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Very interesting to know roughly how much energy one can create doing this! Being part of the current trend of people riding at home on Wahoo Kickrs/Zwift and o

Very interesting to know roughly how much energy one can create doing this! Being part of the current trend of people riding at home on Wahoo Kickrs/Zwift and other turbo trainers, I do feel like that energy could be put to use somehow! Even if it were just to power a fan to cool myself down whilst riding, it would be nice to think the energy was being put to good use!

rzzzt 6y ago
700W continuous output for a few minutes exerted by a professional: https://youtu.be/S4O5voOCqAQ https://youtu.be/S4O5voOCqAQ (For mere mortals, it will be indeed closer to 100W.)
hn_throwaway_99 6y ago
I think once you do the math, and realize how incredibly little power a human can generate compared to modern electricity, you realize it's not really worth it. Literally forgetting to turn the light off in your bathroom twice a month would probably waste more power than a super-committed, hour-every-day stationary-bike-using person would generate. I don't mind these kinds of "solutions", but I do object when they go in the "make me feel guiltless about everything else I do because I hooked my bike up to a generator" bucket.
- LeifCarrotson 6y ago
  Agreed, but my son's crank flashlight is a great teaching tool and it never runs out of batteries!
- Zigurd 6y ago
  If you get above 400w, consider turning pro. Even though it won't run your refrigerator, I would have been pleased to be able to plug an external mobile device battery into a smart trainer during a recent power outage so i could continue to work on a book manuscript while power was out.
  - miahi 6y ago
    I don't think you can have a 400W bike FTP without already being a pro.
    - _Wintermute 6y ago
      There might be a handful of time trialists here in the UK with day jobs that could do that, but yeah no one is doing that without dedicating a huge part of their life to training.
  - rjsw 6y ago
    The winner of the Giro d'Italia stage today was doing nearly 600W for just over 17 minutes.
- dbrueck 6y ago
  But, but, but... you're ruining the movie "The Matrix"! ;-)
  - rienbdj 6y ago
    I wish The Matrix had humans in virtual reality cages because the AI had a mandate to keep them alive and well, and this was simply the most efficient mechanism for doing this. This would have made the resistance far more ambiguous as they would actually be fighting for freedom but against the well-being of humanity.
    - gruez 6y ago
      >I wish The Matrix had humans in virtual reality cages because the AI had a mandate to keep them alive and well Humans have finite lifespans, right? So all the AI has to do "relieve" itself of the burden of keeping humans alive would be to not let them reproduce. This would be pretty easy considering that it's pretty hard for people to spontaneously become pregnant while hooked up to those pods.
  - frutiger 6y ago
    Apparently the original story had the AI use the network of human brains as a giant neural network. As the story goes, the movie executives thought this would be too difficult for most people to understand, so they switched it out and used the thermodynamically unviable power source motive instead.
- WJW 6y ago
  Just as a quick example: Bringing a pot with 1 litre of regular room temperature water to boiling temperature takes about 0.1 kWh. A regular person produces about 100W during strenuous but still aerobic exercise so you'd need about an hour of cycling to generate enough energy. This doesn't include heating the pot itself btw.
  - angrysaki 6y ago
    Not disagreeing, but just wanted to point out that if the goal was to generate heat then humans could potentially be more efficient because of internal efficiency. The ballpark number I often see is 25% efficiency, so if you were able to somehow capture the waste heat they'd be able to heat up the water 3x as fast.
    - fastball 6y ago
      Fair point, though that is arguably the only situation involving electricity (besides heating the room itself which doesn't involve heat capture) in which you're actually trying to generate heat.
    - WJW 6y ago
      This would probably work better when heating up rooms rather than water. The benefit of using electricity as an intermediate form of power is that it becomes possible to heat water up to boiling temperature. Exercising humans never reach boiling temperature no matter how hard they try.
- csunbird 6y ago
  When you think about it, humans are really energy efficient at moving their limbs.
- Xylakant 6y ago
  You’re correct on the side of power generation, it’s a tiny amount. On the other side, we have come a long long way when it comes to efficiently using power. The combined power usage of my bathrooms lights is probably less than 60W. The largest MacBook uses less than a moderately trained human can produce. On average, fridges need paltry amounts, compared to what they needed a decade ago. Certainly, running a vacuum or boiling water won’t work with human power generation, but if you want that as a backup, you probably can fall back to a broom and use a gas/multifuel cooker in the meantime.
