The green cube is a portable renewable energy device that harnesses solar, wind and mechanical energy and stores it in Li-ion cells. It has two small detachable wind turbines and a solar panel that can be kept in the device itself. In addition to this, it also has a hand-cranked generator at the back. It has a separate USB output for the solar panel, hand-cranked generator, and wind turbines. The best thing about this design is that even if there is a cloudy day outside, one can still charge their phone or attach their USB Bluetooth speakers or light an led lamp just by using the hand crank generator at the back of the device.

 

Complete Project Link: http://www.instructables.com/id/The-Green-Cube/