This reminds me of an old (misleading) graphic in Wired magazine suggesting that people on treadmills could be significantly reducing their electricity bills.
Olympic track cycling medallist powers toasting a slice of bread, which takes everything he's got and leaves him exhausted: https://youtu.be/S4O5voOCqAQ
That reminds me of a thread I saw on an Internet forum a few years ago about some guy suggesting powering his fridge with a bicycle during a power outage. Turns out this is an extremely complicated problem which is probably best solved by ignoring it.
I bet you would get better results directly spinning the compressor via a flywheel rather than trying to generate the electricity to run the refrigerator.
Yeah, toasters and microwaves take a ton of energy, 800-1000W.
Things like laptops and some desktops could be easily powered by bicycle, though. I managed 220W for 30 mins, and could probably idle 50-75W for hours, which is more than enough for multiple laptops.
Which is a very short lived behaviour change. Our smart display went missing during a house move, and hasn't been compatible with most of the energy suppliers we've had since moving in.
It was probably the worst energy scheme they could have spent the estimated £16bn on. That much in insulation would have slashed domestic heating costs, but as ever that's a much less sexy project.
I've often wondered if it would be viable to run a gym where all of the equipment is designed to harness customers' energy to help power the building. I suspect it wouldn't make enough of a difference to be worth it but have never seen anyone run the numbers.
Let's say a person outputs 500W and we can somehow capture all of it. That would be 10cents worth of electricity in an hour.
Note that these are very generous estimates, but it does demonstrate how silly the idea of trying to generate electricity by capturing exercise output is (in a purely economic sense).
500W is an extremely high number as well. Pro cyclists can reach up to 400 Watt in short bursts, untrained people typically can't maintain more than 100-150W for long. We really use quite a lot of energy when measured in how many humans it would take to provide that much energy "manually".
While it's true that the power of a human is not much (certainly not enough to power a house), but we have a lot of energy. Most of us carries at least 1 kg (~2 lbs) fat, which contains ~37 MJ of energy. For comparison, a stick of dynamite has ~1 MJ of energy.
> Pro cyclists can reach up to 400 Watt in short bursts
I heard pro cyclists can reach up to 2kW. I managed to make 500W on a rowing machine for 5 minutes, but I'm a couch potato. I believe 400W is a normal rate for cyclists. When you are sitting, your body already produces about 100W of heat.
So cyclists measure their capability in terms of FTP - essentially what power output they can maintain at full throttle for an hour.
This hugely depends on body weight / gender / training levels etc., body weight being a big deal since that’s what you’re transporting. So the other way folks measure output is W/kg of body weight.
A beginner adult male will be in the 100-200W zone, around 0.5-1.5 W/Kg. Usually anyone can train themselves into the 200-300 (3-4 W/Kg) zone which is the recreational pace - the groups of cyclists you see on the road. Beyond 300 ftp (150lb body weight) (4-5 W/kg) you’re reaching race pace. The ones you see on screen have upwards of 5-6 W/Kg FTP output. They obviously have other constraints around putting this output at the end of a 200km ride for 20 mins etc as well, which makes it extra hard.
Finally we come to the KW numbers - all these folks have two kinds of muscles (fast twitch and slow twitch). The sprinters are saddled with a higher proportion of the kind of fibers that can allow huge spurts of power - they put out about 1000-1500W for about 5-10s. These are probably what you’re thinking of. This is pretty much an end of ride (or a sprint section) empty your tanks effort.
Semi related tidbit: track cyclists are a middle kind of beasts here: they put 600-1000W for a couple of minutes but don’t have to worry about riding 200kms to get there.
Yes, and the Wired graphic was particularly misleading in that it showed, as I recall, multiple dollar amounts accumulating on per-session treadmill displays.
On the other hand, it is possible to imagine lifestyles enhanced by various 10W contributions. 10W for heated clothing. 10W for a laptop. 10W average to power a several km electric bicycle or Aptera-size commute. And so on.
How are you proposing we produce 10W to heat clothes? we produce around 80W just by sitting idle, just wear insulating clothes!
How do you produce 10W to power an electric bike? 10W is a laughable amount of power, just get rid of the electrics and pedal a bit.
10W is barely enough to charge a phone these days. Anything that gets moderately hot while in use is consuming more than 10W.
In their defense this could be seen as a type of gamification. Ultimately you can put any dollar amount on a kWh of electricity. It's the kWh generated that matters.
The Grand Tour has tried to answer that question. I thought the turnstiles idea was really good, especially if you place them in a building with heavy traffic. Though probably not really cost effective.
As a quasi sidenote, most gyms already implement this on a smaller scale on their elliptical and spinning machines as they're usually self powered and you can regulate the resistance the machine offers, which I assume must increase or decrease the number of magnets around the flywheel.
A dude did that, it didn't last long, but I'm still thinking about opening one. Just to avoid the double madness of powering lights and devices so people spend energy in the air :)
Even if you don't generate much, at least your biomechanical efforts are used somewhere.