- TylerE 6y ago
  More importantly, I bet your hour a day user never comes close to the energy nessesary to build the bike and associates electronics in the first place
- dheera 6y ago
  Not only that, but human power is incredibly inefficient, especially if the food you are converting into that power is not plant-based. It's significantly better if you eat plant-based, but nowhere near a bunch of solar panels covering the same area that the plants did.
- Panino 6y ago
  > I think once you do the math > Literally forgetting to turn the light off in your bathroom twice a month 8h * 5W * 2 = 80Wh per month (Unless you're talking about using incandescent light bulbs, which would be like using a 4mpg vehicle in a discussion about average vehicle efficiency. Personally I think a 3W LED is better than a 5W, but I know most people disagree.) Our main bathroom light draws, I'd guess, 0.1W. It shows up as 0.0 with a kill-a-watt so I don't really know. And it's only used for about half an hour a day at most. > a super-committed, hour-every-day stationary-bike-using person 60W * 1 * 30 = 1800Wh per month So no, forgetting to turn a light bulb off for an entire night, twice a month, does not waste more electricity than that gained by a cyclist who is capturing their electricity. I think it's a great hack to turn this machine into an electrical generator.
  - hn_throwaway_99 6y ago
    Come on, this is "missing the forest for the trees" pedantics. I think you will find that the average bathroom in the US uses way above 5W. Regardless, it's just an example. The DoE says the average US residential customer uses 909 kilowatt hours per month. Using your math of a committed cyclist that generates 1.8 kwh per month, you're still looking at under .2% of energy replacement. Which, again, even the smallest efficiency improvements in a house would completely dwarf what a human could produce.
    - Scoundreller 6y ago
      I really think room lights are approaching 5W/bulb. I have a 3x5w bulb setup and keep 2 unscrewed just because it’s too bright when I have to go in at night. Incandescents are a hard sell when LED bulbs are $1-$2 and pretty reliable.
    - Panino 6y ago
      I can only respond to your words. If you don't like my choice of bulb, then do your own math and show it like I did. See what watt bulb (not bulbs plural, or moving the goalposts even further, an entire bathroom) it takes for your assertion to be true. Actually I'll just do that myself because it's easy. Now, we already discussed generating 1800Wh per month using this bike. So: 1800 / (8 * 2) = 112.5 Or in other words: 112.5W * 8h * 2 = 1800Wh So you'd need to run a 112.5W light bulb for 8 hours per night, twice per month, just to equal the amount of electricity produced by the article author. Although you said that leaving the light on wasted more, so, let's just go with a 113W bulb. I'm old enough to remember 100W incandescent light bulbs, but even then, they were rarely bought and used because that's an insane amount of electricity for indoor lighting. Now where I live I can't even buy incandescent bulbs because they're not for sale. For 112.5W to be average, there would need to be millions of Americans using stadium lighting just to take a shit. I think you should take a step back and reflect on why you're so quick to attack someone for doing a cool hack (this is Hacker News) that reduces their electrical usage (in the time of climate change).
- colechristensen 6y ago
  A single square meter solar panel which costs on the order of $100 will outproduce a human. If you're camping or in a power outage and want to charge your phone or some led lights, sure, a bike charger makes sense, but you'll never be net positive with the energy you create vs. the energy needed to produce the generator.
  - ezzaf 6y ago
    Solar panels only outperform a human when the sun is shining. From the article: "But what if skies remained gray for many days in a row? Rather than trying to purchase enough battery storage to cover all reasonable eventualities, I decided that my backup source of electricity needed a backup itself, one that I could use to charge that battery during times when my photovoltaic panels won’t function" As a primary source of energy a cycle generator doesn't make a lot of sense. But as an on demand source to cover occasional periods of low solar generation it's a great hack.
- ForHackernews 6y ago
  It's even crazier if you start comparing the energy used for training massive AI models vs. the paltry wattage required to keep a human brain operating.
layoutIfNeeded 6y ago
https://en.m.wikipedia.org/wiki/Fifteen_Million_Merits https://en.m.wikipedia.org/wiki/Fifteen_Million_Merits

rzzzt 6y ago

700W continuous output for a few minutes exerted by a professional: https://youtu.be/S4O5voOCqAQ https://youtu.be/S4O5voOCqAQ (For mere mortals, it will be indeed closer to 100W.)

