Wow I have discovered something truly amazing. I for one never knew that thermo electric coupling existed, having never been a big science geek. But I recently discovered this awesome product. The PowerPot
The picture shows the pot sitting on top of my stove. It is filled with cold water, and the temperature differential between the cooler top inside the pot & the heated under side creates electricity!
As you can see, a wire comes out of the pot at the handle & it is powering a led light. It can also charge a phone or battery pack.
So with my stove on all night I can charge my (few) gadgets even on rainy nights.
The permutations seem endless & after a couple of hours spent googling the tech I am tempted to build some more charging systems - after all the thermo electric couplings cost as little as £3 on Amazon.. So we shall see what the future holds...