I have to admit, conceptually this is very cool. Heck, I’d definitely be more inclined to get on a treadmill or elliptical trainer if I knew it was hooked up to my house backup batteries and could save me money on my electric bill. Maybe the motivation I need to exercise more (and save money!)?
This would be something constructive and practical to do to lose weight and save on an electric bill.
Just as there are Internet Cafes, it is possible, though it may be more science fiction, to one day have Kilowatt Kafes where you receive credits on your energy bill for working out at a place that sells the generated electricity but is also an exercise gym.