hn_throwaway_99 6y ago

I think once you do the math, and realize how incredibly little power a human can generate compared to modern electricity, you realize it's not really worth it. Literally forgetting to turn the light off in your bathroom twice a month would probably waste more power than a super-committed, hour-every-day stationary-bike-using person would generate. I don't mind these kinds of "solutions", but I do object when they go in the "make me feel guiltless about everything else I do because I hooked my bike up to a generator" bucket.

LeifCarrotson 6y ago
Agreed, but my son's crank flashlight is a great teaching tool and it never runs out of batteries!
Zigurd 6y ago
If you get above 400w, consider turning pro. Even though it won't run your refrigerator, I would have been pleased to be able to plug an external mobile device battery into a smart trainer during a recent power outage so i could continue to work on a book manuscript while power was out.
- miahi 6y ago
  I don't think you can have a 400W bike FTP without already being a pro.
  - _Wintermute 6y ago
    There might be a handful of time trialists here in the UK with day jobs that could do that, but yeah no one is doing that without dedicating a huge part of their life to training.
- rjsw 6y ago
  The winner of the Giro d'Italia stage today was doing nearly 600W for just over 17 minutes.
dbrueck 6y ago
But, but, but... you're ruining the movie "The Matrix"! ;-)
- rienbdj 6y ago
  I wish The Matrix had humans in virtual reality cages because the AI had a mandate to keep them alive and well, and this was simply the most efficient mechanism for doing this. This would have made the resistance far more ambiguous as they would actually be fighting for freedom but against the well-being of humanity.
  - gruez 6y ago
    >I wish The Matrix had humans in virtual reality cages because the AI had a mandate to keep them alive and well Humans have finite lifespans, right? So all the AI has to do "relieve" itself of the burden of keeping humans alive would be to not let them reproduce. This would be pretty easy considering that it's pretty hard for people to spontaneously become pregnant while hooked up to those pods.
- frutiger 6y ago
  Apparently the original story had the AI use the network of human brains as a giant neural network. As the story goes, the movie executives thought this would be too difficult for most people to understand, so they switched it out and used the thermodynamically unviable power source motive instead.
WJW 6y ago
Just as a quick example: Bringing a pot with 1 litre of regular room temperature water to boiling temperature takes about 0.1 kWh. A regular person produces about 100W during strenuous but still aerobic exercise so you'd need about an hour of cycling to generate enough energy. This doesn't include heating the pot itself btw.
- angrysaki 6y ago
  Not disagreeing, but just wanted to point out that if the goal was to generate heat then humans could potentially be more efficient because of internal efficiency. The ballpark number I often see is 25% efficiency, so if you were able to somehow capture the waste heat they'd be able to heat up the water 3x as fast.
  - fastball 6y ago
    Fair point, though that is arguably the only situation involving electricity (besides heating the room itself which doesn't involve heat capture) in which you're actually trying to generate heat.
  - WJW 6y ago
    This would probably work better when heating up rooms rather than water. The benefit of using electricity as an intermediate form of power is that it becomes possible to heat water up to boiling temperature. Exercising humans never reach boiling temperature no matter how hard they try.
csunbird 6y ago
When you think about it, humans are really energy efficient at moving their limbs.
Xylakant 6y ago
You’re correct on the side of power generation, it’s a tiny amount. On the other side, we have come a long long way when it comes to efficiently using power. The combined power usage of my bathrooms lights is probably less than 60W. The largest MacBook uses less than a moderately trained human can produce. On average, fridges need paltry amounts, compared to what they needed a decade ago. Certainly, running a vacuum or boiling water won’t work with human power generation, but if you want that as a backup, you probably can fall back to a broom and use a gas/multifuel cooker in the meantime.
TylerE 6y ago
More importantly, I bet your hour a day user never comes close to the energy nessesary to build the bike and associates electronics in the first place
