Re: Air is elastic
If the wind stopped, the air would pile up at the turbine. You need to bring air out at the same rate it goes in mass-wise, but at lower speed, which means higher density. So part of the incoming kinetic energy has to go into compressing the air, which imposes a theoretical maximum efficiency. The Betz limit, or about 60%. Practical turbines tend to be around 50% at most, because achieving that last few percent is disproportionately expensive.
Biting the hand that feeds IT
