Froude theory (cont)
220 lb asks for 2.2kW. It is only the minimum power required to produce the momentum and lift that weight (assuming 100% efficiency). The drag of the blades and the antitorque are additional power.
The power increases with power 3/2 of the weight and directly decreases with the diameter. With a 30m diameter, you would be close to a 0.7kW (1sHp) level.
These figures apply to HOGE. In HIGE, very close to the ground, you can gain 20-25%.