If you're really into prepping, no doubt you have batteries and a generator. Both are great, but what will you do if your batteries and fuel for the generator run out?
Portable Solar Power How-to
Fortunately, there's a power source that will never run out (or at least not for a few billion years). Not only can solar power help you save on your electric bill now, but it's a great resource to have when the power is out longer than your batteries and generator fuel lasts.
Check out this video to learn how to build a portable solar power system.