Hot, dry summers have brought problems to California’s power grid in recent years. Utility customers in San Diego County and across the state experienced repeated power outages in August 2020 and narrowly avoided repeated power outages in 2021 and 2022.
But power industry and electric system officials say the outlook for this summer is much brighter, thanks to a potential increase in hydroelectric generation, in addition to thousands of megawatts of energy storage, thanks to all the rain and snow that fell in the Golden State. this winter.
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Shiva Gunda, vice chairman of the California Energy Commission, said at a press conference on Wednesday, May 24, that “I am relieved to say that we are in a much better position than last year”.
But he hastened to sound a note of caution: “Climate change extremes remain a wild card. Another extreme event like last summer could put the network into vulnerable territory.”
Triple-digit temperatures were recorded across the state in late August and early September 2022, prompting the California Independent System Operator—which manages the electrical system for about 80% of the state—to issue 10 consecutive days of flexible alerts inspired to do.
The grid operator, called CAISO, asked utility customers across the state to voluntarily reduce their power consumption for hours to avoid grid collapse. The demand reached a record 52,061 MW on 6 September.
This summer the figures are far more encouraging.
On 1 September, CAISO expects around 8,000 MW more new resources to be available than in September last year.
“We’re also cautiously optimistic,” says Neil Miller, CAISO’s vice president of infrastructure planning and operations.
More rain equals a better year for hydropower
What a difference a wet winter can make.
After a dozen atmospheric rivers passed through California between late 2022 and early 2023, reservoirs were short of water last year.
This means that nearby hydroelectric plants will be able to add much needed megawatts to the state’s power grid.
In April, CAISO saw a trend of record hydro conditions nearly 2.5 times above average, Miller said, “obviously putting us in a better position for the summer.”
The US Energy Information Administration is optimistic, predicting that hydroelectric power generation in California will be 72% higher this year than in 2022.
That combined with production from renewable energy sources like more hydro, solar and wind means the state won’t have to rely heavily on natural gas. In its near-term energy outlook released earlier this month, the Energy Information Administration predicted a 9% decrease in natural gas-fired electricity generation in California this year compared to last year.
However, if temperatures rise rapidly and the Sierra’s snow melts too rapidly, state officials may be forced to divert water for flood control instead of generating hydroelectricity.
But officials at the UC Berkeley Central Sierra Snow Lab, located at about 7,000 feet over Donner Pass in the Sierra Nevada, report snow melt continuing at a good rate leading up to Memorial Day weekend.
“In a normal year, our site would have completely melted by May 16,” said Andrew Schwartz, lead scientist at the Snow Lab, “but we have basically a whole year’s worth of meltwater.”
Officials with the California Department of Water Resources measure snowfall at Phillips Station in the Sierra Nevada mountains on April 3, 2023.
(Ken James/California Department of Water Resources)
What’s called “snow water equivalent” is an important measurement that refers to the total amount of water that is present in the snowpack and will leave when it evaporates. Schwartz said that as of Wednesday, the average snow water equivalent across the state was 313%.
The Snow Lab has been recording data since 1946 and this winter measured 754 inches of snow, making it the second snowiest on record. Only the winter season of 1951-52 had more (812 inches).
“It’s very rare that we have years like this,” Schwartz said.
The two biggest reservoirs of the state are full of water.
Shasta Lake, near Redding, feeds the Shasta Power Station, which produces hydroelectricity for the western 15-state power grid. As of Monday, May 22, Lake Shasta was at 117% average and 98% capacity, according to the Department of Water Resources.
And reservoir levels at Oroville Dam in the Sierra Nevada foothills that supply the Edward Hyatt power plant were 122% of average and 96% of their capacity on Monday.
This is a remarkable change for Auroville.
In August 2021, a prolonged heat and drought reduced water levels to record depths and the Hyatt Power Plant shut down for the first time since it began operating in 1967. After five months without production, the plant reopened in January 2022, but the flow was low.
A strong hydroelectric year gives California power grid managers a much-needed cushion.
In wet years, such as the winter of 2016–17, hydroelectric facilities can supply about 21% of all state production to the grid.
