What's a watt? The real meaning of electrical power needs to be accessible to all of us, not just the scientifically minded.
A bicycle powered electrical generator can help to deliver a better understanding of what power really means for all of us. Switching on a light or an air conditioner is simple enough for a one year old, but when you have to pedal to power the device then you can feel the meaning of power. Inspired by the BBC TV programme Bang Goes the Theory broadcast in late 2009, we rigged a bicycle to a generator that powers either 150 Watts worth of regular tungsten filament lights or 25 Watts worth of compact fluorescent lamp. You can feel the difference on your legs.