The Folsom Powerhouse

In July eighteen ninety-five, a stone building on the American River accomplished something that most engineers in the country thought was barely possible at commercial scale. It transmitted alternating-current electricity twenty-two miles downstream to Sacramento, the longest AC power transmission in the United States at that moment.

To understand why that was remarkable, you have to understand where the technology stood. George Westinghouse and Nikola Tesla had demonstrated, in the early eighteen-nineties, that AC power could theoretically be transmitted over long distances without the catastrophic losses that plagued direct current systems. The Niagara Falls hydroelectric project was still being engineered. Long-distance AC transmission at commercial scale, meaning a system actually serving a city, had not been done.

Folsom did it.

The Sacramento Electric Power and Light Company designed the system. Water from the American River drove generators inside this stone powerhouse. The electricity traveled twenty-two miles of copper wire and arrived in Sacramento strong enough to light the city's streets and run its streetcar system. The people who drove those streetcars and read by those electric lights were living in the future as most Americans still understood it.

The original generators from eighteen ninety-five are still in this building. They have not run commercially since the powerhouse was decommissioned in the nineteen-fifties, but they are intact, which is to say they are among the oldest large-scale AC generators in the country still in their original location. This is where the modern electrical grid, the one that runs everything you depend on, was proven to work.