Source: http://gizmodo.com/sand-can-light-up-a-room-503861239
LED lightbulbs are already energy efficient, but they would be even better if they could emit light without connecting to the grid at all. Brooklyn-based designer Danielle Trofe is trying to make that happen.
Trofe created two designs for this month's Wanted Design 2013. Both are hourglasses that use the kinetic energy of falling sand to power a light bulb. One model is a sort of torch/flashlight-type situation, and the other is a flippable stool. It's a small step, but at least now you'll have enough light and a place to sit while you watch the environmental collapse of our planet. [Inhabitat]