A wind turbine is a machine that converts wind kinetic energy into electricity. The wind turns blades. The blades turn a rotor. The rotor turns a generator. The generator produces electricity. A single modern turbine can power hundreds of homes. A wind farm can power a city.

Turbines come in two main types. Horizontal-axis turbines have blades on a horizontal shaft, like a propeller. They are the most common. Vertical-axis turbines have blades on a vertical shaft. They are less common but work in turbulent wind. Offshore turbines are larger and capture stronger, steadier winds.

Key components

• Blades: capture wind energy
• Rotor: connects blades to shaft
• Nacelle: housing for gearbox and generator
• Tower: supports the rotor
• Foundation: anchors to ground or seabed

Wind power is one of the cheapest sources of electricity. Costs have fallen over 70% since 2010. But wind is intermittent. Storage and grid upgrades are needed. Turbines also face opposition for visual and noise impacts. The energy is clean. The politics are not.