New User, New Question: self generated power

Thank you for this forum, and thanks in advance for any answers. Question. What if you designed a new kind of gym in which you attached generators to nautilus, elliptical, rowing or similar machines so that you captured the small amount of energy in this process… like those lights they have on bicycles that are powered by the cyclist… and used that energy to power the lights, treadmills, etc? Is this possible? I don’t mean as an economic model or business model, but just theoretically. There is obviously energy in this process, when people work out on machines like this… and on a nautilus machine or stationary bicycle, this kind of thing, you can capture that, right? Well, what would it take to pipe that into a storage device of some kind on site at this gym? Is this possible? Thank you for any replies.


  • BB.BB. Super Moderators, Administrators Posts: 33,143 admin
    Re: New User, New Question: self generated power

    Possible yes. And versions have even been done (bicycles are popular).

    You can google around for bicycles and human power and find simple projects like this one.

    And, you can even store 80-95% of the generated energy in Lead Acid Storage Batteries for use later--either to power stand-a-lone equipment or even feed back into the grid (at least, that is doable---may not be legal per electric code).

    Then there is the practical issue... The "average" human can probably generate ~100-200 watts on a bicycle in a session. Assuming 30 minutes a session--that would be around 50-100 Watt*Hours or about $0.01 to $0.04 of electricity per session.

    Now--if you can keep the bicycle "running" 5 hours per day--that will give you about $0.05 to $0.20 of electricity per bicylce per day.

    Or, you can purchase single Evergreen Solar ES-A-200 200 Watt Solar Panel for $825 which will generate power for 5 hours per day, for 25-40+ years with zero maintenance.

    There is the whole issue of support equipment, permits, installation, inspection, etc... Very roughly, it will cost you around $10-$20 per Watt (solar panel, GT inverter, battery bank, 20 year maintenance etc.) for the system...

    So, a 200 watt bike system would cost, very roughly, $2,000 to $4,000 per "seat". And you would need to probably install around 15 bike setups (or per 200 watt solar panel) to justify the minimum charges.

    Obviously--the above is a very rough back of the envelope design and discussion of costs. The "real system" (if it can be legally done to code) may cost you more or less... But it does give you some ball-park numbers to play around with.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • TnAndyTnAndy Solar Expert Posts: 249 ✭✭
    Re: New User, New Question: self generated power

    For MANY thousands of dollars investment, you might get enough power to run a light in the manager's office.....might.....
  • stephendvstephendv Solar Expert Posts: 1,571 ✭✭
    Re: New User, New Question: self generated power

    There are already a few gyms like this in operation, just google for "Human powered gym". As the other posters have said, not really worth the investment from a pure efficiency point of view - but it would make an interesting marketing hook in communities that care enough about environmental concern.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: New User, New Question: self generated power

    i see nothing wrong with generating some power that way. it will, as pointed out, add a huge cost per watt of generation, but many of those exercise machines that cost many $ anyway could at least possibly serve a dual purpose. who knows as it may give more incentive to exercise more. it could be a small generator and a regulator for batteries or you can place a small gt inverter like the enphase as a possibility. it depends on how resourceful and creative you are in implementing such an adaptation.
  • sub3marathonmansub3marathonman Solar Expert Posts: 300 ✭✭✭
    Re: New User, New Question: self generated power
    TnAndy wrote: »
    For MANY thousands of dollars investment, you might get enough power to run a light in the manager's office.....might.....

    I guess nobody's watched Soylent Green? The movie was set in 2022 (had to look that up) where there were few natural resources left on earth. Edward G. Robinson had to pedal a bicycle setup to generate enough electricity to power a lightbulb. (It was Edward G. Robinson's last movie.)

    Also, after a bit more research, apparently the movie Soylent Green was the first mention of the term "Global Warming."
  • bentherebenthere Solar Expert Posts: 113 ✭✭✭
    Re: New User, New Question: self generated power

    I've read that the power required to keep a bicycle going 20mph is 60 watts. Often compared to the power to run one low-beam headlamp on a car. It takes a fit cyclist to average 20mph solo. That should give you a rough idea how much power a human can generate.
Sign In or Register to comment.