This text explains how the U.S. electricity system generates power, moves it to customers, sets wholesale prices, and maintains a steady 60 Hz frequency despite having almost no way to store electricity at grid scale. It describes an interactive, roughly Texas-sized model that mirrors the national generation mix and lets users change demand, weather, fuel prices, and operating conditions, or explore events such as storms and blackouts. The scale is substantial: U.S. generation reached 4,528 TWh in 2025, while transmission and distribution lose about 5% of electricity as heat. Because supply must match demand moment by moment, plant failures and demand spikes affect frequency, reserves, and prices.
The generation sources differ in cost and flexibility. Natural gas supplied 40.2% of 2025 electricity and often sets market prices; efficient combined-cycle plants burn less fuel than quick-start peakers, whose expense pushes prices up during peak demand. Coal supplied 16.3%, offering stored fuel and grid inertia but producing heavy emissions and operating inflexibly. Nuclear provided 17.3% with high reliability and low running costs, though new construction is costly and plants cannot restart a dead grid unaided. Hydropower is highly efficient, dispatchable, and useful for black starts, but depends on water availability. Wind contributed 10.3%; its output varies with wind speed, and subsidized farms may bid below zero when supply exceeds demand.
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