Drought’s Impact On California’s Hydropower and What It Means For Clean Energy

Via MIT’s Technology Review, an article on how droughts are cutting into California’s hydropower and what that means for clean energy:

The droughts that swept across the western US in 2021 sparked wildfires and damaged crops. But the historic lack of water also had an impact on one of California’s key sources of renewable energy: hydropower.

Electricity generation from California hydropower plants was down 48% from the 10-year average, according to new data from the Energy Information Agency. And 2022 is looking even worse.

Hydropower is the world’s leading source of renewable energy, making up about 17% of electricity generation in 2020, but droughts in various regions are making it harder to rely on. As a low-carbon source of power, it’s essential in limiting emissions of carbon dioxide, especially because when a hydropower plant goes down, fossil fuels are usually used to make up the shortfall. 

Hydropower plants made up about 19% of electricity generation in California in 2019. Most are located in the northern part of the state, where reservoirs are fed by melting snowpack from the mountains. But droughts over the last two years have caused reservoirs to dry up. The second-largest one in the state, Lake Oroville, saw water levels drop so low in 2021 that the hydropower plant there was shut down for the first time in its history.

The lost power can’t easily be replaced with renewable sources that fluctuate during the day, like wind and solar. When California’s hydropower capacity dropped from 2019 to 2020, much of the difference was replaced by natural-gas generation and electricity imports from other states, according to data from the California Energy Commission.

Hydropower often comes under fire for its environmental impact, because dams disrupt ecosystems. In fact, California currently doesn’t count large hydropower plants in its renewable-power targets. But regardless of how it’s categorized, hydropower is a lower-emissions alternative to fossil fuels. 

During high-stress times on the grid, the reduced reliability of hydropower is already causing problems, says Brian Tarroja, an energy researcher at the University of California, Irvine. 

Last year, the Bootleg fire in neighboring Oregon affected several transmission lines in California at a time when soaring temperatures had increased electricity demand. Running hydropower plants at their drought-reduced capacity while ramping up natural-gas plants was barely enough to keep the power on

These difficulties are likely to continue, Tarroja says. Climate change is altering rainfall patterns and causing higher temperatures, even if overall precipitation stays constant. The effects are likely to challenge hydropower in the coming decades. 

Places with high levels of hydropower may need to start planning for the effects of climate change on power generation. That’s not just California: droughts in Brazil and China have also threatened hydropower capacity in recent years. 

There will be some natural variation from year to year, but reprieve isn’t likely to come soon. Compared with last year, reservoir levels right now are “considerably worse,” said Aleecia Gutierrez, deputy director of the California Energy Commission’s Energy Assessments Division, in an email. 

Other renewable energy sources could eventually provide more reliable power to the grid, bolstered by technologies like grid-scale battery installations. But for now, losses in hydropower will likely mean more electricity generation from fossil fuels, and more emissions. 

This entry was posted on Saturday, April 2nd, 2022 at 8:45 am and is filed under Uncategorized.  You can follow any responses to this entry through the RSS 2.0 feed.  Both comments and pings are currently closed. 

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About This Blog And Its Author
As the scarcity of water and energy continues to grow, the linkage between these two critical resources will become more defined and even more acute in the months ahead.  This blog is committed to analyzing and referencing articles, reports, and interviews that can help unlock the nascent, complex and expanding linkages between water and energy -- The Watergy Nexus -- and will endeavor to provide a central clearinghouse for insightful articles and comments for all to consider.

Educated at Yale University (Bachelor of Arts - History) and Harvard (Master in Public Policy - International Development), Monty Simus has held a lifelong interest in environmental and conservation issues, primarily as they relate to freshwater scarcity, renewable energy, and national park policy.  Working from a water-scarce base in Las Vegas with his wife and son, he is the founder of Water Politics, an organization dedicated to the identification and analysis of geopolitical water issues arising from the world’s growing and vast water deficits, and is also a co-founder of SmartMarkets, an eco-preneurial venture that applies web 2.0 technology and online social networking innovations to motivate energy & water conservation.  He previously worked for an independent power producer in Central Asia; co-authored an article appearing in the Summer 2010 issue of the Tulane Environmental Law Journal, titled: “The Water Ethic: The Inexorable Birth Of A Certain Alienable Right”; and authored an article appearing in the inaugural issue of Johns Hopkins University's Global Water Magazine in July 2010 titled: “H2Own: The Water Ethic and an Equitable Market for the Exchange of Individual Water Efficiency Credits.”