Wind Turbine Yield for a carbon footprint

Lift rises almost linearly with angle of attack — until the airflow separates and the wing stalls, losing lift sharply. Drag has a fixed part plus induced drag that grows with lift squared and shrinks with aspect ratio. The lift-to-drag ratio, peaking at a modest angle, is the single number that governs a wing's efficiency.

Wind power scales with the cube of wind speed and the square of rotor diameter — which is why turbines keep getting bigger and why a windy site is worth so much more. No turbine can extract more than 59.3% of the wind's energy (the Betz limit); real machines reach about 45%. Below cut-in and above cut-out speeds they produce nothing.

LCOE spreads a power project's lifetime cost over every megawatt-hour it produces, letting wildly different technologies be compared fairly. It rewards high capacity factors and cheap capital, and punishes idle plants. The capital-recovery factor discounts future costs to today. It is the number that has made solar and wind the cheapest new power in most of the world.