Peltier as a generator
AC/DCdude17
I have conducted an experiment using a 9cm2 peltier as a generator
and this is my date:
side A: heated in boiling water
side B: cooled with a heat sink cooled by Freon 12 and dry ice.
open circuit voltage 2V
short circuit current: 300mA
maximum output power into a 12ohm resistor
V²
watt = ----
R
V under load: 2.2V
R=12ohms
(2.2²)/12= 400mW.
With a pan filled with boiling water and constant cooling with dry
ice and Freon 12, this is waaaay far from practical. The gas used to
heat the water cost more than the energy produced and I am disregarding
the cost of Freon and dry ice.
Gerry Schneider
That's some nice work you did there - hooked something up and got it to
work - congrats!
I'm assuming the voltage didn't actually go up when you connected a load -
just a lot of variation in readings over the course of the experiment?
The efficiency numbers look much more palatable if you use "free" temp.
differences, like ambient room air convection cooling for cold and waste
heat from a gas lantern for hot. That's what the Soviet government used to
provide for people in the non-electric boonies, to power radios for
listening to (what else) the Official Party Line. Unfortunately, the
Peltier coolers aren't designed to use really high delta T, where the ouput
power would get adequate.
Regards,
Gerry
Spehro Pefhany
> I'm assuming the voltage didn't actually go up when you connected a load -
> just a lot of variation in readings over the course of the experiment?
Maybe there's something wrong with his meter? ;-)
Best regards,
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AC/DCdude17
Gerry Schneider wrote:
> AC/DCdude17 wrote:
>
> > To those whose been following the "peltier diode" thread:
> >
> > I have conducted an experiment using a 9cm2 peltier as a generator
> > and this is my date:
> >
> > side A: heated in boiling water
> >
> > side B: cooled with a heat sink cooled by Freon 12 and dry ice.
> >
> > open circuit voltage 2V
> >
> > short circuit current: 300mA
> >
> > maximum output power into a 12ohm resistor
> >
> > V²
> > watt = ----
> > R
> >
> > V under load: 2.2V
> > R=12ohms
> >
> > (2.2²)/12= 400mW.
> >
> > With a pan filled with boiling water and constant cooling with dry
> > ice and Freon 12, this is waaaay far from practical. The gas used to
> > heat the water cost more than the energy produced and I am disregarding
> > the cost of Freon and dry ice.
>
> That's some nice work you did there - hooked something up and got it to
> work - congrats!
> I'm assuming the voltage didn't actually go up when you connected a load -
> just a lot of variation in readings over the course of the experiment?
The voltage dropped significantly when I loaded with 12ohm resistor just as
I expected.
>
>
> The efficiency numbers look much more palatable if you use "free" temp.
> differences, like ambient room air convection cooling for cold and waste
> heat from a gas lantern for hot.
Strangely this peltier generates very generous 100µA when just left in the
air. Considering the heat sink is black, which absorbs IR, it provides enough
difference to actually create a current. Open circuit voltage in this
condition is 5mV. It changes a bit when I shine my flashlight at it.
Eddie (Adel) Rebehy
Place the hot side in a pan or pot with the heatsink (cool side) exposed
upward. You can use some heatsink compound to seal the peltier to the pot
but as many of these compounds have arsenic in them I wouldn't use the pot
again for food :) place it under a low flame and do your tests again without
cooling with spray. Just a stove flame and ambient air to give you your heat
difference. No boiling water either.
I'm not sure what the peltier will withstand in the way of heat but the
above test is what I am interested in having the results for.
Regards
Eddie
AC/DCdude17 <bi_tee...@mailandnews.com> wrote in message
news:3AD41AC1...@mailandnews.com...
Adam Yudelman
open circuit voltage 2V
short circuit current: 300mA
...
V under load: 2.2V
R=12ohms
Adam
AC/DCdude17
Adam Yudelman wrote:
> You wrote:
>
> open circuit voltage 2V
> short circuit current: 300mA
> ...
> V under load: 2.2V
> R=12ohms
>
> Adam
My bad. I meant to write 2.5V for open circuit voltage. Thanks for poiting
out.
Andre de Guerin
Yeah, you didn't expect to get something for nothing, did you ? <g>
tom
I'm wondering what he did with the Freon? Just blew
it out of a hose pointed at it?
Allowing the gas to escape into the great blue yonder
to chew at our Ozone layer eventually killing all of humanity...
Andre de Guerin wrote:
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see it at http://www.quadjoy.com
Robert Richter
>To those whose been following the "peltier diode" thread:
>
> I have conducted an experiment using a 9cm2 peltier as a generator
>and this is my date:
>
>side A: heated in boiling water
>
>side B: cooled with a heat sink cooled by Freon 12 and dry ice.
I'm glad to see you defying the DuPont scam on freon (which I don't believe
does a damn thing to the ozone); just don't admit it to the whole world and
keep up the good work.
