It’s a tough ask. A bicycle generator will be 70% efficient, and a healthy amateur could do 100w over an hour of effort generating 70w. A treadmill would have a lot more friction, and a rowing machine gets nowhere near the power you can generate from your legs. A linear “foot press” exercise machine is not as efficient as the circular motion of cycling.
Power requirements of a gym might also include music systems, outside lighting. Heat/hot water could come from gas.
It can still be worth adding generators and wiring to exercise machines to offset energy consumption, including batteries to prevent peak TOU rates. But it is a tough ask to disconnect from grid, without solar.
If you get 15k hours and 1500kwh out of the machine, if electricity rates are 20c/kwh, that is $300 in savings. It’s not amazing, but maybe “there’s some appreciation value for members for the clean energy”
It’s a tough ask. A bicycle generator will be 70% efficient, and a healthy amateur could do 100w over an hour of effort generating 70w. A treadmill would have a lot more friction, and a rowing machine gets nowhere near the power you can generate from your legs. A linear “foot press” exercise machine is not as efficient as the circular motion of cycling.
Power requirements of a gym might also include music systems, outside lighting. Heat/hot water could come from gas.
It can still be worth adding generators and wiring to exercise machines to offset energy consumption, including batteries to prevent peak TOU rates. But it is a tough ask to disconnect from grid, without solar.
It seems like a lot of extra overhead for marginal benefit.
If you get 15k hours and 1500kwh out of the machine, if electricity rates are 20c/kwh, that is $300 in savings. It’s not amazing, but maybe “there’s some appreciation value for members for the clean energy”