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Low water levels could force Oroville hydropower to disconnect

A major hydroelectric plant in California may soon stop producing electricity amid a worsening drought.

State water officials say the Edward Hyatt Lake Oroville power plant could be shut down as early as August or September – a time that would coincide with a dreaded energy crisis this summer. The factory, which opened in the late 1960s, has never been forced to disconnect by the low level of the lake before.

“I think it’s a little shocking,” said Jordan Kern, professor in the department of forest and environmental resources at North Carolina State University. “The fact that it is scheduled to go offline shows just how severe the drought is,” said Kern, who studies the impact of power grids on extreme weather conditions.

California Energy Commission spokeswoman Lindsay Buckley said the commission is actively planning to take the plant offline this summer. But the Hyatt power station is far from the only source of hydroelectric power in the state that will likely be affected by extreme weather conditions in California.

On July 1, the commission, along with the California Independent System Operator, or California ISO, and the California Public Utilities Commission, released a letter regarding the expected drought hydropower losses this year, which occur against a backdrop of history of climate change. heat events caused. According to the letter, drought conditions reduced the state’s hydropower capacity by about 1,000 megawatts.

The Hyatt power plant is designed to produce up to 750 megawatts of electricity, but typically produces between 100 and 400 megawatts, depending on the level of the lake. According to Buckley, the high average demand per day in the state is typically around 44,000 megawatts, so 400 megawatts would be just under 1% of that total.

“It’s not necessarily the tipping point,” Buckley said. “There are a lot of different factors that challenge the overall reliability of the grid this summer. And Hyatt is part of the story.

For decades, outlets from Lake Oroville – California’s second largest reservoir – have generated electricity that powers the state grid. Located in the western foothills of the Sierra Nevada, the Oroville Dam complex includes the eponymous dam and three power plants that work together to pump and store water and generate hydroelectric power. The facilities are also used for flood management, improving water quality, and serving fish and wildlife. The complex is a key part of the State Water Project, a 700-mile system of aqueducts, reservoirs and pumping stations that stores and distributes water to urban and agricultural users in northern California, Bay of San Francisco, the San Joaquin Valley and Southern California. California.

Water from the Feather River, heavily affected by precipitation and snowmelt, feeds the Oroville complex. The dam discharges water into the Feather River, which flows downstream into the Sacramento River and ultimately into the California Delta.

Like many things in California, the recent woes at Lake Oroville have been a story of extremes. In 2017, millions of gallons of water eroded the dam’s main and emergency spillways, forcing the evacuation of thousands of residents. The 2016-17 rainy season was one of the wettest in California history, bringing more water to Lake Oroville than the reservoir could hold, which was one of the many factors that affected Lake Oroville. led to the 2017 crisis.

Just four and a half years later, fortunes on the shores of the lake are very different. Aerial photos of the reservoir – a key stock in California’s water supply and a popular recreation destination – have become a symbol of the current drought, with barges eclipsed by steep banks and boat launching ramps that stop well above the waterline. Lake Oroville is currently 661 feet above sea level with 982,000 acres of storage, which is 28% of its total capacity and 36% of its historical average, according to the California Department of Water Resources.

“Hyatt Powerplant is unable to generate electricity once the lake elevation drops below approximately 630-640 feet due to lack of sufficient water to run the hydroelectric turbines at the plant. “said John Yarbrough, deputy assistant director of the State Water Project in the California Department. of the water resource. “This would be the first time Hyatt has lost production capacity due to low lake elevation,” he said in an emailed statement.

In 1977, during what was then the worst drought on record in California, the power plant generated minimal electricity but remained on-line. The plant also remained online in 2014 and 2015, during what is now considered the worst drought in state history.

But according to the California Department of Water Resources, Lake Oroville received only about 20% of the expected runoff from snowmelt this year, which the DWR called a record low level.

If the plant stops producing electricity, it will likely go offline for months. “The resumption of power generation would depend on returning lake levels to elevations that allow us to run the plant,” Yarbrough said.

It would take a crystal ball to give an exact date, but since the reservoir is fed by runoff from the Feather River, it could be well in November or early December before enough precipitation arrives in California to reignite the underground turbines. .

The additional energy to offset the state’s reduced hydropower supply this summer will come from other energy sources, according to California ISO, the entity that oversees the flow of electric power through most of the world. ‘State. “It could come from several other shippable resources within ISO, natural gas being the largest category of these, or from any number of resource types outside ISO that bid as. than imports, “said Anne Gonzales, spokesperson for ISO in California.

Generally speaking, a drought affects the energy system in two main ways. There is less surface water, with less water flowing in streams and rivers, and less electricity that can be produced from hydroelectric sources like the Hyatt power station. Drier years also tend to be warmer years. This extreme heat not only worsens the drought, but also means that demand for electricity can skyrocket as millions of people turn on air conditioning to avoid the heat.

“The general message has been that climate change is impacting a number of our systems. Electricity is one of them. We’re asking consumers to be aware this summer, ”Buckley said, urging Californians to sign up to receive Flex Alerts this summer so they can help conserve energy during times of stress on the grid.

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