Physics: Why Wind Supply Often Falls Short of Demand

Wind turbines turn the kinetic energy of moving air into electricity: the wind forces the blades to rotate, and the spinning rotor drives a generator, where electromagnetic induction converts rotational kinetic energy into electrical energy. This chain — kinetic to mechanical to electrical — makes wind a renewable resource, since no fuel is consumed and no greenhouse gases are emitted during operation. Understanding this matters because a town's demand must be matched continuously, not just on average. Each turbine has a rated output, so the combined supply from several turbines is their individual outputs added together. That total only equals demand when every turbine runs at its rated wind speed, and wind is variable and intermittent, so output often falls short. Maintenance and mechanical failure add further gaps. Weighing this reliability against wind's environmental and societal benefits — lower emissions and fuel costs, but impacts on wildlife and landscape — is the heart of judging whether wind can be a primary electricity source.