Delivering Massive Solar Power Gains

Phoenix-based Stirling Energy Systems plans to begin construction in 2009 on two $1 billion solar power farms on federal land in California's Mojave Desert northeast of Los Angeles and in the Imperial Valley east of San Diego, reports USA Today.

http://www.usatoday.com/printedition...terstitialskip

[hoon]

Solar and Stirlings, the perfect combination of low tech and high efficiency.

[LMagic007]

Originally Posted by Arnie28

Phoenix-based Stirling Energy Systems plans to begin construction in 2009 on two $1 billion solar power farms on federal land in California's Mojave Desert northeast of Los Angeles and in the Imperial Valley east of San Diego, reports USA Today.

http://www.usatoday.com/printedition...terstitialskip

Interesting concept having the power unit with the Solar dish as one unit. I can see this as having more cost effective scalability so far as solar thermal technology goes and thus perhaps suited to specific situations where you might start with one dish and then grow the installation as required. This might also for example be ideally suited for remote off grid applications.

With that said, I think that competing with solar PV might be a challenge. However thinking again, perhaps not too much, as storage is another key factor we need to way into the equation. i.e. PV battery storage cost vs. thermal storage. Anyway, the more options we have the better.

[brianidaho]

The interesting aspect is that Sterling cyce engine is a heat engine, and should be able to switch to different energy sources as the demand occurs. Solar when the sun is shining, combustable fuel (biomas or other) when required for "backup". This is unlike traditional PV cells which are useless when the sun don't shine. As LMagic said, this might be real appealing for off-grid situations, especially in forested areas with plenty of excess biomass to burn.

[LMagic007]

I know that the word "Sterling" forms part of the companies name. Are they actually using Sterling Engines though ? I did not pick up on that aspect from the article. i.e. the article refers to the origins of the Stirling Engine, but I cant actually see where they say that their design actually incorporates a "Stirling Engine". The article seems just a tad ambiguous on this point. Otherwise are we to presume that's what the article is inferring. i.e. that they will be using a "Stirling Engine". I'm not clear on this aspect.

[brianidaho]

The USA Today article is pretty vague on this, like most reporters they can't cover a technical issue competently. The Stirling Energy web site implies that the Stirling engine is a key part of what they are utilizing:

http://www.stirlingenergy.com/whatisastirlingengine.htm

I remember studying the Stirling Cycle back in college in the early '80s and seeing a demo motor run. They have typically been very inefficient compared to internal combustion engines. IIRC, the biggest issue is the rate of heat transfer through the cylinder(s) into the working gas of the engine. The use of alternative heat sources may make them competative, it will be interesting to see what happens. One nice aspect is that since you are driving a conventional generator with a mechanical (rotary) power source, producing AC power shouldn't pose the issues that photovoltaic's do on a large scale basis. In addition the AC output can be a proper sine wave, rather than the chopped square wave generated off an inverter.

[LMagic007]

Thanks for that. Yes you certainly do get the impression that it is using a Stirling Engine. The SES Solar Dish Stirling technology seems like an interestingly different concept from the steam turbine approach. I wonder if this technology might be better suited to lower temperature areas, due to the way in which the Stirling engine uses temperature differential to get useful energy, as opposed to absolute maximum heat.

I suspect this Stirling based technology would have it's own niche applications where it could perform better. I wonder if they can develop a heat storage tank approach for it also, so it can generate at night. I don't see why not. Another interesting technology to watch.

See also;

http://www.sandia.gov/news/resources.../Stirling.html