The self-generating yo-yo energy gadget from Potenco, is a pull-cord device that could make energy available to many more pople.
To generate electricity, pull the cord. The 14 oz Pull-Cord Generator (PCG) generates a peak average power of about 20W. One minute of pulling generates enough power for one hour for a LED flashlight.
Thankfully it’s durable enough to be resistant to dust, sand and dropping it. Per Potenco, the PCG can power rechargeable batteries, house lighting, mobile phones, radios, GPS and notebooks.