Leveraging Solar Power

[BigBoyJoe]

I've recently began thinking about the possibilites of using a two-cylinder stirling engine and solar panels to produce viable energy but with a twist. make a unit, lets say 3x3 and 6 feet high and have it halfway into the ground. By having the hot end of the unit in the ground, and have the solar panels (that will be on top of the unit of course) power a heater that will go around the bottom of the unit and into and make direct contact with the hot end of the stirling cylinder. One more thing can be done to improve the effeciency of the model, on the cold side (near the top) have some heat sinks along with fans that will move when the stirling engine moves, the faster the engine, the faster the fans will go keeping the temperature differance at a maximum. Also a good regenerator is in order as well.

Does this sound feesible or is this one of those "It could, but barley not worth the effort" kind of deals.

I hope production of such a unit can be cost effective and not kill the viablility, sure it will still be in the 4 figure range, but hopefully no more than $5000 when everything is said and done.

Thoughts?

[BigBoyJoe]

One more thing, by having the unit halfway in the ground, the ground can store the excess heat and when the solar panels power starts to wane, the latent heat stored in the ground can still have the unit moving for a while longer. Perhaps putting some sort of heat absorbant material around the bottom can help this further.

I think thats everything, I hope-

[skravlinge]

Power the heater, with what. If you mean you should use an electrical resistant heater to feed a sterling, I think you are better off feeding an electric motor.

Feeding a sterling using the sun will best be done  transforming the solar straight to heat using  hyperbolic mirrors or passive solarpanels. With hyperbolic mirrors I think it would be possible to built quite big electric plant in places like desserts in South USA.

[BigBoyJoe]

Perhaps, but I'm not looking to instantly start the stirling. The idea is that the solar panel (thats on the roof of the unit) will provide enough power to heat up those wires and warm up the ground(as well as the hot end of the stirling), and the ground will stay warmed up a while after the sun has gone down.

If I'm not mistaken, the ground is a good insulator and it likes to keep the hot or cold in. but then again, I may be wrong. It's all how the unit is placed in the ground and what type of dirt surrounds the in-ground unit.

When the photo uploads work, I'll post the image concept for the unit.

[ghurd]

It would probably be better to use a heat collector panel instead of a solar electric panel.  Electric solar panels are typically only 8-14% efficient. I would hope a heat collector panel would beat that easy, and for a lot less money. I don't know about the numbers for them, someone else may.  $500 doesn't get much PV, but would build a 'lot' of heat collectors.  Look under the heat section.

G-

[BigBoyJoe]

Here's the concept image, its the front view, and I'm sure there are ways to optimize such a unit. Maybe I can have the dimensions of the beta unit be 1'x 2'x 3' (Length/Width/Height) just to see if a 1' x 2' solar panel can produce enough "warm up" power.

though a parabolic mirror would be more effecient, I'm just looking for a decent power output. I'm looking at a 24"x37"x.5" panel that will put out (In full sun of course) 17 volts @ 2 amps. 35 watts going through a system with low resistance(but not too low) will heat up some wire rather quick.

So within a couple hours the unit should be hot enough to put out some nice power, and the surrounding ground should keep it that way for a while longer after the sun has set. Even if I need 2 of these panels to get things going quicker, it may still be worth the exersize.

[BigBoyJoe]

[BigBoyJoe]

Here's a better image on the unit. it's a side view this time...