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

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.