Gravity light
GRAVITY LIGHT | For developing countries
From gravity light founder | source: archilovers.com
“GravityLight is a revolutionary new approach to storing energy and creating illumination. It takes only 3 seconds to lift the weight which powers GravityLight, creating 30 minutes of light on its descent. For free.”
“How long does the GravityLight work for per lift?
The duration and power level/brightness are adjustable between just over 30 minutes and about 18 minutes (depending on what the bag is filled with). The light output on the video is generally at the higher power level.
How much light does GravityLight put out?
GravityLight is designed to be a replacement for a kerosene lamp. GravityLight’s output is better than a kerosene lamp.”
Source: http://www.indiegogo.com/projects/282006?c=home
Picture source: SocialCops