I don’t buy it. Hair dryers use a LOT of electricity. Plus, unless they have some sort of flywheel or intermediate battery, wouldn’t the power fluctuate if his speed alters?
.Leg Power replaces electricity in this Parisian beauty salon, where Madame has her hair dried despite the lack of coal-generated current. An ingenious beautician hires unemployed 6-day bicycle racers to peddle away on a bike, the back wheel of which is attached to a small generator! The current runs 6 driers.