Clean Power

Published on December 6th, 2013 | by Guest Contributor


What’s The Value In An Energy-Producing Gym?

December 6th, 2013 by  

Originally published on Climate Progress
by Emily Atkin


Image Credit: Shutterstock

There is a gym in England where crazy workouts do more than just power muscles. They also power the building.

The 42 crosstrainers, bikes, and treadmills at the Cadbury House Club in Congresbury can convert human energy generated during a workout to electricity which eventually powers the machine, Green Futures Magazine reports. The surplus energy that is not used to power the machine is channeled into the gym’s own power supply via “brushless motor” technology, which reportedly reduces energy consumption by 30 percent.

The club installed the ARTIS Technogym machines — at a cumulative cost of £600,000, or $981,120 — in order to combat rising energy costs. Jason Eaton, the general manager of the gym, said in a statement that the technology is “reducing the level of energy needed to power the club, which is great for the environment.”

The question has been raised as to whether the innovative idea will bring meaningful energy efficiency benefits. Dr. Tzern Toh, an electrical engineering researcher at Imperial College in London, told Green Futures that the high cost of installing the equipment may outweigh the benefits. “The price of electricity is many times less than the cost of the equipment and it may take months or years of electricity savings to recoup the investment,” he said.

But “months or years” to recoup on spending does not seem like such a long time compared to the alternative, which is to wait while energy costs soarRecent European research has shown that energy prices there are rising at up to eight times the rate of earnings, with the area’s six biggest suppliers having increased their prices by 37 percent since October 2010. During that same period, average household earnings only rose 4 percent.

According to Business Green, each of the ARTIS machines is capable of generating 100 watts of electricity, meaning each could power an 18-inch standing fan at the highest setting, a desktop computer, a large stereo system, or two laptop computers. However, the energy that is not being used by the machines themselves is not currently metered, so it is too soon to tell just how much energy is being saved by the company. Green Futures reports that the gym does plan to eventually install tracking software that would read energy input and output levels.

Though Cadbury House Club’s machines are based in Europe, similar innovations are happening in the United States as well. In January, Earth Techling reported on a company called SportsArt Fitness, a company that makes workout machines that are designed to pipe human-generated power to the grid. The “Green Room” gym at Tennessee Tech University currently uses the gear, which can reportedly convert 75 percent of the power generated into usable energy. A system of 10 machines could, depending on how hard people are working out, produce up to 2 kilowatt-hours of electricity in an hour, SportsArt said.

“Some people wonder whether these systems will pay off financially for a gym, given the investment it takes to install them,” Earth Techling’s report said. “But whether they do or not might be missing the point: Each kilowatt-hour generated means one less kilowatt coming from a power plant (likely to be powered by fossil-fuels).”

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  • Bob_Wallace

    Whenever I read about generating power with human muscles I’m reminding of Oscar Wilde’s imprisonment….

    “Hard labor” in an English prison was no euphemism. Every prisoner was expected to walk six hours a day on a treadmill in 29-minute increments with five-minute breaks. The distance to be covered was the equivalent of a 6,000-foot incline. Taken from the Old Bailey to Newgate Prison, Wilde had his belongings taken from him and was outfitted with gray prison togs with their distinctive black arrows pattern.

    Shortly after being read the rules of the prison system utter silence at all times Wilde was taken to his cell and fed a typical meal of watery porridge and a slice of bread.

    From Newgate he was taken to Pentonville Prison where he was placed on the treadmill. At night he was returned to his cell, where he slept on a wooden plank without mattress.

    Diet at Pentonville consisted of cocoa and bread for breakfast, soup or sliced meat for dinner, and suet and potatoes for tea. Exercise consisted of walking in a circle single-file silently for one hour a day. He was required to attend chapel every morning and twice on Sundays. Visitors were allowed once every three months for 20 minutes.

    Physical contact was out of the question, as were books, paper and pen.

    “Already Wilde has grown much thinner,” wrote a contemporary newspaper. “He has great difficulty in getting to sleep, and from time to time he loudly bemoans the bitterness of his fate.”

    Six hours a day on the treadmill and then you get to walk for an hour in order to get some exercise. I’d be bitchin’ too….

  • Wayne Williamson

    I can’t help but thinking of a Fred Flintstones bus where all the passengers are peddling away…not practical but still funny to think about….

    • Bob_Wallace

      We have that sort of transportation around here.

  • Manitou820

    If the same money had been spent on efficiency improvements and/or roof top solar, would more energy have been saved? I’ve got to imagine this is not the most cost effective way to save energy.

    • Kyle Field

      It may not be the most efficient or cost effective…but it’s another potentially easy sustainable win. Depending on how the financials work out, this could also be a neat supplement to a residence…in fact my wife just got off our treadmill as I’m sure many others just did as part of their normal routine. A few watts saved or generated per day…baby steps 🙂

      • Peter Gray

        Not to be facetious or snide, but in what sense can something be inefficient and cost-ineffective, but still an “easy win”? If the equipment costs many times more than the energy it can produce, that’s a sign that more resources (including energy) went into it than it will ever save. Not a win at all.
        Perhaps the biggest benefit of this will be to demonstrate to those who don’t already know it, how many times more energy we each consume than we can physically produce.
        Take your home example. A strong athlete such as a long-distance bike racer can put out 100-200 watts all day long. Note that 100W is the upper limit for one set of machines described, 200W for the other.
        Few of us average as much as 1 hour at 100 watts, every day of the year, on exercise equipment. If every member of a family of 3 does that, they’ll make 0.3 kwh/day, worth $0.06 at $0.20/kwh (the extreme high end of U.S. continental retail prices – average is $0.125). That’s $22/year, and it’s about 1% of typical U.S. household electricity consumption.
        In the unlikely case that your exercise-to-power equipment costs only $400, you’ll break even in 18 years at 0 interest. With 2 people pedaling: 27 years.
        For comparison, a single 80-watt PV panel with a capacity factor of 16% will make the same energy, at a small fraction of the cost. Since whole-system costs of solar are dropping toward $1/watt, an additional PV panel must be about there already ($80/panel). Doubling that for the whole system, gives $160 to replace that well-used home exercise system with solar.
        The UK gym spent $23k for each of its 100W units. if they’re in full max operation 10 hrs/day, 365 days/yr, they’ll save $73/yr, for a 315-year payback time at 0% financing. Maybe a nice marketing angle, but not a good place to look for renewable energy. As someone else noted, the article gives no clue about how much of the total cost is for the power part, but if the additional cost of each generator-equipped treadmill were only $1k out of $23k, payback is 14 years, still longer than the equivalent PV.

