I’m not familiar with the mechanics of electricity generation and such, so I’m curious if there are good reasons why this isn’t possible or useful.
Edit: thanks for the great responses! I gather that the main problems revolve around the fact that it will take more energy to outfit the machinery and feed the people than you’ll get in return.
In: 5
Yes and no.
An elite cyclist can produce around 400 Watts of mechanical power for over a hour and bursts of 1000 to 1100 watts.
An adult of good fitness will produce around 50 and 150 watts on average during vigorous exercise. A manual laborer can sustain 75 watts for an 8 hours work shift.
75Watts for 8 hours is 75 * 8/1000 =0.6kWh that is with a 100% efficent generator
The average EU electricity usage per capita in the household sector was 1569kWh = 4.3kWh per day. So a human that tries to power a generator for 8 hours per day will produce 1/7 of the average electricity usage.
The average electricity cost in EU was 28.3 c€/kWh so you produce 17 cents of electricity per day. I would assume that the extra food you need to eat to do that work cost more.
The practical result is that human power electric generation has been use for military radio equipment. There as been portable hand crank systems and just bicycles in a fixed installation. You can find hand-crank-powered emergency radios today.
The more common application is the illumination of bicycles for time usage. There are today bicycle kits that you can use to change up your cell phone when you use the bike. The cost of a system like that will be equal to years of changing the phone from a wall outlet so unless you have multiple-day bicycle touring. The same for an exercise bike, adding parts that make it possible to use the energy will just increase the cost of the bike more than the value of the electricity you get out.
https://en.wikipedia.org/wiki/Human_power
So unless you use it as a backup for low-power usage applications when you do not have access to a power grid or when it is out is it not worth it.
Something like this was actually done as an experiment for a TV show in Britain a few years ago to look into energy efficiency and wastefulness. A ‘regular’ family (2 parents, 2 approx. teen kids IIRC) had their house connected to generators connected to a fleet of exercise bikes and volunteers pedalled them to supply the energy.
The upshot was a lot of exhausted cyclists when the kids (especially) kept leaving lights on while not in rooms etc. They apparently did feel quite guilty afterwards and promised to change their ways but who knows…
Think of it like a trade. Assuming you had a power-generating bike already, you are trading time, effort, and the food it takes to fuel a person, for only a little bit of electricity.
There are times this might be worth it, like in a post disaster scenario where there’s plenty of food and time and no other way to generate power. You might get on the bike and power a radio to call others, and that would be very worth it. But if you are asking if in the present day it would it save money or energy, no, because we aren’t very efficient engines at turning one source of energy (food) into another (electrical charge).
You might think that there are some scenarios now where people are biking on stationary bikes at gyms and they are paying to do so, and that power output which they’re already doing because it serves as their exercise could definitely be used to at least charge a phone. But remember that we started our thinking with the person already having access to a power generating bike. In reality it costs a lot to add that functionality to an exercise bike in a safe and reliable way, so even when the person wants to pedal and spend that energy, it’s rarely efficient to provide the equipment even to paying customers for how little electricity we can create.
Yes and no.
An elite cyclist can produce around 400 Watts of mechanical power for over a hour and bursts of 1000 to 1100 watts.
An adult of good fitness will produce around 50 and 150 watts on average during vigorous exercise. A manual laborer can sustain 75 watts for an 8 hours work shift.
75Watts for 8 hours is 75 * 8/1000 =0.6kWh that is with a 100% efficent generator
The average EU electricity usage per capita in the household sector was 1569kWh = 4.3kWh per day. So a human that tries to power a generator for 8 hours per day will produce 1/7 of the average electricity usage.
The average electricity cost in EU was 28.3 c€/kWh so you produce 17 cents of electricity per day. I would assume that the extra food you need to eat to do that work cost more.
The practical result is that human power electric generation has been use for military radio equipment. There as been portable hand crank systems and just bicycles in a fixed installation. You can find hand-crank-powered emergency radios today.
