Using Gym Rats' Body Power to Generate Electricity

Carl Bialik from WSJ writes "A Hong Kong health club is hoping that a car battery, some StairMasters and dozens of gym rats can help ease the world's energy problems. It is just one of a wave of projects that are trying to tap the power of the human body, the Wall Street Journal reports. The article explains the impetus behind the project: 'The human power project at California Fitness was set in motion by Doug Woodring, a 41-year-old extreme-sports fanatic and renewable-energy entrepreneur, who pitched the experiment to the gym's management last May. "I've trained my whole life, and many megawatts have been wasted," says Mr. Woodring, who has worked out at the Hong Kong gym for years. "I wanted to do something with all that sweat."'"

Comments

Inefficient use of human body

[Reverse Gear]

The article doesn't hide this either, but there is really very little real energy to be won in this way, I don't really get what Mr. Woodring says about megawatts being wasted though, no human is able to generate that much electrical power, maybe he refers to megawatthours which he might be right about, but it would have been generated over the span of many years.

I think it would be more efficient if the people who go to the gym instead would just put on a pair of running shoes and would not have to exercise in a room that had not to be lit and heated for the purpose of them having a place to exercise.

I guess the best thing about this is that it might raise some people's awareness of how much energy different electrical devices use during the day and might help them remember to shut them off and think of energy efficiency when they buy new equipment.

The good thing about the way the human body works is not how much energy we use or generate, our biggest strength in this is the precise and versatile we can use our bodies and the energy we generate from the our food intake.
For example I bet you can save a lot more energy and pollution from exercising by getting wood for heating than you would ever be able to make by exercising a stair machine or spinning device.

Re:Inefficient use of human body

[Anonymous Coward]

Why are americans so ignorant and uneducated when it comes to CO2. It is as if you dont learn this stuff in compulsory highschool. What is it americans actually DO in high school? Bible studies or some shit like that? :)

When our bodies burn sugar we exhaust CO2, yes. But since this CO2 was originally taken from the air during the growth of the plant, there is no net addition of CO2 to the atmosphere. The food we eat is grown in our atmosphere; thus we have a CO2-circle. If this natural CO2-circle somehow was unstable and more CO2 was released than what was consumed we would not be living today. Think before you write.

This would be an environmetal benefit if we compare to generating the same energy by burning fossil fuel. Say coal. Burning coal is not part of the CO2 cycle - thus it adds CO2 to the atmosphere. The danger is NOT CO2; but from where the C in CO2 come frome. Why do you always get this wrong, its quite irritating.

Also I guessed the first reply to this post would correct you, but noo.

Re:Inefficient use of human body

[Eivind]

Possibly, but doubtful. As stated, if the exersize-bikes where in use for 10 hours/day, they'd pay back the investment in 82 years, but since they probably get replaced within 5 years anyway, that's never going to happen.

It's much easier to *save* energy than to *create* it.

Replacing 10 of the ligth-bulbs in the gym with modern low-energy ones would've had a larger effect on energy-savings, and would've costed less than the $15.000 this cost.

It's a gimmick, nothing more.

Re:Inefficient use of human body

[LarsWestergren]

maybe he refers to megawatthours which he might be right about, but it would have been generated over the span of many years.

For one person yes, but if you have hundred or thousands of customers per day pedalling/rowing/stairstepping, it adds upp quickly

I think it would be more efficient if the people who go to the gym instead would just put on a pair of running shoes and would not have to exercise in a room that had not to be lit and heated for the purpose of them having a place to exercise.

a) People in big cities rarely have good places outdoors to run. b) If it is winter and snowy, it can be difficult to excercise outside too. c) Some people prefer to build muscles over doing cardiovascular excercise. d) Heating and lighting a gym isn't more wasteful than heating and lightning any other room.

I guess the best thing about this is that it might raise some people's awareness of how much energy different electrical devices use during the day and might help them remember to shut them off and think of energy efficiency when they buy new equipment. The good thing about the way the human body works is not how much energy we use or generate, our biggest strength in this is the precise and versatile we can use our bodies and the energy we generate from the our food intake. For example I bet you can save a lot more energy and pollution from exercising by getting wood for heating than you would ever be able to make by exercising a stair machine or spinning device.

