People Power: Getting a Feel for Joules & Watts

This week, we had a reader write in: Why has no one developed a battery that can be attached to a recumbent bike to gather energy when someone is pedaling? Thousands of hours of manual work is being wasted (not counting the health benefits) The short answer is "conservation of energy"--if you're putting work into charging a battery, it's going to make it harder to get where you're going by pedaling. However, some people have tried creating an electric bike with a motor and regenerative brakes, w...