I was curious whether they talked about the practicality of the whole setup, and they do, e.g.<p>> Electric kettles that run on grid power are often very powerful and boil water in a matter of minutes or even seconds. Boiling water using a bicycle generator will take a lot more time, but it’s perfectly possible. We acquired a commercial 12V electric kettle with a vacuum insulated reservoir of one litre. During a test, boiling water for one cup of tea took slightly more than one hour at an average power production of 60W.<p>To be honest, although I realize it would be ridiculous, but if inverters were small and cheap, I would personally prefer having an exercise bike plugged into the grid. That way my exercise energy would at least be useful to someone, somewhere.
FWIW: <a href="https://www.lowtechmagazine.com/2022/03/how-to-build-bike-generator.html" rel="nofollow">https://www.lowtechmagazine.com/2022/03/how-to-build-bike-ge...</a> is much easier to read. The current link is the version of the site where the server runs off of solar power.
Alright - this is mostly off topic, but I see this website pop up here fairly frequently, and I really <i>really</i> hate the battery level indicator.<p>I find it makes reading the actual content far more difficult than it should be.<p>I get that it's intentionally drawing attention to the fact that this site is solar powered, but it pulls my eye to the line literally every time I scroll.<p>I end up closing the tab out without finishing the article - it bothers me so much.<p>Personally - I'd really love to have an option to hide it. I'm completely down for showing it by default - but after a minute or two on the site, the novelty has worn off and I'd really rather focus on reading your content.
I'm impressed at the relatively high efficiency of the system. Pedalling at 150 watts and recovering 100 watts of electricity is higher than I would have expected from such a simple system.<p>I'm very curious how much better the system would perform if the flywheel were attached directly to the drive-train instead of via friction roller. In practice this might not give much higher efficiency, but I would guess that the chain and primary sprocket would wear out slower than a tire friction-running a flywheel.<p>(They mention that they don't do this because this because it would be harder to build. I believe that. But I'm still curious.)
A rowing machine employs a wider range of muscles and so will enable more power to be produced. Here's a DIY rowing generator that one guy built:<p><a href="https://www.lybrary.com/a-rowing-machine-which-generates-electricity-a-36.html" rel="nofollow">https://www.lybrary.com/a-rowing-machine-which-generates-ele...</a><p>He claims 100W steady output but I'm sure more is possible.<p>One advantage of the bike over a rower is you can be doing other things at the same time, like reading a book, or tapping on a phone or keyboard. On a rower ,only passive activities like listening to music or watching a screen are realistically possible.
150W is a pretty good workout sustained for an hour. Humans can do what, maybe 1000W or so at peak? Non-athletes, I mean. But nobody is putting out 1000W for very long. I'd have guessed that over an hour 75W-100W is more realistic. I recall playing around with a bike generator at the local power plant about 30 years ago and it was <i>hard</i> to keep a regular light bulb lit for any length of time.
One kiloWatt-hour of electricity costs around $.24 in my state. If you can output 100 Watts for 1 hour, that’s .1 kWH. Do it every day for a year that’s ~36 kWH, or about $10 in electricity.
One thing I think that could be changed here is a different storage medium. For example, flywheel storage instead of batteries, or compressed air storage, instead of batteries. Since batteries can't be charged faster than a certain rate, it creates a limitation. Of course, compressed air is only so useful and not so efficient to turn into electricity but, still an idea.
I know this is way off-topic but in Calum’s YouTube video about British Intelligence in Gibraltar he mentions a pedal-powered generator which was the primary source of power for the agents working deep inside the bunker.<p><a href="https://youtu.be/2n97nh9PKH4" rel="nofollow">https://youtu.be/2n97nh9PKH4</a>
If I were to create such a system today I would take advantage of an inexpensive (~$10-$20) MPPT (maximum power point tracking) solar controller to regulate the unruly DC output of the generator or rectified alternator. It will sweep the input voltage/amperage to find the maximum power production for a given power source. These devices will automatically charge either a 12v or 24v battery and also provide several 2a USB ports for device charging.
Reminds me of the toaster challenge video[1] where Robert Förstemann, German track cyclist, powers a 700 Watt toaster for over a minute on an exercise bike. Absolutely insane.<p>[1]: <a href="https://www.youtube.com/watch?v=S4O5voOCqAQ" rel="nofollow">https://www.youtube.com/watch?v=S4O5voOCqAQ</a>
The main reason I want a bike generator is to power my laptop, so that if I'm going to be sucked into web browsing regardless, I'll at least have to get some exercise in the process.