Folsom in Sacramento County, California — The American West (Pacific Coastal)
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
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.
Erected by California State Parks.
Topics. This historical marker is listed in this topic list: Industry & Commerce. A significant historical date for this entry is July 13, 1895.
Location. 38° 40.826′ N, 121° 10.596′ W. Marker is in Folsom, California, in Sacramento County. Marker can be reached from Greenback Lane. Touch for map. Marker is in this post office area: Folsom CA 95630, United States of America. Touch for directions.
Other nearby markers. At least 8 other markers are within walking distance of this marker. Original Folsom Hydroelectric Plant (a few steps Cutting Edge Technology (within shouting distance of this marker); Lower Powerhouse (within shouting distance of this marker); Pushing Electrons (within shouting distance of this marker); Main Powerhouse (within shouting distance of this marker); Forebay (about 400 feet away, measured in a direct line); J. Clifton Toney (approx. 0.2 miles away); Ashland Station (approx. Ό mile away). Touch for a list and map of all markers in Folsom.
More about this marker. The marker is located in Folsom Powerhouse State Historic Park, between the visitor center and the machine shop.
Also see . . . The Folsom Powerhouse (California State Parks). An essay length description of the development of the dam and powerhouse. (Submitted on February 25, 2022.)
Credits. This page was last revised on February 25, 2022. It was originally submitted on February 25, 2022, by Andrew Ruppenstein of Lamorinda, California. This page has been viewed 79 times since then and 8 times this year. Photos: 1, 2, 3. submitted on February 25, 2022, by Andrew Ruppenstein of Lamorinda, California.