The result is that officials often have to forgo solar production while the sun is shining, just hours before peak customer demand in the late afternoon and evening. The same is happening to a lesser extent with wind power – and the problem is emerging in many other states as well.
“It all comes down to this problem, it’s not about how much energy we have, but when and where the energy is produced,” said James Bushnell, professor of economics at the University of California, Davis. “In particular the solar resources – it’s just in the wrong places and at the wrong times.”
Some solar operators accept the situation as the cost of doing business, because larger plants can absorb more sunlight later in the day even if they produce excessively during sunny hours. This can benefit consumers, who can see lower rates when solar energy is turned on, as it is generally a cheaper energy source than fossil fuels. Advocates of the system say some inefficiencies are to be expected as California begins the nation’s most ambitious transition to clean energy, and that eventually there must be enough battery storage to ensure that excess energy is not wasted.
But California’s solar and wind generation at this point is well ahead of storage capacity, and in some cases nowhere near proper transmission lines. It can be costly to build and make space for batteries and transmission lines, fueling skepticism from the fossil fuel industry about green energy.
The need not to lose excess power was emphasized during the record heat wave that ravaged California for 10 consecutive days earlier this month, breaking heat records as temperatures soared above 100 degrees. Energy demand soared as residents hid indoors and raised their air conditioners.
State officials have called for conservation and issued daily alerts advising Californians to limit their energy consumption from 4 p.m. to 9 p.m. and officials urged residents to set the thermostat at 78 degrees during those hours and stop charging cars or using large appliances.
Despite these efforts, on September 6, the country set a record for energy consumption – and Dangerously close to forcing a targeted power outage To protect the power grid, something that hasn’t happened in two years. State officials say they avoided a blackout that evening just by sending an urgent emergency text message to residents, who responded quickly to cut back on their energy use.
But just hours ago, California was awash with energy. Solar production was booming by mid-morning as the sun set on hundreds of solar panel stations across the state. By 10 a.m., California’s autonomous system operator, the manager of the state’s electric grid, was rejecting hundreds of megawatts of solar power — unable to use it right now, make room for it on the state’s crowded power grid or save it for later when consumer demand will peak. .
By 5 p.m., with massive consumer demand on the grid, officials had turned down more than 3,000 megawatts of solar power. Customer demand was high, but solar production fell as the evening fell, and officials could no longer access that excess solar power earlier in the day. However, officials were able to get through the day without a power outage by turning to other power sources and texting residents.
Some experts have noted that Extreme heat waves caused by climate change will become more frequentwhile one of the chosen solutions to climate change – renewable energy, especially solar energy – is not always there when we need it.
“The very technology that the state relies on to reduce carbon emissions, solar power, is down exactly when electricity demand is at its peak,” said Kyle Meng, co-director of the Climate and Energy Program at the University of California, Santa Barbara. Environmental Market Solutions Lab. “One of our main treatments for tackling climate change may also be making us more vulnerable to the effects of climate change.”
The practice of rejecting renewable power generation is called “downscaling,” and it has risen rapidly in California in recent years — before waning a bit last year — as the state pushes hard to add more renewables to its energy mix, according to the calculations of the U.S. Information Administration. energy. In 2020, the California autonomous system operator will cut about 1.5 million megawatt-hours, or 5 percent of its total solar energy production, according to the Energy Information Administration; Last year, the percentage was close to 4.2%.
“It helps stabilize the network to remove some of the oversupply out of the system,” Ann F. Gonzalez, chief public information officer for the independent system operator, explained via email. She added that during the heat wave, Californians were encouraged to pre-cool their homes during midday — allowing them to take advantage of cheap and plentiful solar energy during daylight hours and set thermostats higher at a later time.
However, grid operators had more solar energy in their hands than they could use.
“People are concerned when there will be any solar cutbacks, but the reality is we have too much renewables at some times and not enough at other times,” said Bushnell, of the University of California, Davis. “If we have enough storage capacity, we can absorb this surplus. … This is where everyone hopes.”
In fact, battery storage has been growing rapidly in California, including a massive facility in Northern California on the site of a former gas-and-electricity plant in the Pacific Ocean. Total capacity doubled last year and is expected to continue to grow rapidly, with the help of tax credits included in the recent federal inflation-control act. The batteries started working during the heat wave, and state officials praised their performance.
Industry experts predict that the amount of available storage – or other potential uses for excess energy – will eventually increase to the point where shrinkage occurs on a much smaller scale, or not at all. They noted that California is undergoing a rapid energy transition, moving from heavy reliance on fossil fuels including coal just a decade ago, to a grid that is supposed to consist of 100 percent clean energy by 2045. Built in real time, with inefficiencies and perverse incentives still to be settled.
“I think downsizing is something that is a key indicator of how to add more storage,” said Alex Morris, executive director of the California Energy Storage Alliance, an industry group. “In California, you’re seeing increasing amounts of storage each year sucking up and preparing themselves for additional energy.”
Another possible solution to renewable energy oversupply is a mass shift in consumer demand, so that residents use energy in the middle of the day rather than in the afternoon or night, said Severin Bornstein, faculty director at the Institute of Energy at the Haas School of Business at the University of Haas. University of California at Berkeley. This has been discussed by policy makers but requires the cooperation of utilities to redesign price structures.
In Texas, where wind power has shrunk by massive amounts, many of the same questions have been raised about the practice. Some question how the on-site excess energy can be used in wind or solar power plants, eliminating the need for transmission elsewhere. Bitcoin and mobile data mining labs have been put forward as potential candidates to absorb the excess power.