Yep, solar water heating is a time-tested way to get energy from the sun and put it to use. A lot of the earliest solar power deployments (like Carter's White H

Yep, solar water heating is a time-tested way to get energy from the sun and put it to use. A lot of the earliest solar power deployments (like Carter's White House) were solar water heaters. There are even a few cheap off-the-shelf solar water heaters on Amazon these days (when I first researched the problem a few years ago, it was strictly a DIY project if you wanted panels small enough for an RV). Getting water to the roof is usually a difficult problem in an RV (requires breaching the roof without introducing leaks, and finding a path through the walls from the existing water heater to get there), but my current RV has an easier path than my previous one, so I might give it a go next time I've got a free weekend.