Some island countries experience daily outages of power, actually. It winds up being pretty easy to work around when you've planned to expect it (this includes things like backup power sources and so forth).
Even better, if the available power is low, just run things slower. Does web browsing really need all .8KW my desktop can drain out of the wall?
I have no idea what the entire setup uses when I'm web surfing, but the spare bedroom I'm in gets noticeably warmer. Would it kill me for the system to just spin down a little and make me wait and extra 2 or 3 seconds for a page to load?