dheera 6y ago
Not only that, but human power is incredibly inefficient, especially if the food you are converting into that power is not plant-based. It's significantly better if you eat plant-based, but nowhere near a bunch of solar panels covering the same area that the plants did.
Panino 6y ago
> I think once you do the math > Literally forgetting to turn the light off in your bathroom twice a month 8h * 5W * 2 = 80Wh per month (Unless you're talking about using incandescent light bulbs, which would be like using a 4mpg vehicle in a discussion about average vehicle efficiency. Personally I think a 3W LED is better than a 5W, but I know most people disagree.) Our main bathroom light draws, I'd guess, 0.1W. It shows up as 0.0 with a kill-a-watt so I don't really know. And it's only used for about half an hour a day at most. > a super-committed, hour-every-day stationary-bike-using person 60W * 1 * 30 = 1800Wh per month So no, forgetting to turn a light bulb off for an entire night, twice a month, does not waste more electricity than that gained by a cyclist who is capturing their electricity. I think it's a great hack to turn this machine into an electrical generator.
- hn_throwaway_99 6y ago
  Come on, this is "missing the forest for the trees" pedantics. I think you will find that the average bathroom in the US uses way above 5W. Regardless, it's just an example. The DoE says the average US residential customer uses 909 kilowatt hours per month. Using your math of a committed cyclist that generates 1.8 kwh per month, you're still looking at under .2% of energy replacement. Which, again, even the smallest efficiency improvements in a house would completely dwarf what a human could produce.
  - Scoundreller 6y ago
    I really think room lights are approaching 5W/bulb. I have a 3x5w bulb setup and keep 2 unscrewed just because it’s too bright when I have to go in at night. Incandescents are a hard sell when LED bulbs are $1-$2 and pretty reliable.
  - Panino 6y ago
    I can only respond to your words. If you don't like my choice of bulb, then do your own math and show it like I did. See what watt bulb (not bulbs plural, or moving the goalposts even further, an entire bathroom) it takes for your assertion to be true. Actually I'll just do that myself because it's easy. Now, we already discussed generating 1800Wh per month using this bike. So: 1800 / (8 * 2) = 112.5 Or in other words: 112.5W * 8h * 2 = 1800Wh So you'd need to run a 112.5W light bulb for 8 hours per night, twice per month, just to equal the amount of electricity produced by the article author. Although you said that leaving the light on wasted more, so, let's just go with a 113W bulb. I'm old enough to remember 100W incandescent light bulbs, but even then, they were rarely bought and used because that's an insane amount of electricity for indoor lighting. Now where I live I can't even buy incandescent bulbs because they're not for sale. For 112.5W to be average, there would need to be millions of Americans using stadium lighting just to take a shit. I think you should take a step back and reflect on why you're so quick to attack someone for doing a cool hack (this is Hacker News) that reduces their electrical usage (in the time of climate change).
colechristensen 6y ago
A single square meter solar panel which costs on the order of $100 will outproduce a human. If you're camping or in a power outage and want to charge your phone or some led lights, sure, a bike charger makes sense, but you'll never be net positive with the energy you create vs. the energy needed to produce the generator.
- ezzaf 6y ago
  Solar panels only outperform a human when the sun is shining. From the article: "But what if skies remained gray for many days in a row? Rather than trying to purchase enough battery storage to cover all reasonable eventualities, I decided that my backup source of electricity needed a backup itself, one that I could use to charge that battery during times when my photovoltaic panels won’t function" As a primary source of energy a cycle generator doesn't make a lot of sense. But as an on demand source to cover occasional periods of low solar generation it's a great hack.
ForHackernews 6y ago
It's even crazier if you start comparing the energy used for training massive AI models vs. the paltry wattage required to keep a human brain operating.

layoutIfNeeded 6y ago

https://en.m.wikipedia.org/wiki/Fifteen_Million_Merits https://en.m.wikipedia.org/wiki/Fifteen_Million_Merits