Solar Power Stirling Engines

[skunk40]

Hello,

I've seen it mentioned a few times in this forum that Stirling engines
do not exist for solar power applications. Is this still the case?
I'm interested in integrating one for a residential application. Can
someone let me know why this hasn't been done before? Are there some
barriers that make PV technology more attractive?

Also, if there are commercially available 1-10kw systems, I'd love to
see the link. I've seen:
- Stirling Motor and
- http://www.epas-gmbh.com/ (are these guys still around? - website
seemed outdated)

Cheers,

Rich

[stan.hornbaker]

As far as I know that there are no or very few Stirling engines supplying commercial power from solar energy except for demonstration projects. These are large scale solar reflector arrays and a high temperature input Stirling. Still in R&D stages.

There are no commercial small Stirling-electric sets on the market and I do not expect them to become available in the near term. Long term availability will be dependent on a major breakthrough in design and application.

In the meantime you might find the links on of interest. Also the Stirling Engineering Society of USA at where you should find additional links to Stirling sites

[skunk40]

Any idea what the roadblocks are to creating a commercial small scale Stirling engine? Too hard to get a high input temperature? Too hard to keep the cool side cool?

Is there anything relating efficiency of electrical production to temperature differential for a typical engine?

Thanks!

Rich

[m35txxxx]

The key, from all I have read is simply this: VOLUME of energy. Gasoline and other fuels, contain vast amounts of energy in a very dense material - chemically converted during the burning process - so that engines like jets, turbines and internal combustion ones are economical - versital. Think of how far a 4000 to 8000 lbs car can go on a gallon of gas. For a simular Wind or Solar power system to generate that much work, the volume just has to be huge (compared to a gallon of gas) - and sometimes so would the engine in say a sail/solar array. So, the answer lies in two approaches - compression or mass (volume). What most are trying to do is use both - compress as much mass (energy) as possible to be able to generate work on the scale of the other fuel/engine combinations. This is what is happening with the solar arrays and Stirling engines out in the desert.

Just giving you a perspective as to why the Stirling as of yet is not as economically viable. The energy source is the problem, not so much the design or technical aspects of the Stirling engine itself. If you had a constant cold source of say zero degrees and a hot source of say 800 degrees - able to convert 10,000lbs of air between the two temps every 10 seconds say - then you have a SYSTEM that can provide lots of work. The key is this, it has to cost less (in money - not energy)to keep the cold side cold and the hot side hot than the NET value (economic not energy) of work performed/extracted/generated (it's gross value - minus all expenses).

The engine works, it is providing it a fuel source other than natural gas, gasoline and coal in a way that makes the total system economically viable that is the real issue. Which to date, has not been done with greate success.

Lee