I would still think that something much simpler (and "bycicle based") together with a battery could be much more useful in places where there is no mains and fo

I would still think that something much simpler (and "bycicle based") together with a battery could be much more useful in places where there is no mains and for emergencies. Something loosely like : https://www.electricpedals.com/pedal-generators https://www.electricpedals.com/pedal-generators It seems like 60-80 W are sustainable for a longish period of time, so say half an hour that should be doable could be 40 Wh, something like 4 hours 10 W or 8 hour for a 5W led lamp. I always thought that (for people sitting on a couch watching TV and not moving/walking/biking enough) connecting a small TV to the generator (with a minimal cache battery) could be a good product (though I doubt anyone would ever actually buy it).