Bike Generators Waste Most of Your Pedal Power
Commercially Available Bike Generators Are Not Sustainable
Commercially available bike generators that charge batteries are highly inefficient, losing 42–67.5% of energy in conversion, plus additional losses from friction drives and poor rider position. A 150Wh lead-acid battery requires 500 hours of pedaling to offset its manufacturing energy, making the ecological benefit doubtful. Direct mechanical power transmission, as used in 19th-century pedal-powered machines, is far more efficient and sustainable.
When operating a bicycle generator you are basically pedalling to produce the energy required to manufacture the battery.
- erelong
Might have changed their attitude since then as they posted in 2022 about a DIY guide on making a bike generator: https://solar.lowtechmagazine.com/2022/03/how-to-build-a-pra...
- usrusr
Needs "2011" in the title. For example the section about friction drive hasn't been true for about a decade now
- rgmerk
This arguably had some relevance in 2011. In 2026, cheap solar and batteries make human-powered static devices that would benefit from the extra power of a stationary cyclist completely redundant.
- tocs3
Some things I would like to see are pedal controlled devices. Something like a pedal controlled wheelchair, not powered by the pedals just control the forward and back motion. My mother with sever arthritis can still pedal but has a very hard time walking. It would be a little exercise doing something that needs to be done (getting around). A pedal controlled remote control lawnmower would be nifty also.
- Mugshelf
Tried one at a demo; you put in a ton of work for minimal wattage. Much better off with a decent power bank, honestly.