Penstocks
Penstocks are used in projects that produce electricity using hydroelectric power plants integrated into the design of the dam.
“The penstock conveys water from the intake structure to the powerhouse and can take many configurations, depending upon the project layout. Where the powerhouse is an integral part of the dam, the penstock is simply a passage through the upstream portion of the dam. A canal, pipe, or tunnel is required where the powerhouse is separated from the intake. A penstock may be several miles long at diversion-type projects. Water may be conveyed most of the distance at an elevation close to the forebay elevation via an open canal or a low pressure pipe or tunnel. The remainder of the penstock, where most of the drop in elevation occurs, would be a pressurized tunnel or pipe. Because the cost of a pressurized tunnel or pipe is much greater than that of a low pressure tunnel or pipe, it is usually desirable to minimize the length of the high pressure penstock. When the powerhouse is located adjacent to the dam but is not an integral part of the structure, water would be conveyed through or around the dam via a pressure tunnel. For multi-unit installations, it is often desirable to serve several units with a single penstock, and manifolds or bifurcation structures are provided to direct flow to individual units”.[1]
Best Practices Resources
Engineering Guidelines for the Evaluation of Hydropower Projects: Chapter 12- Water Conveyance, FERC
Citations:
Revision ID: 7143
Revision Date: 07/11/2023