Cleantech Powers the Developing World

Today’s LEDs are approximately 250 times more efficient (250 times more lumens per Watt) than those that first lighted Broadway in the late 19th Century. This has brought about some marvelous advantages, not only in terms of reduced power consumption, but also in enabling the development of conveniences that couldn’t have existed before this time.

Check out these lamps, powered by a modest amount of human strength, used to lift a weight against the force of gravity that is then allowed to fall slowly down towards the earth, converting its potential energy into mechanical, and then into electrical energy.  Though this is meaningless in the developed world, in countries that have no rural electrification it means the difference between light and darkness, enabling, for example, school children to read at night.