Actually, screw traveling -- if we could just drill a few hundred meters easily and cheaply, we could solve all our energy problems.

Temperatures roughly increase about 1 degree C for every hundred meters you go down. The difference could power a Stirling Engine (some of which are powered on differences of as little as .5 degrees C). It seems to me you could use a captive bolt pistol to get down just a few hundred meters, carrying a plastic tube which would have two chambers. The engine would pump the water and generate additional electricity. What do you guys think?