Yesterday we showed you one design firm's efforts to wring energy out of all sorts of doors, revolving, sliding and standard. Now take a look at the invention of Dr. Cedrick Ngalande, who wants to capture energy in a region that doesn't have as many doors--rural Africa.
Dr. Ngalande's Green Erg generator is designed to harness energy from the simple act of walking:
"This is basically a dynamo which is being driven as a result of friction between the ground and the blocks. The small yellowish blocks (these are covered by rubber in the real commercial product) rotate as you pull it. They are designed to rotate even on bumpy run even roads. We have tested it on moist lawns and have worked. It is very smooth so much that you basically don't feel any disturbance as you move along.
At normal walking speeds we have gotten more than 2 watts which is more than enough for running cell phones or radios. I envision that people will attach this to themselves and walk with it - or even attach it to an ox-cart, a skating board, bike, etc."