ok. im a botanist so forgive my ignorance.
but i have a few questions;
if the problem is to move from hot to cold, i got all the cold u want in
wisconsin. seems to me that a solar powered system would work up
here better than in the desert? specially in the winter where there is a
larger grade?
how much more efficent (cost and energy wise) is a PV than
a 'theoretical Stirling engine'? or isnt it?
my solar panel system could easily produce WAY more than i need.
seems to me that that could easily be ramped up and produce e' easier
than a PV?
if we could get a 10kw system on everyones house tops, we would
never need more e'. someone make me a system, im cold and tired of
burning old dead plants. lets get closer to the sun.
froggy
im cold. help
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stan.hornbaker
- Posts: 532
- Joined: Thu Jun 20, 2002 6:01 pm
- First Name: William S.
- Last Name: Hornbaker
Response to im cold. help
The problem is to move heat enery from a higher temperature source to a lower temperature sink and extract mechanical energy in the process.
A Stirling engine, or any other heat engine, does just that. The maximum efficiency of the Stirling is limited by the Carnot efficiency based on the values of the absolute temperatures. For the relatively low temperatures of a practical system for Wisconsin in winter the efficiency would be quite low 15 to 20 % maybe.
The PV system converts essentially all of the sunlight to electricity. Winter time in Wisconsin is limited in solar exposure due to latitude and hours of daylight.
Stay with a proven working system!
That would be an ideal solution but due to inherent design and practical considerations it isnt to be expeccted in the near future if at all.
A Stirling engine, or any other heat engine, does just that. The maximum efficiency of the Stirling is limited by the Carnot efficiency based on the values of the absolute temperatures. For the relatively low temperatures of a practical system for Wisconsin in winter the efficiency would be quite low 15 to 20 % maybe.
The PV system converts essentially all of the sunlight to electricity. Winter time in Wisconsin is limited in solar exposure due to latitude and hours of daylight.
Stay with a proven working system!
That would be an ideal solution but due to inherent design and practical considerations it isnt to be expeccted in the near future if at all.
Response to im cold. help
Billy is awfully pessamistic.
PV systems are generally 8-12% efficient, and they generally work better when cold. However, they get less sun in the frozen north, since all that solar energy has to travel through more atmosphere before it gets to you. A lot of that energy is lost to heating the clouds.
Stirling systems also work better when the cold side is colder. Again, since you get less sun energy per m^2 the hot side gets less energy, less hot, and less efficient. Stirling engines can be as much as 30-40% efficient, and use the same sun energy to drive them. The problem is that they're more complicated to build. You have moving parts in the engine, and you need a lot of sun on a small area to drive them. So you need mirrors or something to focus the sunlight, and they need to move as the sun moves across the sky. Its not as simple as slapping a few pannels on your roof, and wiring it into the house.
Also, anything with moving parts tends to break. So its not so much Stirling isn't the right way to go, just that its more complicated, bigger, and requires more maintenance. Hence, its harder to sell. Since there arn't any commercial manufacturors right now, anything you would build would be significantly more espensive, makeing Stirling a very poor choice in terms of watts per $.
It is do-able but we need more awarness, and support to make it happen. I'm trying not to sound as pessimistic as Billy, I'm not sure its happening. If we can get quantities on our sales, Stirling is a better alternative than PV, also, it doesn't start to glow after 50 years of use, which is a very good thing.
I hope that helps answer your questions.
PV systems are generally 8-12% efficient, and they generally work better when cold. However, they get less sun in the frozen north, since all that solar energy has to travel through more atmosphere before it gets to you. A lot of that energy is lost to heating the clouds.
Stirling systems also work better when the cold side is colder. Again, since you get less sun energy per m^2 the hot side gets less energy, less hot, and less efficient. Stirling engines can be as much as 30-40% efficient, and use the same sun energy to drive them. The problem is that they're more complicated to build. You have moving parts in the engine, and you need a lot of sun on a small area to drive them. So you need mirrors or something to focus the sunlight, and they need to move as the sun moves across the sky. Its not as simple as slapping a few pannels on your roof, and wiring it into the house.
Also, anything with moving parts tends to break. So its not so much Stirling isn't the right way to go, just that its more complicated, bigger, and requires more maintenance. Hence, its harder to sell. Since there arn't any commercial manufacturors right now, anything you would build would be significantly more espensive, makeing Stirling a very poor choice in terms of watts per $.
It is do-able but we need more awarness, and support to make it happen. I'm trying not to sound as pessimistic as Billy, I'm not sure its happening. If we can get quantities on our sales, Stirling is a better alternative than PV, also, it doesn't start to glow after 50 years of use, which is a very good thing.
I hope that helps answer your questions.
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kcbruzelius
- Posts: 1
- Joined: Sat Sep 16, 2006 8:20 pm
- First Name: Keith
- Last Name: Bruzelius
Response to im cold. help
I have no answer. I'm just interested in stuff, including heating with corn, but I have a couple questions.
It does seem that here in the North (MN for me) we have an abundance of cold in the winter, and we expend a lot of energy to heat our homes. So, what if we heat with corn, using that energy for the hot side of a large Stirling engine? Could we generate enough electricity for a whole year just by heating our homes?
Could small Stirling engines, located along the outside wall using the indoor heat and the outside cold, power led's to light our homes since we're heating them anyway?
It does seem that here in the North (MN for me) we have an abundance of cold in the winter, and we expend a lot of energy to heat our homes. So, what if we heat with corn, using that energy for the hot side of a large Stirling engine? Could we generate enough electricity for a whole year just by heating our homes?
Could small Stirling engines, located along the outside wall using the indoor heat and the outside cold, power led's to light our homes since we're heating them anyway?