Now these points I agree with 100%. :)

Re:Inefficient use of human body

[Tim C]

I think it would be more efficient if the people who go to the gym instead would just put on a pair of running shoes and would not have to exercise in a room that had not to be lit and heated for the purpose of them having a place to exercise.

While that's true, running isn't ever going to replace gyms. Two immediate reasons are that running does little or nothing for building up muscle bulk, and it's a high impact exercise (as opposed to something like swimming or cycling, where you're not pounding the pavement the whole time).

Re:Inefficient use of human body

[Aladrin]

Maybe it's about efficiency. If they spare time, they might choose to do just that. For the rest of us (who have NO spare time) it's about getting the most efficient exercise in the time we have.

Re:Inefficient use of human body

[Eivind]

True. Nevertheless, for this application, even an order of magnitude reduction in price wouldn't be enough. Currently it takes 82 years for payback -- assuming 10 hour/day usage (which is excessive, very few machines are in practice used even half of this)

So, with an order of magnitude improvement, (i.e. $1500 not $15.000) in price, you'd still be looking at 8.2 years of 10 hour days for payback. (or on the order of 20 years or more for more typical gym-use) this for equipment that is typically replaced after aproximately 3-5 years.

Harvesting "human power" will never be able to do much for your energy-bills. It can make sense for other reasons though. For example, a handy that is powered by movement, and thus stays charged forever aslong as you're walking/moving would be a very practical thing to have for many people. I'd love this in my GPS too: I only bring it along when I go hiking in the mountains anyway, if my movements could somehow supply the (small; sub 1w) power-requirements it'd mean I could have it on all the time and never worry about running out of batteries again, rather than turning it on to log a certain point-of-interest only occasionally during the hike as I do today.

With low-enough energy-demands I could see this for for example remote-controls or wireless game-controllers too. Never having to replace batteries is a nice thing, more for practical reasons than for cost-reasons. (rechargable batteries aren't that expensive anyway)

Infantry also has need for gadgets. Many of them would benefit from being able to work indefinitely without access to recharging and/or new batteries. (nigth-vision, GPS, radio, led-torches, ...)

More like

[Zouden]

It is just one of a wave of projects that are trying to tap the power of the human body

I'd say it's just one of a wave of projects that are trying to tap the venture capital being thrown at "environmental-yet-supposedly-profitable" schemes.

Oh sure, make a joke at someone elses expense...

[Afecks]

Fat people get it the worst. No other group of people are so easily attacked and mocked. Most people wouldn't dare say "look how black that guy is!" for fear of being labeled a racist. However, very few of the same people would have any problem saying "look how fat that guy is!". Calling someone a nigger, faggot or fatass are all in the same group of insults. They are insults designed to hurt someone by mocking their differences. Yet somehow we all let that last one just slide by.

We accept each others differences when it comes to race, religion, sexuality but since being fat is "unhealthy" then it's unacceptable. I call bullshit on that. There are no special exceptions when it comes to bigotry.

But I'm not telling anyone what to do, just making an observation.

Poor Implementation

[necro81]

The article describes the system as siphoning off excess power from the generators already built into the equipment to run the exercise computers. It is like the dynamo on a bicycle - a parasitic power sink. They are only capturing a small fraction of the available power. The majority of the power the human inputs into the gym equipment still goes into waste heat production, same as the unmodified equipment.

A much better way to capture human power would be to scrap the power sink (the friction mechanism, for instance) and replace it with a real electrical generator, not just some dynamo rated for a couple of watts. With the proper power electronics, you can adjust the mechanical resistance that the human feels by adjusting the electrical power drawn from the generator. This would be similar to how regenerative braking works in hybrid cars. The braking action can be soft or hard, depending on the pedal input, and works by modulating the power drawn out of the generator and into the battery bank. Like a hybrid car, the mechanical resistance (i.e., traditional brakes) becomes almost superfluous.

This system would allow you to capture far more of the human power and convert it to electricity. With a well-chosen generator and well-designed power electronics, the conversion efficiency can be over 75%. For a human producting 100 W on a stationary bike (a decent workout), that would be 75 W of electricity.

This idea does, however, require a more substantial redesign or retrofit of the existing equipment, designed into the equipment and the gym from the beginning. As a result, I think it is unlikely to come about anytime soon. It would be a fun home project, however. Anyone know if Make Magazine has done something with this?