Thomas Edison flipped the switch on the country’s first power plant in Manhattan in 1882, and in the years that followed, more than 4,000 individual electric utilities provided electricity for an increasingly modern society. But each utility operated independently, and after World War II, the demand for power began to ramp up. Electric utilities found it more efficient to connect their transmission systems into a power grid, and over time, three large interconnected systems evolved in the United States: the Eastern Interconnection and the Western Interconnection for most of the country, and the Texas Interconnection for, well, Texas.
The Electric Reliability Council of Texas (ERCOT) grew from that state’s long-lived independent streak, and its utilities only serve Texas customers. The state’s homegrown power serves most of the state, except for El Paso, the upper panhandle, and a hunk of east Texas. And by not selling to interstate customers, ERCOT is exempt from most federal regulation.
Even power use is bigger in Texas: