California's hydroelectricity production is vulnerable to climate change

August 7, 2012 By Iqbal Pittalwala
Distribution of hydropower plants in California.

( -- California’s hydropower is vulnerable to climate change, a University of California, Riverside scientist has advised policymakers in “Our Changing Climate,” a report released July 31 by the California Natural Resources Agency and the California Energy Commission (CEC).

“Climate change is expected to affect the quantity and timing of water flow in the state,” explained Kaveh Madani, a former postdoctoral research scholar in UC Riverside’s Water Science and Policy Center (WSPC), who led a research project on climate change effects on hydropower production, demand, and pricing in California.   “Under dry climate warming, the state will receive less precipitation, with most of it as rain instead of snow, impacting hydropower supply and operations.”

On average, 15 percent of California’s electricity comes from hydropower, a cheap and relatively clean energy source.  About 75 percent of this hydropower comes from high-elevation units, located above 1,000 ft. The state has more than 150 high-elevation units, with most of them located in Northern California and the Sierra Mountains. The majority of the high-elevation reservoirs are small in terms of their storage capacity, being built only for hydroelectricity production and no other benefits, such as water supply and flood control.

“If California loses snowpack under climate warming, these high-elevation reservoirs might not be able to store enough water for hydropower generation in summer months when the demand is much higher and hydropower is priced higher,” said Madani, currently an assistant professor of civil, environmental, and construction engineering at the University of Central Florida. “California might, therefore, lose hydropower in warmer months and hydropower operators may lose considerable revenues.”

Madani, who led UCR’s only research team for CEC’s third climate change assessment studies, explained that the major cause of revenue loss is that hydropower prices are expected to decrease in colder months of the year and increase in warmer months.

“The big problem is that hydropower will be less available when it is most needed and expensive: in the summer months,” he said. “A warmer California needs more electricity for cooling in summer months and less electricity for warming in winter months. This means that hydropower pricing patterns will be affected by climate change. It is important to analyze climate change effects on this renewable energy source early on to figure out what strategies are available to adapt to the new conditions and thereby minimize the potential negative impacts of climate change on hydropower.”

Madani explained that, on average, California could lose up to 20 percent of its hydropower generation under dry climate change, which can result in 8 to 18 percent reduction in hydropower revenues for producers.

“Our results do not yet suggest that we need to build more dams in California for hydropower generation,” said Madani, who was recently selected as one of the 10 New Faces of Civil Engineering in 2012 by the American Society of Civil Engineering. “But they suggest that hydropower, a highly valuable energy source, may be less available. So we have to look for clean replacements and we have to reduce our energy demands as much as we can.”

Madani began his research on effects on California’s hydropower as a graduate student at UC Davis, where, along with a colleague, he developed an “Energy-Based Hydropower Optimization Model” (EBHOM) that covers more than 150 high-elevation hydropower units in . An optimization model, EBHOM prescribes the best operation policies in response to the changes in climatic conditions.

A new version of the model that Madani developed can estimate changes in hydropower pricing and demand in response to temperature changes.

“It helps us consider the effects on supply and demand simultaneously,” Madani said of the model’s new version.  “But modeling studies have limitations that need to be addressed as more data become available and the science improves.  Future studies need to have a closer look at the environmental side of this problem.  Changes in operations of the high-elevation systems should be done after careful consideration of all possible environmental damages.”

Madani’s research at UCR was funded by CEC.  As the principal investigator of the research project, he worked with fellow-researchers at Lund University, Sweden; the University of Central Florida; and the Bourns College of Engineering at UCR.

Madani’s postdoctoral research took place during 2009-2010 at the WSPC, where he closely worked with Ariel Dinar, its director.

“I am an engineer and Ariel is an economist,” Madani said. “We talk different languages and sometimes might think differently about the same problem. The different views helped me learn many new things and gave me the ability to think out of the engineering thinking box. Working at the WSPC was thus a true interdisciplinary research and education experience for me.”

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4 / 5 (4) Aug 07, 2012
California rainfall has never had a guarantee.
not rated yet Aug 07, 2012

Folks it's not just Cal but east of the Rockies too big time. We need to build new dams high up to save rainfall that use to be snowfall or it's going to be flood and drought.
Aug 07, 2012
This comment has been removed by a moderator.
3 / 5 (4) Aug 07, 2012
Eco-nuts say think globally act locally.
How many are acting locally to change zoning laws and promote housing such as concrete monolithic domes? They are nearly fire proof, earthquake proof and very energy efficient.

3 / 5 (2) Aug 07, 2012
CA is already doing it, but just build more solar. Both local/home roof top types, and the big solar thermal types. It can more than make up for the intermittent loss of Hydro-electric.

But as a bone for R2 to chew on, CA prefers clean and green energy to black and dirty. I don't think you'll get them to select otherwise.

3 / 5 (4) Aug 07, 2012
No, CA wants others to have the coal fired plants, but they don't care where the energy comes from.
That was one of the motivations behind their re-regulation debacle in 2000. CA would buy its power from out of state instead of building more generating plants in state.
not rated yet Aug 07, 2012
California needs to build more modern pumped storage facilities to store rain water and use it during periods of high demand.

But it won't.

Oh, and this all bodes ill for the coming initiative to remove Hetch Hetchy reservoir. Nature takes it in the rear end .... again.
1 / 5 (1) Aug 07, 2012
Best way to fight drought is to plant loads of trees to give shade to the soil so that it remains moist even during long periods of drought. no battery or dam competes against that.
2.3 / 5 (3) Aug 08, 2012
Constructing more nuclear power plants was considered by the editors to be 'pointless verbiage'.
It is a solution to the problem presented by the editors and is tossed out.
So what are the editors trying point out in this story? Trying to pile on to the AGW story? Blame more problems on AGW?
Why not promote technical solutions editors?

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