Solar hot water

It turns out a stack of energy hits every square metre of the earth's surface every day. Especially in the bits where its daytime.

Pictured here, and using the sun for scale, is an impressive looking graph showing exactly how much that could be. One way to combat such a graph is by collecting solar energy.

Hot water represents a fair slice of power consumed by most people's homes, and as such, is a good place to start. The problem with buying a solar hot water system is all the work you have to do to earn all the money you need. If you make it yourself it still takes some work, but you learn some stuff along the way and save a stack of cash.

The ambient temperature of space is a nippy -270°C (there is no wind chill factor) but the average temperature here on earth is a balmy 14°C. Quite pleasant really in comparison.
All you have to do is figure out a way to pick some up, move it to somewhere else, and add it to what's already there. Do that a bit more and suddenly your bath goes from being potentially deadly to rather pleasant.

Basically there are great wads of energy lying around free for the taking. I'm going to have a crack at picking some up.