Popsci: New Alloy Can Convert Heat Directly Into Electricity

[Xist]

I bought a subscription to this and two other magazines on Cyber Monday. I believe that I have received a total of six copies. Anyway, while trying to find something else I ran across this. Let me tell you, I have dreamed of this technology!

New Alloy Can Convert Heat Directly Into Electricity | Popular Science

I do not know for sure, but I have long believed that an air conditioner actually produces more heat than it cancels, while heat is energy, and I have wished that I could figure out how to make use of that energy. We have plenty in Arizona. My laptop gets too hot, I cannot touch my steering wheel in the summer, and not only are solar panels inefficient, they get hot, too! Still, I hate thinking that it might be ten or twenty years before anything useful comes out of this.

[jamesqf]

Trouble is, you can't convert temperature into energy, only temperature differences.

[Xist]

Isn't that how Stirling engines and peltiers work?

[ConnClark]

Originally Posted by Xist

I do not know for sure, but I have long believed that an air conditioner actually produces more heat than it cancels, while heat is energy, and I have wished that I could figure out how to make use of that energy.

An air conditioner does create more heat than it cools. It releases the heat of the electricity or mechanical work plus the heat it removes from the cool side.

Unfortunately trying to recover energy from the heat released is not easy or significant because of the low temperature differentials you have to work with.

To summarize the first, second, and third laws of thermal dynamics: You can't win. You can't Break even. You can't get out of the game.

[ConnClark]

Originally Posted by Xist

Isn't that how Stirling engines and peltiers work?

Stirling engines and peltiers work by sitting between two temperature differentials. As the heat flows through them from hot to cold they harness some of that energy. In short they are like windmills for heat. Windmills use air to work, but if the air isn't flowing your not going to get anything out of them.

[Szegedin74]

@ConnClark -- dig your summary of the laws of thermodynamics. Care to elaborate? As a non-scientist I've always been faschinated with the second, which gets discussed in social science.

[Xist]

Originally Posted by ConnClark

In short they are like windmills for heat.

Whose tagline says "That's not how windmills work!"?

When I was in elementary school we had some assembly where a man had a girl hold a tile made from sand. He said it was like what what the space shuttle used. He put a torch to the tile and asked the girl to tell us if she felt the heat.

Could you put insulation between a heat source and the ambient air and then use that differential?