Explanations come to light
According to report, combination of factors caused California's rolling blackouts in August
A report from three key state groups analyzing what caused a pair of blackouts in mid-August largely conformed to reasons previously cited by California's grid operator — that a combination of factors, including a sweltering heatwave, pushed the state's power system to its edge, leading to the first statewide outages in nearly 20 years.
“The extreme heat storm in August was an extraordinary 1-in-35-year event that, with climate change, is unfortunately becoming more common,” Marybel Batjer, president of the California Public Utilities Commission, said in a statement.
After two straight days of rotating outages on Aug. 14 and 15, Gov. Gavin Newsom ordered the utilities commission, the California Energy Commission and the California Independent System Operator to deliver a preliminary root- cause analysis.
The system operator, a nonprofit known as the CAISO for short, manages the electric grid for about 80% of California. The energy commission's duties include advancing California's energy policy while the public utilities commission's job includes setting reliability requirements.
On Aug. 14, 491,600 electricity customers of California's three big investor-owned utilities — San Diego Gas & Electric, Southern California Edison and Pacific Gas & Electric — lost power between 6:30 p.m. and 7 p.m. for anywhere between 15 minutes to 2 1/2 hours.
The next evening 321,000 customers statewide were cut off, with downtimes ranging from eight to 90 minutes.
If not for emergency measures that brought in extra energy sources and everyday consumers consciously reducing their electricity demand, there would have been more blackouts Aug. 17- 19. Another heatwave over the Labor Day weekend nearly led to the CAISO initiating other rounds of rotating outages.
The rolling blackouts in August were the first in the state since the California energy crisis in 2001, which led to the ousting of then-Gov. Gray Davis.
The 121- page report released Tuesday said there was “no single root cause of the outages, but rather, a series of factors that all contributed to the emergency.”
A stubborn heatwave led to California experiencing four of the five hottest August days since 1985. Death Valley recorded a 130-degree high on Aug. 16. The heat led to customers across the state to crank up their air conditioners, putting demand on the grid.
In addition, extreme heat caused some power sources such as natural gas plants to run less efficiently, reducing output.
Normally, California imports power from neighboring states to help make up the difference but the August “heat storm” also settled over states across the West and they held on to their resources instead of sending them to the Golden State. In addition, the report said a major transmission line in the Pacific Northwest was down due to weather.
If it's not as hot in the early evening as it is in the afternoon, why did the blackouts on Aug. 14 and 15 occur at that time?