Lamps, flashlights and lanterns frequently run on batteries or solar power, but the Green House GH-LED10WBW lantern only needs a drink of water with a dash of salt mixed in, and it’s good to go. It’s all thanks to its power source, a consumable rod that is filled with magnesium and carbon. Salty water facilitates the flow of current for up to 8 hours. The rod will need to be replaced every 120 hours.
Even better, it can also charge USB devices, although it can only output 4.5V so it can’t charge tablets and other power hungry gadgets. No word on its price, release date or availability though. I wonder if you can power it with tears. Or urine.