An Electrifying Past

An Electrifying Past. . , On July 13, 1895, the electricity generated here and transmitted to Sacramento signaled the start of a nationwide change in the way we would light our homes and power our civilization. As this hydroelectric power plant was the first of its kind in Northern California, the project was no simple feat. Spread over two miles, the powerhouse used the force of water and new Alternating Current technology to generate enough electricity to power an entire city. The electricity was sent an unprecedented 22 miles for use in Sacramento, powering city light and a fleet of electric trolleys., This technological feat was made possible by the construction of a cut stone dam two miles upriver that diverted water into a canal parallel to the American River for delivery to a hydroelectric powerhouse. Since the grade of the river dropped significantly on its way past the town of Folsom, the use of a canal kept the water almost level. This retained the potential kinetic energy of the water for use at the powerhouse., Prisoners from the adjacent Folsom Prison not only quarried all the rock, but were the labor force used for building the dam and the canal. Prisoners also cut the stone for the powerhouse foundation. The brick used to build the powerhouse came from the nearby Sacramento Valley Railroad buildings that had been dismantled., Here at this end of the canal, from the forebay above the powerhouse, water drops 55 feet through large penstock pipes feeding into the powerhouse. Each penstock pipe provided water to spin a set of paired turbines, which rotated Alternating Current electrical generators. Combined, all four turbine generator sets could produce 3,000 kilowatts of power at 800 volts, or the equivalent of 4,022 horsepower. To increase long distance power transmission efficiency, nearby transformers increased the voltage to 11,000 volts., Due to drought conditions and low river levels, the lower powerhouse was added in 1897, taking advantage of the energy available from the water discharged by the main powerhouse. , . This historical marker was erected by California State Parks. It is in Folsom in Sacramento County California