Here are two ideas that should be put together: a windmill made from recycled parts and humpback whale fins.
Entrepreneur, William Kamkwamba, lived in a house without electricity or lights, but what he did have was a vision and the ability to read. At age 15, he went to the library and picked up a book about windmills. After finding all the parts he needed including wire, a battery, a bike dynamo, an old bike frame, a truck motor fan, a few gum trees, and some plastic to build the blades, he got to work with the goal of lighting 3 or 4 light bulbs in his parents home. After a few years of trial and error and continual improvements, he achieved his goal. He eventually made his windmill taller and added a more powerful generator from a treadmill, and it now powers ten lights. He has plans to make the windmill even more powerful to pump water from a well and irrigate his fields. Here's a video:
Dr. Frank E Fish, president of WhalePower, has recently patented a new turbine blade inspired by humpback whale flippers. Humpback whale flippers have bumps on the leading edge, which reduce drag, and improve agility using what he calls "tubercle effect". The first prototype turbine fins showed reduced drag, were quieter and more efficient, and operated at lower speeds. The tubercle blades overcame many of the "limitations" that were once considered unavoidable constraints by fluid dynamics scientists.
Speaking of bio-inspired engineering, here's a picture of shark skin using a scanning electron microscope (SEM). I've used an SEM before to image some bacteria I found living on my hands. The shark skin looks quite tough to produce synthetically, but if you could I bet you'd see the winners of the swimming events at the next Olympics wearing suits made out of it. Image from National Geographic. Another bio-inspired invention was Velcro, invented by a Swiss engineer in 1941. The idea came to him after a day of hunting with his dog, when he noticed all the burrs in the dog's coat.