What would you see if you had only four hours to visit Paris?
OK, so you'd probably not be that dumb. And because you're not that dumb, you're probably also smart enough to research various power needs before embarking on a year-long (at least) journey. Well... you'd not be us then.
Four hour in Paris. I highly recommend not doing it that way. It's a lovely city and deserves more time. We, unfortunately, had no more to give.