Seems to me that a hub motor could generate a decent amount of power if used on a small wind turbine? On the subject of power generation, why is there a downer for regeneration on ebikes - what are the actual numbers and facts?
I doubt if the output would be particularly good compared with a generator design. In motor form they are designed for economy of course. Working in reverse mode as a generator we need the opposite of course, the profligate output that a dedicated generator design gives.
As for e-bike regeneration, it's simply the lack of mass of a rider and e-bike coupled with the low bicycle speeds that make it unproductive. Earlier attempts with geared hub motors by the Birkestrand Corporation with their "magic wheel", Sanyo with their hub motor and and the Chinese with some of their cheaper e-bikes have all failed and disappeared. Only BionX with their direct drive motor retain it, but even there it only exists in an optional switched mode which few owners bother to use.
Panasonic have 3000 bikes on long term trial in Japan with front hub motors which are braking regenerators. They claim a massive increase in range of about 50% which is pure nonsense. No cyclist with any sense would do that much braking, since it implies a huge effort to put in both that much surplus energy in the first place plus the extra required to account for energy conversion effciency loss. The best cyclists avoid braking as much as possible of course to conserve their energy or to utilise downhill speed gain as kinetic energy directly wherever possible.
It's sobering to consider that the Formula 1 world has struggled to make their KERS braking generation energy recovery system work. There we have half ton cars losing most of 200 mph in as little as three seconds!!! If that massive potential can't easily pay off, what hope is there for a one-tenth ton rider and bike losing only 10 mph in a few seconds?
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