies. These include parabolic troughs which use the sun's heat to create steam that drives turbines similar to those found in conventional power plants, and photovoltaic cells that rely on an expensive and increasingly limited raw material stock.
Follow @TreeHugger on Twitter & get our headlines with @TH_rss!
Thirsty for more? Check out these related articles:
- 7 Great Weekend Solar Power Projects
- How to Use a Solar Cooker: What Works and What Doesn't
- How to Use a Solar Oven: Beans and Rice Recipe
- Did You Know Saving Water = Saving Electricity?
- 5 Reuses for Altoid Tins
- Create a Go Green Plan: Follow Wa$ted!'s Salon Example
At an eventual 4500 acres this project isn't going to blight too large an area. 4500 acres is only seven square miles in area.
4500/640 = 7.03 sq miles.
Think of how much strip mined coal this plant won't need to be mined. I hope it lives up to its billing.
There's not much to "blight" outside Victorville, except desert and big hills.
Bravo! Fill up the desert with mirrors and Stirling engines to capture the sun!
This is A YEAR OLD, and I believe it was on Treehugger then as well.
Ben: Note that this about the newly announced partnership between Sun Edison and Stirling Energy.
I want one for my house, maybe another for the top of my car.
Not exactly breaking news, this agreement is from October 2005.
They just got around to signing the papers August 9th (the usual lag between making an agreement and the lawyers signing off on inking the deal).
I second Ben's comment, this is recycled info from Treehugger last year.
This project has been covered just about everywhere already. How about publishing some new information?
(btw, consider refering to this as a Solar Dish powered Stirling Engine instead of a "Stirling Dish")
You won't be able to put one on your house unless you're willing to spend $200,000 on one of these guys.
Eminently more sensible, it is, to harvest sun from desert than ruin rivers trying to make desert farmland!
Wouldn't it cause more heat in the area because of the heat generated?
I don't think they actually generate heat. I believe they just focus the light/heat on the stirling engine.
What's you got that's new and working TODAY... Yep the web has got scores of crap full of "pie in the sky" promises, of break throughs, to come,,,,,,, tommorrow. It's all the same BS I've been reading my whole life. What's it going to be like in the future? I'll bet it's more like today than you said it would be yesterday. Blaa, Blaa , I'd also bet money that the guy who invented a car that runs on water still uses gas in the car he drives today!
10 billion of these would power 3 to 4 present day global energy requirements including providing extra energy needed to store energy (hydrogen, batteries, ect)! Spaced every 100 feet, 3.6 million square miles of desert would be needed out of a total od about 10 million. With obvious mass production tech, it's doable!
As for heat generation, the light is reflected onto the stirling engine which converts some 28% or so of it into electricity. This and the fact that the ground would be shadowed to some extent would cause some (miniscule) cooling effect on the planet. The major cooling effect comes from the stopping of GW. If SCE could really get the kWh down to 6 cents, Then the solar dish must cost ... well, figure 25% capacity factor times 25 KW times 8760, (hours in a year)=54,750 kWh/year apiece. X .06 = only $3,285 per year, payback, say 10 years, therefore about than 30 grand apiece with these very simplified figures!
You're wrong to conclude that this would not heat up the desert.
Desert sand must reflect more than just 28% of the energy that strikes it.
This dish will convert ALL the light it captures into heat, except for 28%. Remember, the collector is black and designed for maximum efficiency of converting the light into heat to run the Stirling engine. Furthermore, that 28% of electricity will all become heat at some point.
But at the end of the day, it's probably more efficient total than using coal, gas or even nuclear in terms of generating heat.
The additional heat might very well increase air turbulence - it might make sense to integrate windmills into the solar farm as well.
Does this project exist?
Great idea,
What are the plans for power at night?
Will there be study of temperatures in the area-day and night after construction for changes in the desert climate?
If the deserts were covered with conventional "black" solar panels, the heat effect alone would have to be considered. Imagine black deserts (as seen from space), no good, also realize that such needs to be dark in color to absorb more for the transfer into juice.
with mirror, (from space) the deserts would look like the sky.. and thus would reflect more light back into space to compensate for melting glaciers.
On such a planetary scale, the abedo has to be considered (and not allowed to be an excuse for the retro's to downplay).
Now, we must also realize that the heat effect alone will always trickle down into the biosphere as the laws of thermo..says, thus we must try to match that of desert sand, just to keep it below the norm. No matter how efficient, 100% of our "perfect" energy source will still turn into heat within this biosphere (even led lighting produces heat), thus on such a large scale (as I hope to see), solar has to be "really light green" to not allow enviro retro's to battle against!. If, say the total generating power of the "mirrors" were more than enough for a certain day, the mirrors would have to (in part) "turn off" and reflect back into the sun (instead of the generator). That would more than compensate for melting glaciers.. . on such a large scale...
Hence GW reversal!