But in dry years the numbers can drop dramatically. In 2015, large and small hydroelectric power plants combined produced only 7.1% of the state’s output. Figures for 2022 are still being tabulated by the Electricity Commission, but in 2021, the state accounts for only 7.5% of hydro generation.
In addition, the abundance of hydroelectric power makes the state grid less dependent on imported megawatts from resources outside the state.
It also provides flexibility to power system managers during peak summer hours, especially between 4:00 pm and 9:00 pm. They are times when solar power is low as the sun goes down, but demand remains high as customers keep their air conditioners on until temperatures cool.
It is in these situations that flexible alerts are issued.
increase battery storage
Although the hydropower numbers are encouraging, the California Energy Commission’s Gunda said additional megawatts of energy storage will make the biggest difference this summer.
“We are in a much better position in terms of the number of resources we have to support the network,” Gunda said.
CAISO estimates an additional 3,000 MW of energy storage will be available this summer.
Energy storage—specifically from batteries—is considered vital for California to meet its goal of getting 100% of its electricity from carbon-free sources by 2045.
Although renewable sources such as solar and wind are a major source of the state’s energy mix, they are intermittent: solar can be abundant when the sun is shining but disappear at night, and when the wind If it is not running, the production of wind farms ceases. , Storage can help fill in those gaps.
The batteries can absorb solar power generated during the day and discharge power later, especially in the critical period of 4-9 p.m., when California’s grid is under the most stress.
The California Public Utilities Commission has directed the state’s power companies to contribute 18,800 MW of new generation capacity by 2028, making it the largest clean energy resource need in the state’s history.
But all of that has a cost. The cost of obtaining these energy sources is included in the rates paid by utility customers, and rising electricity bills have raised questions about their affordability.
In fact, the CPUC released a 131-page report last year that projected increases in electric bills for customers of the Big Three investor-owned utilities. It is projected that between the first quarter of 2022 and the end of 2025, San Diego Gas & Electric’s rates will increase by 24%, Pacific Gas & Electric’s by 26%, and Southern California Edison’s by 16%.
Alice Reynolds, CPUC chair, said the commission’s integrated resource planning process is designed to help ensure that companies selling energy resources and utilities that buy them bid on competitive contracts that are efficient.
“It’s a way to meet the needs of the future generation in the least expensive way possible, while making sure we do everything possible to advance clean energy and keep prices down,” Reynolds said. “
While the outlook for the summer is good, Reynolds cautioned that doesn’t mean flex alerts won’t be issued if conditions worsen.
“This is unlikely to happen, especially given the increased temperatures in recent years,” Reynolds said.
good news about wildfires
Wildfires can knock down power lines and knock out megawatts of power.
For example, in July 2021, bootleg fires in Oregon disrupted a major transmission line called the California-Oregon Intertie, which carries imported electricity from the Pacific Northwest to California.
The Bootleg Fire burned over 476 square miles in July 2021.
(associated Press)
If a similar wildfire threatens a major transmission line this summer, “the state may face an additional 3,000 to 4,000 MW of resource loss,” Gunda said.
Additionally, heavy smoke from wildfires can cloud the sky and reduce solar generation from the grid.
Fortunately, wet weather has greatly reduced the number of fires so far this year. Cal Fire reports that, as of May 22, it has responded to or assisted with 985 calls for wildfires that have burned a combined 1,024 acres across the state.
At the same time last year, the Cal Fire responded to more than double the calls (2,122 to be exact) burning almost nine times as much area (9,567) than it did this year.
But Robert Carvalho, chief of the Cal Fire Communications Battalion, cautioned that what got off to a great start to 2017 is likely to come to an end in the coming months.
“There was significant rain in the early part of the year, but then high winds created a highly destructive fire season with more than 1.5 million acres burning in 2017,” Carvalho said. “So there’s no guarantee.”
What is the long term expectation beyond this summer?
Snow lab Sierra’s Schwartz says back-to-back abundant snow is rare. The winters of 1981–82 and 1982–83 were the last times this happened.
“It happens,” Schwartz said, “but it’s very unlikely.”
