I did the SETI@home and Genome@home, as well as a couple of others years ago. I worked on G@H until it was completed, and I dropped SETI and other distributed computing solutions when my father started showing signs of Alzheimer's Disease. Folding@home has the ability to make a personal difference in our lives.
These programs for protein folding will not be a novel fade but will expand dramatically as we realize that some simulation problems cry out for lots of slower, cheap computers instead of a gigantic supercomputer.
You do not need to keep your system on 24/7 if you don't want to. Yes it gets more work completed but, as you noted, power isn't so cheap anymore.
So turn it off when you are finished with the computer and don't worry about it. The work units will still get completed in plenty of time to give credit for it and to help science progress. Plenty of folks only run their PS3 on weekends and they just fold then.
FWIW, the average computer running F@H will add between $3 and $10 per system over the course of a month, per DOE studies.
It’s a worthy cause. I fold on my laptop at work— my company pays for the power, heh, heh!
Sorry, I gave at the office. ;)