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Gerry Schneider
> Good work. If you are still keen then try this:
>
> Place the hot side in a pan or pot with the heatsink (cool side) exposed
> upward. You can use some heatsink compound to seal the peltier to the pot
> but as many of these compounds have arsenic in them I wouldn't use the pot
> again for food :) place it under a low flame and do your tests again without
> cooling with spray. Just a stove flame and ambient air to give you your heat
> difference. No boiling water either.
>
> I'm not sure what the peltier will withstand in the way of heat but the
> above test is what I am interested in having the results for.
Easy on that flame! The Melcor data sheets say the internal solder melts at 135
deg C !!! These particular thermoelectric coolers are definitely not meant for
life as high-temp electric generators.
Gerry
AC/DCdude17
tom wrote:
> I'm wondering what he did with the Freon? Just blew
> it out of a hose pointed at it?
Yup in liquid form. Used about a pound of it or one whole can.
>
>
> Allowing the gas to escape into the great blue yonder
> to chew at our Ozone layer eventually killing all of humanity...
Umm.. I think one pound is very small compared to how much Freon 12 is
released into atmosphere everyday. It is known that one teen releases about
twice as much Freon 12 as two adults since they are more prone to
collision. When cars made before 94 is wrecked, it will release all the
refrigerant into the atmosphere. Sure "deliverate" refrigerant releasing is
punishable, but accidental isn't defined. I'd say teens release more than
twice considering they tend to drive older cars. Hell drunk drivers who gets
intoan accident should be fined for releasing ozone depleting substance too.
Chris Pflieger
--
Chris Pflieger
Design Engineer
Touchplate Technologies, Inc.
Eddie (Adel) Rebehy
Gerry Schneider <ger...@sympatico.ca> wrote in message
news:3AD6A6E4...@sympatico.ca...
> Easy on that flame! The Melcor data sheets say the internal solder melts
at 135
> deg C !!! These particular thermoelectric coolers are definitely not meant
for
> life as high-temp electric generators.
>
> Gerry
I'm sure you are correct Gerry. Still there must be a way to do this. All I
need is to generate enough power from the heat given off a stove to turn a
small DC motor. Any suggestions? Are there any other devices besides a
peltier?
--
- -
Eddie (Adel) Rebehy [EE]
www.IPinventions.com
1% inspiration is the easy part.
99% perspiration doesn't include sitting in the sauna.
William L. Bahn
AC/DCdude17 wrote in message <3AD6A649...@mailandnews.com>...
>
>
>tom wrote:
>
>> I'm wondering what he did with the Freon? Just blew
>> it out of a hose pointed at it?
>
>Yup in liquid form. Used about a pound of it or one whole can.
>
>>
>>
>> Allowing the gas to escape into the great blue yonder
>> to chew at our Ozone layer eventually killing all of humanity...
>
> Umm.. I think one pound is very small compared to how much Freon 12 is
>released into atmosphere everyday. It is known that one teen releases
about
>twice as much Freon 12 as two adults since they are more prone to
>collision. When cars made before 94 is wrecked, it will release all the
>refrigerant into the atmosphere. Sure "deliverate" refrigerant releasing
is
>punishable, but accidental isn't defined. I'd say teens release more than
>twice considering they tend to drive older cars. Hell drunk drivers who
gets
>intoan accident should be fined for releasing ozone depleting substance
too.
Gee, what an attitude. It's OK for you to deliberately release "about a
pound of it" since it is "very small" compared to how much is released
everyday. Yet the vast majority of releases are on that order - it is the
cumulative effect of a whole lot of small releases that make up the amount
that is released every day. But none of that should affect you because you
are too self-absorbed and self-important to hold yourself to the same
standards as everyone else.
Gerry Schneider
> Gerry Schneider <ger...@sympatico.ca> wrote in message
> news:3AD6A6E4...@sympatico.ca...
> > Easy on that flame! The Melcor data sheets say the internal solder melts
> at 135
> > deg C !!! These particular thermoelectric coolers are definitely not meant
> for
> > life as high-temp electric generators.
> >
> > Gerry
>
> I'm sure you are correct Gerry. Still there must be a way to do this. All I
> need is to generate enough power from the heat given off a stove to turn a
> small DC motor. Any suggestions? Are there any other devices besides a
> peltier?
For sure. Thermoelectric cooling (TEC) devices are meant to be efficient at low
delta T. Thermoelectric generating (TEG) devices are designed for flame-type
environments at high delta T. Both are Peltier/Seebeck devices, but different
materials and construction, and both are readily available. A Google search will
find what you want.
Gerry
Eddie (Adel) Rebehy
Thank you Gerry. I found the following site useful after taking your advice.
http://www.hi-z.com/websit02.htm
Robert Richter
> By the way... asshole Richter... haven't you been following the
>Space Shuttle data gathering practices? DuPont has nothing to do with
>the determination that chlorinated gasses break up ozone, and the
>"Ozone Layer" in our upper atmosphere... Duh! Satellites first noted
>it ten years earlier. Are you just a little lost puppy, or what?
>
>
>TopQuark...
My chemist was a refrigeration technician who I programmed a PLC for to
control his compressors, solenoids, etc; not exactly an unbiased chemist
with
a PhD in this area. I am not a chemist myself.