Wind Energy

Power in wind comes from moving mass, and kinetic energy depends on velocity squared. But the amount of air hitting the blades each second also depends on speed, so you get another factor of velocity. Multiply those together and power scales with velocity cubed: double the wind speed and you push eight times as much energy into the blades per second. That cube relationship is why turbine siting matters so much. A site with modestly higher average wind speed can produce far more energy than the math of "a bit windier" suggests.

Mechanically, wind pushes on angled blades shaped like airplane wings, and the pressure difference across them creates lift that spins the rotor. The rotor turns a low-speed shaft connected to a gearbox, which steps up the rotation to the high speed a generator needs to produce electricity efficiently. That electricity runs through transformers and onto transmission lines. Because wind speed is never constant, turbines never run at their rated maximum all the time. Capacity factor captures that gap: actual annual energy output divided by the output the turbine would produce running at rated power for all 8760 hours of the year.

Turbines placed close together interfere with each other. A downwind turbine sits in the wake of the one ahead, where air has already given up energy and become slower and more turbulent, so the downwind turbine generates less power and suffers more mechanical stress. This is why wind farm layout spreads turbines apart and accounts for prevailing wind direction. It connects to the same intermittency question that applies to solar: no single turbine or site runs at full output constantly, but grid operators manage that variability across many sites, storage, and flexible backup rather than relying on any one turbine.