A non-profit called Empower Playgrounds has developed a way to harness the energy of kids playing in order to provide electricity to poor rural villages in Africa. The organization is making merry-go-rounds that have a clean tech twist -- onboard kinetic energy harvesters that store that energy in batteries for later use.
This idea is similar to the Soccket soccer ball by Uncharted Play that creates and stores electricity from being kicked around and played with. The stored electricity can then be used later for lighting, etc.
How much energy can a merry-go-round really provide? In an interview with Fast Company, founder Ben Markham says that a healthy 8- to 12-year-old generates about 150 watts of energy per hour whilst vigorously playing. All that energy is stored into battery packs which are then used to power advanced LED lanterns donated by Energizer. At schools in Ghana where Empower has provided equipment, kids split into lantern groups and study together at night where before they couldn't study past sunset. The lanterns last 50 hours on each charge.
According to Fast Company, "Empower Playground's equipment is affordable and effective. To install a system in a school costs about $10,000, which will supply 200 children a year electricity for at least five years. It breaks down to about $10 per year to give a child who spends half his or her life in the dark light to study by."
You can read more about Empower Play and their merry-go-round at their website.