        • Kyle Field

          I appreciate the comment…I’ll explain my comment. If viewed as a proof of concept of the technology, the price of these particular units doesnt matter. It doesnt matter because the first few are always the most expensive – just think about how much solar panels were 30 years ago vs today. We are where we are now because of those early units and early adopters who were not concerned with the efficiency and probably will not pay out in the long run (or as you noted, may even take more energy to produce than they can ever create).

          In the near term, these installations and models are generating news stories (such as this one) that raise awareness to the public about sustainability. That’s a win.

          Looking farther down the line, these units will become more cost effective to produce and the power generating add ons will likely be negligible on top of already expensive exercise equipment. In 20 years, this may allow gyms to spend the same amount on equipment but have it last longer and be power neutral.

          More than the payout, I like the awareness that these raise. It’s a fun way for the average shmoe to engage in a more sustainable life and increasing awareness / spreading the word is one of our more difficult challenges..

          • Peter Gray

            Thanks for the nice reply, Kyle. Just a couple quick points.
            There’s nothing new or high-tech or very novel about this idea. People have been making generators and alternators of all sizes for many decades, and the tech is very well understood and worked out. There’s almost no room left for efficiency gains or cost reductions.

            People have hooked generators to pedals for many decades as well, to show how hard it is to light up a 100W bulb, for example. The reason we don’t bother generating power with humans is not that nobody thought of it before or that the technology didn’t exist. It’s because we’re physically too weak for it to be worth the trouble. Horses are far stronger, better at extracting energy from cheap grass, and willing to put in long hours. But as far as I know, horses aren’t considered a serious energy resource in the modern world.

            I get your point on raising awareness about sustainability, but the kind of awareness also matters. I see too many who recycle their cans and bottles, drive a Prius everywhere they go, and figure they’ve done their part for the Earth. Even after they erase a couple years of those good intentions by flying to Europe or Thailand for vacation – or to the vanishing Arctic for an Ecotour. That could be called a loss.

            I think many people would happily get the wrong impression that they’re doing their part by burning several liters of fuel driving across town to the Ecogym, where their pedaling recovers the equivalent of a couple spoonfuls. That would be a distraction and a loss.

            Yes, it’s hard to get people’s attention, understanding, and support. That’s because most “average shmoes” have limited cognitive bandwidth for this sort of issue. Why waste this scarce resource on things that don’t really count?

          • Kyle Field

            Good point and perspective. Given the solid points you made and I agree that just about energy generation produced by such equipment is likely not worth doing but could still serve as the proverbial shoe in the door for other real sustainability initiatives such as advertising residential solar, LEED building improvements/construction standards, plug in electrics, etc that many consumers are making real impacts with.

          • Peter Gray

            Good discussion, Kyle, and at this point we’re both speculating. I can’t begin to prove what the side effects will be from getting people interested.
            My concern still is that if we get their interest using something trivial or misleading in the big picture, that can waste an opportunity. Many are likely to believe that they’ve done their part, with something that can never make a real difference, or, when they look deeper and discover how pointless it is, they could conclude that nothing else will matter either, including solar, wind, etc.. Look around and see if you can say this hasn’t happened already! If we even imply that pedal power should be taken seriously, both of those bad outcomes seem likely.
            If we’re honest, we would point out upfront that if everyone on Earth (including babies and octogenarians) put full effort into a pedal generator for an hour every day (and the system ran at 100% efficiency), they could displace a whopping 0.2% of our fossil fuel consumption. Wouldn’t the natural reply be “Why are you even bothering me by mentioning it?”

  • Matt

    You should look at the total cost of the machine, but its cost – cost of same machine that doesn’t generate power. Is it $5000 verse $4900 or $2500. And the saving should include the NRG used to run the machine, since with standard machine it would be plugged into the wall. Then you can compare that to so changing the lights to LEDs.

    • Kyle Field

      Exactly. This makes so much sense and looks pretty compelling at least given the output numbers – generating 2kwh from 10 machines in 1 hour is significant.

    • Michael Bucari

      Except the gym presumably already had machines that didn’t generate electricity, so they’re replacing their perfectly good existing machines. Thus, the full cost is what counts. You could argue that machines wear out, so they’d need to be replaced anyway and you’re just replacing them early. If you’ve have a $3000 bicycle for 5 years, and it’s lifespan is 10 years, then the cost of replacing it today vs. in 5 years is $1500. So if you replaced your regular $3000 bicycles with a $5000 electricity generating bicycle today, the real cost is $3500. That’s only if the new bicycle also has a 10 year lifespan. If the lifespan of the generating bicycle is shorter than the standard bicycle (which is likely, given the added electronics), then the cost is even higher.

      Assuming $0.10 per kWh (a high-end estimate), and 2kWh / day from all 10 bicycles (best case from the article), the bicycles will generate 730 kWh over 1 year, totaling $73 ($7.30 per bicycle).

      That hardly makes up the difference.

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