Out West student blog

Pumped Storage Hydropower as an Answer to California’s Energy Needs

The impoundment at Oroville Dam, left, whose releases are turned into energy by generators, right, at the Hyatt Powerplant down below. With pumped storage, a pump-generator would send water back up above the dam during inexpensive power periods and use it to generate hydropower during peak hours. (Credit: California Department of Water Resources)

By Barrett Travis
Civil & Environmental Engineering (Env. Fluid Mechanics), 2018
Energy Intern, California Department of Water Resources



Last month, The New York Times published an article titled “The $3 Billion Plan to Turn Hoover Dam into a Giant Battery.” The plan would be to install pumps that could bring water to Lake Mead from below Hoover Dam during “cheap” electricity hours – in the middle of the day, solar production is sometimes more than the power grid needs – and then run that water back through the dam’s current generators when the sun is not shining and power is in high demand. While I am not sure of the feasibility of this particular proposed project, it was interesting to see pumped storage get national attention as I work on a related study for the California Department of Water Resources this summer.

My office, the Power and Risk Office, works on energy matters related to the operation of the State Water Project (SWP). The SWP is actively adapting its hydroelectric generation and water pumping, when it can, to respond to the changing daily price structure of California electricity (mainly a result of increasing solar power in the state) and otherwise offer services to the power grid to make sure that California always has power. While several SWP facilities already use pumped storage in some capacity, the energy storage strategy may have greater future potential.

Barrett Travis (standing) discusses his work at an SEIC (Stanford Energy Internships in California & Colorado) event in Sacramento on August 8th. (Photo credit: Stephanie Burbank)

This summer, I have been working with others in the Power and Risk Office to adapt a pumped storage financial model to analyze current and future conditions at Oroville, where two powerplants already produce a significant amount of electricity as water is released to the Feather River from Lake Oroville in accordance with water delivery schedules, ecological needs and flood management protocols. Going into the model are: future power price forecasts; hydrologic (water flow) scenarios that consider the effects of climate change and the California WaterFix project; and maintenance schedules that affect the availability of generators at each of the two powerplants. We use a financial software to determine the market opportunity for pumped storage based on simulations of hourly energy prices through the coming decades, and then we apply water delivery constraints to identify the actual value of Oroville’s pumped storage capacity for each hydrologic scenario. When the project is completed in the next few weeks, the analysis will help inform pumped storage use and other potential future projects in the Oroville area.

This summer has opened my eyes to the complicated, but rewarding, work of public service. As the July New York Times article suggests, pumped storage may be an essential part of helping California and the rest of the country transition fully to solar power and other intermittent but clean sources of energy. The opportunity to make a positive impact on communities (and the environment) through my work was the main reason I pursued a Master’s degree in Civil and Environmental Engineering, and it has been a privilege to see directly this summer how technology and policy are driving a more sustainable future for California.

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