Maybe he means something like harnessing the static charge that might build up with the right kind of material. (think of when you walk on your carpet with your socks, and touch something metal - zot!)
I thought about maybe flexible solar panels, but what if they have to hide in a cave - give them a little crank to plug in somewhere and tell them to give it a couple of turns every two hours?

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It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D