Wind Generators.

[anotheoldgit]

Could anyone explain to me, when the old Windmills needed such very large sails, how the arms of wind generators catch the wind, when their blades are so narrow.

[bhg481]

The blades are designed to be more efficient ie, they take more of the energy out of the wind and convert it to electrical energy.

[paul1763]

maybe turning 2 grinding stones which rub together causes more resistance than turning a few gears.

[beso]

Put simply.

The tips of the blades on a modern electricity generating wind turbine travel several times faster than the wind. So those thin blades sweep across a large arc before the wind gets out the other side.