How much power is used by distributed computing?

olddoc writes: I used to run Seti@home and Folding at Home. It was advertised as donating "unused" computer cycles. My computers now idle at 175w and run at 225w under load (without GPU load) I much prefer to put them in standby, but if I run these distributed computation programs instead of idling, I use an extra 50w. After 20 hours I can generate 1 work unit and use up 1 Kilowatt hour. For every 100 units I "donate" I've spent at least $10 in electricity; much more if I assume the computer would be in a 5 watt standby state 1/2 the time. I wonder if anyone has estimated the number of Megawatt hours Seti@home has used. It would be interesting to look at the amount of coal burned and CO2 released for US based contributers. French units are mostly nuclear powered and Icelandic would be hydroelectric and geothermal. My point is that this research consumes an awful lot of electricity.