I've been on WCG for almost 2 years and I gradually started becoming obsessed with points. So I bought an extra machine, then another and so on so until yesterday, I had 5 quads and 1 dual core Athlon running the project.

Unfortunately, my electric bill last month was just over $300. Since I use oil for heating and hot water is metered separately, there aren't a lot of suspects.

My marginal rate is 18cents/kwh. The big electricity hogs are fairly new and pretty efficient. However almost all of the machines are overclocked to some extent which also raises power consumption.

But even if I assume only 150watts at load (very unlikely), then for 6 machines, we get over 650 kwh/month or about $115.

Since my bill was for a little more than 1700 kwh, 650 would be around 1/3 of that.

Now if I'm wrong, and power usage is closer to 100watts on average, then it will be about 432kwh/month or $77.76. Not nearly as bad, but also not as likely IMHO.

If I were running the machines anyway, that would be different. Then we would just be talking about the marginal cost. But 4 of the 6 are dedicated solely (or virtually so) to just WCG.

I also have to consider the fact that marginal rates go up in the summer and that with central a/c, I get bumped into the third usage tier - which isn't that big of a deal, but it all adds up.

So I'm going to shut down 4 of the rigs until I get at least 2 new electric bills and compare them to last year. April will be the best test since I probably won't use much a/c.

I'd love to do wind or solar power and get free energy, but it's still just too darn expensive. If it turns out that I'm saving 2/3 of $115/month or more, I'll probably sell those rigs.

But my 2 main machines will continue to run and with the money from the selling the others, I might think seriously about upgrading to something with an i7 type flavor.

116.64 = 648 * .18
77.76 = 432 * .18