Is it possible Construct a Striling Engine Capable of generating 5KWp as shown here?

System
System Posts: 2,511 admin
in General Solar Power Topics #1
Hi,

Is it possible Construct a Striling Engine Capable of generating 3-5KWp similar to the one shown here in this video? The Stirling can be Hooked up to an Alternator or a Generator...

http://www.youtube.com/watch?v=-7YK3Gd0thg&NR=1

The idea is to use a Large enough Frensel Lens to generate the Heat Necessary to power the Stirling and generate Electricity...

If possible, any idea on

1. What the size of the Fresnel should be to generate enough heat? I know that a 36"x36" Frensel or similar lens size can generate more than 2000F degrees of heat.

2. What kind of Heat is necessary to run the Stirling of this size to generate 3-5WKp?

3. At what RPM will the Striling should run?

4. What is the approximate output in Horsepower generated by the Stirling?

5. What would be a reasonable sized Alternator to hookup to this?

Thanks for your help.
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Comments

  • System2
    System2 Posts: 6,290 admin
    #2
    Re: Is it possible Construct a Striling Engine Capable of generating 5KWp as shown he

    Not sure if this is the right forum for those questions but the wide variety of contributors to this forum may prove me wrong. I did watch the video, making volts is easy, making amps (usable power) is difficult. Have you checked out www.otherpower.com ? Those guys are nuts (in a good way) and do some amazing things for micro scale power generation!!

    Cheers,

    Bad Apple
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #3
    Re: Is it possible Construct a Striling Engine Capable of generating 5KWp as shown he

    I'm an engineer, and I am here to help (as my wife kicks my leg telling me that nobody really cares)...

    Here are some good sized Stirling Engine solar collectors (these are 25 kW output generators)... I think So. Cal. Edison or somebody has a big contract to build a field full of these (my 2 cents, I think this program is a tax dodge--I am not sure that this will ever be build)... I posted more information here a year or so ago...

    Anyway, your question... Around 30% efficient from sun to mylar reflector to motor to alternator to grid...

    So, if you want a 5kW output (746 watts per HP or ~6.7HP generated, probably over a 10 HP rated Stirling motor)...

    Area--full noon time sun is roughly 1kW per meter^2...

    5kW * 1/30% eff * 1/1kW per m^2) = 16.67 m^2 or 179 sq.ft.

    Or about 13.3'x13.3' foot reflector... To account for losses, other than noon sun, dust, etc., you might want ~50% more sq. footage.

    A 36" by 36" Fresnel lens will focus less than 1kW of heat and generate less than 300 watts of electricity (under ideal settings with ~30% efficiency--which none of us will ever be able to obtain using a Fresnel lens and small Stirling engine/alternator--maybe 10% efficient or less than 100 watts.).

    How fast--depends on how many poles the alternator has... A two pole would need to spin at 3,600 RPM for 60 Hz. A four pole, 1,800 RPM. An 8 pole would be 450 RPM, etc... (IIRC, excluding using gears/pulleys, etc.).

    You might end up wanting to do an alternator rotating not at any fixed RPM (like a small grid tied wind turbine)--but rectify the AC frequency to DC and use the equivalent of a Solar Grid Tie Inverter to convert your high voltage to Grid AC (plus you have the safety of a UL listed inverter).

    You can look on the web for those small Stirling motors like you saw in the video.

    Stirling motors fascinate me (same with steam)--but I for the life of me cannot believe the work the way they do (obviously, they do...).

    In the end, I don't think you will ever achieve your goals unless you have a DOD/Green Grant hiding somewhere...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • rplarry
    rplarry Solar Expert Posts: 203 ✭✭
    #4
    Re: Is it possible Construct a Striling Engine Capable of generating 5KWp as shown he

    Another consideration is that all rotating machinery will break down. A pv solar panel will just keep on working as long as it is not physically damaged. If this is going into a remote location where the indiginous population may not have the skill or parts available to maintain a piece of rotating machinery, then I would think that a few solar panels would make much more sense. Just my 2 cents.
    Larry
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  • System2
    System2 Posts: 6,290 admin
    #5
    Re: Is it possible Construct a Striling Engine Capable of generating 5KWp as shown he

    This uses Solar Thermal:
    http://www.solarandthermal.com/(3)product/3.customer/3.residential/333_residential.htm
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