Officials are crossing their fingers that hydropower will have a good year, assisting power grid operators, due to rising reservoirs and a deep snowpack.
There has been a lot of suffering brought on by the recent torrential rains in California, but there may also be some good news regarding the energy sector: if rain and snow totals hold, all the precipitation will increase hydroelectric production, which will benefit the Golden State’s electric grid, particularly during the summer when the system is under stress.
“Based on the reservoir levels and what we’re seeing this year, we expect to have more hydroelectricity generated this year than we have for the last several years,” said The California Energy Commission’s spokesperson is Lindsay Buckley.
The Shasta Powerplant, which generates hydroelectric power for the 15-state Western power grid, is fed by Shasta Lake, California’s largest reservoir, which is located close to Redding. The Department of Water Resources reports that Shasta Lake was at 83% of average as of midnight on Monday.
The reservoir levels at the Edward Hyatt Power Plant’s Oroville Dam, located in the Sierra Nevada foothills, are up to 104% above average. Near Sacramento, the Folsom Dam has inflated to 123% of its normal size.
The Sierra’s snowpack is rapidly increasing as well.
At Donner Pass, at a height of almost 7,000 feet, the UC Berkeley Central Sierra Snow Lab reported accumulating 80.9 inches of snow in the previous week.
Melting snow in springtime feeds the rivers that help power large hydro facilities, and “snow water equivalent” is a crucial metric. This phrase describes the total volume of water that the snowpack holds and that it will release when it evaporates.
As of Tuesday morning, the Snow Lab’s measurement of snow water equivalent was 35.6 inches as opposed to an average year’s 17.2 inches. This represents 207% of the average for the current water year, which runs from October to September. 1, 2022, to Sept. 30, 2023.
“That means we [have] just about twice the amount of water in the snowpack that we would expect [at] this point in that water year,” said Lead researcher at the Snow Lab, Andrew Schwartz.
Snow water equivalent has already reached an average peak of 96%.
“We typically hit our peak snowpack depth in water equivalent at the end of March, and we’re already nearly at what that peak normally looks like,” Schwartz said. “Therefore, we are approaching our normal peak in snow water equivalent about two and a half months earlier than usual.”
Grid operators in California may benefit greatly from a good hydro year.
Natural gas generation is increased to help make up the difference when there are hydropower shortages, which raises greenhouse gas emissions.
Grid operators may be slightly less dependent on electricity from out-of-state sources if there is a surplus of hydropower.
Additionally, it gives power system managers more flexibility during summertime peak hours like from 4 to 9 p.m. During those times, solar generation decreases as the sun sets, but demand is still high because people are running their air conditioners until the temperature drops.
The California Independent System Operator last summer issued 10 days of Flex Alerts in a row asking utility customers to voluntarily reduce their energy use due to a stressed grid.
Hydro facilities are capable of supplying the grid with about 21% of all in-state generation during wet years like 2016–17.
But the numbers can drastically decrease in dry years. Just 7.1% of the state’s generation was generated in 2015 by large- and small-scale hydro. The energy commission is still compiling data for 2022, but in 2021, hydro made up a pitiful 7.5% of in-state generation.
When conducting their assessment for the summer of 2023 in May, officials at the California ISO, which oversees the electric grid for about 80% of the state, will decide whether to make any hydroelectricity output projections.
“Even though we’ve received lots of rain so far, we don’t know what the rest of the season will be,” Anne Gonzales, a spokesperson for the California ISO, said.
The Snow Lab recorded record snowfall amounts in December 2021, giving the previous winter a great start. But Mother Nature suddenly closed the faucet. The longest time without any winter precipitation ever recorded in the lab’s records, which date back to 1970, was the 37 days in January and February 2022 when there was absolutely no snowfall.
The year 2022 will go down as yet another year of drought because neither Northern nor Southern California received much rain.
“That is so fresh in the back of water modelers’ and managers’ minds right now that we’re a little bit hesitant to start celebrating this amazing snowpack because there is a slim chance that we might see that happen again this year,” Schwartz said.
The California Department of Water Resources’ John Yarbrough, assistant deputy director of the State Water Project, echoed this sentiment.
“Though early-season precipitation is encouraging, it’s prudent to remain diligent with the water conservation,” Posted in an email by Yarbrough. “The rainy season in our area is still ongoing, and it may turn dry as it did the year before.”
The Department of Water Resources and the U.S. Bureau of Reclamation both run sizable hydroelectric facilities in California, including Oroville, Folsom, and Shasta.
On Wednesday through Thursday, another storm is anticipated to pass through Northern California and the Sierra. The Snow Lab officials predict that the storm will drop an additional one to two feet of snow.