the lowdown on free-wheeling shaft generators?
1 Horsepower = 747 Watts at 100% efficiency.
Watts = Volts x Amps, and Amps = Watts / Volts.
Read the equipment specifications, and you can calculate the minimum (it''ll likely be about 50% more) H.P. drag the generator will impose.
These devices, in my opinion, are not usually worth the capital & operating cost. Operating cost, you ask? Any machinery requires maintenance & repair, both to itself & to it''s associated machinery. There''s no free lunch!