# Converting heat into energy [closed]

I'm currently building a custom desk. In this desk I will also build-in a small part with a custom electronic panel to provide power to USB devices.

As my gaming pc generates a lot of heat and the panel will generate some too, I was thinking about doing something with this heat. I read another post on this physics part of stackExchange where they say it isn't efficient and you would need a alot of cold air supply.

As I live in Belgium, most time of the year there is enough of cold air, just outside of my window. Another thing is, it doesn't have to be super efficient. If I could just generate enough current to give power to one or more USB connectors or store it in a battery, I would be happy.

Is it possible to create enough energy for my USB, if I got a hot air flow of 50°C and a cold air reservoir of 0-10°C? Follow up question, is it practically possible?

USB works at 5 Volt at a current from 0.5 to 5 Amps.

Other (possible?) options I found was using thermocells and thermocouples.

## closed as off-topic by Qmechanic♦Feb 1 '14 at 15:52

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• What is the question here? – Carl Witthoft Dec 17 '13 at 20:23
• Sorry if I didn't make myself clear. Is it possible to generate enough power for my USB connector if I got hot air of approximately 50°C and cold air from arround 0-10°C? Second part would be, is it practically possible? – Wesley De Keirsmaeker Dec 17 '13 at 20:29
• If you search for thermoelectric generators, you will get lots of sources. All I saw want much hotter air than you have, but you could look around. – Ross Millikan Dec 17 '13 at 20:34
• But what is the most optimal way to do this? And is it possible to calculate how much energy I could optimally and minimally generate with given temparatures? Let's say with the SEEBECK effect. I have no clue how to interpret the formula on wikipedia. – Wesley De Keirsmaeker Dec 17 '13 at 21:02
• Ok, never mind. After checking some videos of homemade thermo electric generators, it's obvious my situation will never provide enough current and voltage for my USB. One created a voltage of arround 0.5V with a flame but with hardly enough current. Maybe I will create one for fun to check if it could light up some LEDS. Thanks! – Wesley De Keirsmaeker Dec 17 '13 at 21:24