The more common application is the illumination of bicycles for time usage. There are today bicycle kits that you can use to change up your cell phone when you use the bike. The cost of a system like that will be equal to years of changing the phone from a wall outlet so unless you have multiple-day bicycle touring. The same for an exercise bike, adding parts that make it possible to use the energy will just increase the cost of the bike more than the value of the electricity you get out.
https://en.wikipedia.org/wiki/Human_power
So unless you use it as a backup for low-power usage applications when you do not have access to a power grid or when it is out is it not worth it.
Something like this was actually done as an experiment for a TV show in Britain a few years ago to look into energy efficiency and wastefulness. A ‘regular’ family (2 parents, 2 approx. teen kids IIRC) had their house connected to generators connected to a fleet of exercise bikes and volunteers pedalled them to supply the energy.
The upshot was a lot of exhausted cyclists when the kids (especially) kept leaving lights on while not in rooms etc. They apparently did feel quite guilty afterwards and promised to change their ways but who knows…
Something like this was actually done as an experiment for a TV show in Britain a few years ago to look into energy efficiency and wastefulness. A ‘regular’ family (2 parents, 2 approx. teen kids IIRC) had their house connected to generators connected to a fleet of exercise bikes and volunteers pedalled them to supply the energy.
The upshot was a lot of exhausted cyclists when the kids (especially) kept leaving lights on while not in rooms etc. They apparently did feel quite guilty afterwards and promised to change their ways but who knows…
Yes and no.
An elite cyclist can produce around 400 Watts of mechanical power for over a hour and bursts of 1000 to 1100 watts.
An adult of good fitness will produce around 50 and 150 watts on average during vigorous exercise. A manual laborer can sustain 75 watts for an 8 hours work shift.
75Watts for 8 hours is 75 * 8/1000 =0.6kWh that is with a 100% efficent generator
The average EU electricity usage per capita in the household sector was 1569kWh = 4.3kWh per day. So a human that tries to power a generator for 8 hours per day will produce 1/7 of the average electricity usage.
The average electricity cost in EU was 28.3 c€/kWh so you produce 17 cents of electricity per day. I would assume that the extra food you need to eat to do that work cost more.
The practical result is that human power electric generation has been use for military radio equipment. There as been portable hand crank systems and just bicycles in a fixed installation. You can find hand-crank-powered emergency radios today.
The more common application is the illumination of bicycles for time usage. There are today bicycle kits that you can use to change up your cell phone when you use the bike. The cost of a system like that will be equal to years of changing the phone from a wall outlet so unless you have multiple-day bicycle touring. The same for an exercise bike, adding parts that make it possible to use the energy will just increase the cost of the bike more than the value of the electricity you get out.
https://en.wikipedia.org/wiki/Human_power
So unless you use it as a backup for low-power usage applications when you do not have access to a power grid or when it is out is it not worth it.
Depends on what you mean by useful amounts. The amount of energy you get out will always be much lower than what you put in.
Back in the days before LED lights, many bikes would have a small dynamo that could be driven by the tire to power a headlight. That’s certainly useful if you’re biking home in the dark. But it makes pedaling noticeable harder so you’d only use it when it was really needed.
https://discerningcyclist.com/what-is-bicycle-dynamo/
Depends on what you mean by useful amounts. The amount of energy you get out will always be much lower than what you put in.
Back in the days before LED lights, many bikes would have a small dynamo that could be driven by the tire to power a headlight. That’s certainly useful if you’re biking home in the dark. But it makes pedaling noticeable harder so you’d only use it when it was really needed.
https://discerningcyclist.com/what-is-bicycle-dynamo/
Depends on what you mean by useful amounts. The amount of energy you get out will always be much lower than what you put in.
Back in the days before LED lights, many bikes would have a small dynamo that could be driven by the tire to power a headlight. That’s certainly useful if you’re biking home in the dark. But it makes pedaling noticeable harder so you’d only use it when it was really needed.
https://discerningcyclist.com/what-is-bicycle-dynamo/
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