SETI@home vs. Bitcoin

I have an issue with bitcoin. Well, a few issues. It’s bad for the environment, it’s an unstable currency, blah blah, etc. Charles Stross covered most of my complaints. I have one in specific that really bugs me, though: All that computing power, and that carbon footprint, is just being applied to generating more bitcoin.
Well, duh, of course, what else would it be used for? Well, when I first heard about bitcoin, I didn’t quite get how it worked. I thought that the bitcoin mining process essentially loaned out your computer’s processing power to various networks that needed it, giving you bitcoin in exchange for that. I pretty quickly realized I was wrong, though, and that the mining process didn’t do anything but, well, mine. After a number of conversations and a good bit of thought, I’ve come up with an idea for a slightly more interesting and useful form of cryptocurrency: SETI@home Coin. (Note, not my original idea. I did come up with it on my own, but many others have come up with it separately before me. It happens.)