The Electron Hydropower Project is located on the Puyallup River in Pierce County, Washington. The Project begins about six miles west of Mt. Rainier National Park. Water is diverted from the river along a 10.2 mile wooden flume (topped with a railroad) to a forebay, then plunges 875 feet downhill through steel penstocks to the 26 megawatt Powerhouse. The Project produces enough renewable energy to power more than 20,000 homes.
Electron is a run-of-river project, there is no water storage from a large dam and reservoir like the big hydropower projects on the Columbia and Snake rivers. The upper Puyallup River is fed by direct precipitation and the melting snow and glacier fields of Mt. Rainier. This natural feature allows Electron to continue to generate clean power well throughout the summer with only a modest reduction in capacity by early Fall. Soon the November storms bring the project back up to full capacity again!
The Project diverts up to 400 cubic feet of water per second (cfs), and must maintain minimum instream flows for all aquatic life living downstream in the river reach before diverted flow returns to the river from the Powerhouse. At times river flow substantially exceeds the project capacity, recently exceeding 10,000 cfs three different times within a thirteen month period! These mega-flows sweep over the diversion structure taking large boulders, cobble and sediment with them downstream. The Project is being upgraded with a new 70 foot long by 12 foot diameter air bladder spillway to provide for this sediment transport while keeping these materials from entering the flume. This work began the summer of 2018.
Renewable energy made here!