Folsom Powerhouse was one of the earliest electrical plants to generate three-phase alternating current, and the first using three-phase 60 hertz. On 13 July 1895, General Electric generators began transmitting electricity 22 miles to Sacramento at 11000 volts, powering businesses, streetcars, and California’s capitol. The plant demonstrated advantages of three-phase, 60 hertz long-distance transmission, which became standard, and promoted nationwide development of affordable hydropower.
13 July 2021: 10:00 a.m. PT (UTC 17:00) Folsom Powerhouse Milestone Dedication.
For more details, see the Folsom Powerhouse State Historic Park on FaceBook.