Unlike other lighting products, the GravityLight doesn’t need to be plugged in or hooked up to a battery for power. Instead, it comes with an integrated generator that powers the light by harnessing gravitational forces.
Created by London-based Jim Reeves and Martin Reddiford, it’s a low-cost lighting solution that uses an elaborate system of gears and pulleys to produce energy. Just set the lamp up wherever you want it positioned, hang a weighted object on the integrated hook, and enjoy the illumination it provides.
A weight of around 25 pounds should be added onto the GravityLight’s hook to get things going, so a bag filled with books or rocks should be sufficient. Once you release the weight, it will then descend to the ground little by little, causing the drive sprocket to rotate slowly at a high torque. A polymer gear train turns this rotation into a high-speed, low-torque output that drives a DC generator to thousands of rotation per minute, generating enough energy to power the onboard LED. Depending on the height the weight is originally placed at, descent can take anywhere from 20 to 30 minutes, with the LEDs staying turned on the entire time. Once it switches off, simply raise the weight to repeat the process.
Granted, the LED it uses isn’t the brightest (it only uses a tenth of a watt of power), but for emergency lighting in places outside the power grid, this is an absolute godsend. Each GravityLight comes with two additional LEDs called Satlights, which can be plugged into the system to spread the light around the space.
An Indiegogo campaign is currently running for GravityLight. Pledges to reserve a unit starts at $70.