Is it feasible to generate useful amounts of electricity by having people manually generate it, e.g. by riding an exercise bike?

Question

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

Answer 1

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.