That's an awful lot of money, but not much when compared to other wastes (as 
Ray has shown).
Since I was curious about how much running my two computers at home 24/7/365 costs, I came up with this method for calculation. With minimal modification, you can use it to see how much your systems cost to run.
First, grab an electric bill and calculate what they charge you in dollars / KWH. (in my case, US$0.0742371)
Now, calculate the energy usage of your computers:
System: 100 watts (average per rig) * number of rigs (2) = 200 watts * (365.25 * 24 = 8,766 hours per year)  = 1,753,200 watt-hours
Monitor: (100 * number of hours run per day): 100*2 for one computer + 100*6 for the other = 800 watt-hours * 365.25 = 292,200 watt-hours
1,753,200 + 292,200 = 2,045,400 watt hours
2,045,400 / 1,000 = 2,045.4 kwatt-hours
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2,045.4 kwh * US$0.0742371  = US$151.85 (cost per year)
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Don?t show my parents this thread. 
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Edit: Titanmiller, I feel sorry for you with the situation with your parents and the computer. 
If you think your parents would be ok with the idea, explain to them the concept of DC. My parents were quite cool with it once I explained what Folding@Home is and what it does (maybe it helps that they have relatives with diseases that this project is trying to help understand).
If you think they wouldn't appreciate the idea of searching for ET, explain to them that SETI looks for astronomical stuff (Quasars - sp? - and whatever other things it is looking for), but don't mention what the acronym means. 
