Peltier Generating More Watts Than A Solar Panel

[mscoffman]

Hi Tacmatricx

What about a Sterling engine using -40C to +20C in cold climates, is it feasible using either the outside air to inside air difference?  Could a Sterling engine deliver enough power to heat one's house and keep the a Sterling engine system in motion and keep heating the house?

To that last statement No! Sterling engines are Carnot gas cycle engines
and will always have rather high internal losses. It might be just be
possible to use daily high and low temperatures combined with compressed
air to generate some useful levels of energy. But Carnot cycle efficiencies
are the bane of perpetual motion machines.

:S:MarkSCoffman

[billmehess]

Yea , I know my numbers were way off on this one, glad it's generated some bannering around though.
Always fun to talk to all of you great people!
Bill Mehess

[Poit]

Sorry to revive such an old thread... I just very interested in this topic...

so we have sterling engine vs. peltier vs. solar panels

1: sterling engine
2: peltier
3: solar panel

Wouldn't a peltier setup with large fresnel lens magnifiers with water cooled heat sinks + thermal compound (a crap load of these units, i.e 300 (only $3 on ebay per peltier module) be an ideal solid state electricity generator?

from what I have seen (someone posted the video here already http://www.metacafe.com/watch/1167872/alternative_electricity_energy_power_from_peltier/)... a single peltier unit can produce .9v @ 250mA albeit the heat source was from candles, BUT! with concentrated sun light, I believe you could get close to this heat.

So maths time:
to get 14v you would need to put 20 units in series (20x .7v = 14v) I say .7v because if peak is .9 im guessing .7 would be average.

So thats, 20 units in series to make 14v 250mA. so if you build 40 of these, wire them in parallel, you should get 14v @ 10A/h DC. average of 7 hours of hot sun would make that 70Amps.

Get a gel cell or a normal lead acid battery @ 12v 70Amp capacity. The entire setup would be very handy, especially if you re-wire the lights in your house to run off 12v.

For cost:
for individual purchases (ebay) it costs $3.85AUD per peltier. Now, im guessing that if you buy in bulk this price can be reduced to at least $2 each. so to buy 800 units would cost $1600. + heat sinks, fixtures, housings, and extra materials... im guessing thats an extra $400 at least.

so around the 2 grand figure.........  for 2 grand in solar panels can buy you ........... well its about $700 per 100Watt... and 100 Watt is about 8.3Amps.... so $1400.... hmmm I guess it might be cheaper...... crap... ive written all of this and solar panel works out cheaper??? waste of time?? or have i miscalculated?

[e2matrix]

Solar panels $1 to $2 per watt:  http://sunelec.com/

Your cost for solar is way high and I'm sure you won't beat it with peltiers unless you are in a very hot shaded environment. 

[CompuTutor]

I'm wondering why so many here
did not understand why both
the voltage and the currently increased.

The ammeter is essentially
a fixed resistance value,
just as Tacmatricx cited.

Exception being heat
from excessive current.

For a fixed resistance,
when the voltage rises,
the current must too.

Ideally the ammeter should
be maxing-out the peltier
as far as current goes,
but the ammeter's resistance
is not low enough to do so.



So as more peltiers are added in series,
the voltage across ammeter's resistance
raises until the peltiers maximum current
across a load is finally achieved.

At a certain number of peltiers,
the voltage will have raised enough
to utilize the maximum current out.

Then the current curve will level off.

Put that digital meter across the ammeter only
and measure the ammeter's internal shunt's resistance.

You'll find it is not low enough
to achieve the maximum current
from a single peltier is all.

Ideally,
if a known value of load resistance was known,
like a light bulb, motor, or other steady value.

Then a series set of peltier/solar cells
should be added one at a time until
the best utilization of them occurred.

Then upon knowing that (as example),
five units achieved maximum output.

Then additional peltier's/solar's units
should attached grouped into series
sets if five units.

Then each set of five units
is then added in parallel to
the existing first string.