If there's a separate incentive to keep the system on, then it doesn't function as a disincentive to cause build failures. If you're worried about keeping yourself honest (i.e. not turning the system off), then there could be an escrow service where you prepay and can't get that money back. After every build failure, the escrow contributes a small amount to the "bad" charity, then at the end of the year, the remaining funds get contributed to a "good" charity.