10. You should open your gym. Advertise that this is what you are going to
do. Of course, what if only one person is bicycling at some time. Do the lights go out?
Sounds like the germ of an interesting enterprise. See what you can do with it.
Maybe to start, some of the equipment in your gym could be hooked up to a generator somehow, and you could give people a choice of whether to use the energy-generating equipment or the coin-operated public energy equipment.