Genarate energy from heat

If you have a desktop PC with a 400watt power supply, you have to figure that it's normally idleing on about one-fourth of that and during intensive operations that involve disk drives and intense processing it can use say two-thirds of that. So you have 100 to 300 watts of energy turning mainly into heat (yes there's a little work and a little light).

Unfortunately, 200 watts doesn't cost very much create or to waste. All of the methods that I can think of to turn heat into energy--stirling engines, thermocouples, boilers are very expensive or don't recoup much energy or both. Yes, you can place thermocouples that power LED's. What is the use for these LEDs? Just to put on a light show? I'd rather save the money.

If you want to save power, laptops are far more efficient in every aspect. They don't waste much heat at all. Companies have designed desktops with laptop components so that they were efficient, but people that prefer a desktop (myself included) are ususally looking more for processing power/speed. Faster chips are seldom efficient.

Also, half of the year, heat isn't bad. My company doesn't even heat the engineering department--the computers keep the building quite warm--sometimes even the AC comes on in winter.

Any attempt to convert the ancillary heat generated by a source computer would impede its removal somewhat, especially if it is critical to remove the heat.Passive cooling can move a lot of the heat away though.

IMHO, one should endeavor to not convert so much electricity into heat to begin with.