Case = heat = energy?

[James Bond]

Is there no 'good' way to generate energy from heat?

Would it not be possible to use the heat from inside a desktop case to ones advantage in order to generate energy to "fuel" a computer?

Just a thought...

 

[Matthias99]

Originally posted by: Tizyler
Is there no 'good' way to generate energy from heat?

I'm not sure what you mean, as most electrical energy is generated from thermal energy (except for things like hydroelectric or wind power, where kinetic energy is harnessed, or some kinds of solar cells).

Would it not be possible to use the heat from inside a desktop case to ones advantage in order to generate energy to "fuel" a computer?

Use your computer's waste heat to power your computer? Sure! Just find a way around the second law of thermodynamics and you're all set.

No free lunch. The heat in your case is being produced by the computer itself (which is also what is consuming the power)... you can't get more energy out of the system than you put in. You might be able to exploit some of the waste heat to do some useful work (as is done in cogeneration plants), but the amount coming off your PC is unlikely to be worth it.

 

[Bassyhead]

Like Matthias99 said, the waste heat from your computer ain't worth trying to recover. It's probably worth a fraction of a cent per hour in terms of the electricity it took to produce it.

 

[Gibsons]

You can get some energy from that heat, but the amount of energy you can get is at least partly determined by the temperature difference of your heat source and the surrounding environment. In this.. uh, case... the difference really isn't all that great. Say 120F inside the case and 70F outside. So you'd get very very very small amounts of energy... I'd guess not enough to even turn a small fan.

 

[James Bond]

Just wondering

Thanks guys.

 

[CycloWizard]

One of my undergrad roommates did a report on this very topic and I thought the results were pretty interesting. Instead of trying to power his entire computer, he tried to power the CPU fan using a peltier. It turns out that you can generate enough power to turn the fan without much trouble. However, the kicker is that the peltier costs so much that it would take something like 10^18 years to pay for itself. Of course, now that the cost of electricity is increasing, maybe it would pay itself off in only 10^15...

 

[imported_Hamzter]

As already stated, it's impossible to power your own computer (unless it was a superconducting computer, which could be interesting, although still very unlikely that would work). If you wanted to collect the waste energy, it'll be a pretty feeble ammount. The maximum efficiency of a generator can be found from n = 1 - T(out)/T(in), where T(in) is the high temperature reservoir, and T(out) is the low temperature reservoir. If the case is at 40 degrees C, and the room temp is 20 degrees, you get a maximum efficiency of 15%, if your computer is giving off 200W of heat, you can recycle a MAXIMUM of 30W. That's only theoretical though, in practice it'll be much lower, and the machinery to collect that energy would be significantly more expensive than the money saved.