California, the tech solution to save yourself from blackouts

In California, where there has been a particularly intense heat wave in recent weeks, those around sunset are problematic hours. In the offices of the Independent System Operator (ISO) of California, which manages the state’s electricity grid, the situation becomes tense. The body’s mission is to ensure that the electrons reach their destination, to avoid blackouts that could affect millions of people.

The risk is due to a short, but important, imbalance between supply and demand. A growing share of the state’s energy comes from solar panels, which accounted for about a fifth of supply last year. When the sun goes down and the panels stop receiving photons, however, the demand for electricity continues to rise. People come home from work, charge their electric cars, and turn on the air conditioning to eliminate the afternoon heat. Maybe they make dinner and start the dishwasher. Meanwhile, at work, the lights in the offices are supposedly still buzzing.

The role of batteries

These were the main concerns during last week’s heat emergency when dozens of Californian cities broke historical temperature records and the demand for energy has soared. This time around, however, the California ISO had additional energy at its disposal: a relatively new fleet of batteries designed to hold power for about four hours, the time needed to cover the evening deficit. At peak production, around 6 percent of energy supply today comes from these batteries, up from 0.1 percent in 2017, according to an analysis of Bloomberg. In the last year, the energy capacity has almost doubled. Shortly after 6pm on Tuesday, September 6, the batteries outpaced production from the last remaining nuclear power plant in California, reaching just under 3,000 megawatts.

A second aid also came to the aid of the Californian network, this time on the demand side. Around 5:45 pm, the phones of millions of Californians received a message inviting them to postpone evening activities to save energy. Apparently, the appeal was heard. According to Anne Gonzales, spokesperson for California Iso, over the next 20 minutes, more than two thousand megawatts of demand disappeared from the grid. It happened so quickly that many energy experts were amazed: “I was pleasantly surprised to see how everyone joined forces“says Ryan Hanna, an energy researcher at the University of California, San Diego.

Overall, according to Hanna, the use of batteries and SMS alerts are relatively factors. “marginal“to maintain a balance between supply and demand, given the peak demand recorded in California last week (52,000 megawatts). In the evening, the state still relies on natural gas (which reached a peak of nearly 27,000 megawatts). ) to complete the supply of electricity, as well as imports from other states. Despite the fact that on September 6 in the San Francisco metropolitan area there were rotating interruptions to supplies affecting about 50 thousand users – due to what the California Iso has then defined a communication error – it was a much lower number than expected. In the two following days, despite a question close to the record hit on 6 September, blackouts were again avoided.

Difficulty in implementation

In California, the deployment of batteries to supplement the electricity grid has been relatively slow. Initiatives to restructure the grid and create more batteries began ten years ago, but lagging behind in terms of actual installations compared to renewable energies such as wind and solar farms. In part, this is because batteries are a puzzle from a regulatory point of view. Determining what the right incentives are for an energy source that stores energy instead of producing it is complicated. Also, while solar panels and wind turbines are now ubiquitous in the state, grid operators are less experienced in battery use. California’s largest battery, a 1600 mw-hour facility housed in a natural gas power plant in Moss Landing, has been mostly inactive for nearly a year due to temperature management issues of large ion battery stacks of lithium.

There are also other problems to be solved. Earlier last week, some batteries they started putting in energy earlier than expected, when the price paid to battery operators for their energy has exceeded the limit imposed by the state. Having no advantage in holding back their electrons longer, the batteries began pumping in energy well before the grid was on high alert. According to Dan Kammen, an energy expert at the University of California, Berkeley, the analysis needed to determine if this was the right move. “it has to come yetHowever, a debate is likely to arise on the right way to incentivize the functioning of the batteries and, potentially, to redesign the software that controls their functioning to make it more flexible in extreme situations.

Over the past couple of years, the difference in battery usage in the early evening hours has been noticeable, with a more than 10-fold increase during peak usage in 2022 compared to 2020. State plans call for an increase to 41 gigawatts of battery power by 2045, up from around 3 gigawatts today.

Margin of improvement

And that’s good, Kammen points out, since in some respects for most of this heat wave California was lucky. If on the one hand the heat was extremely intense, in fact, on the other there were no strong winds, which would have risked creating problems with the power lines and starting fires, leading the electricity companies to cut off the current in advance to avoid inconvenience. Worse still, wildfires can force other parts of the system to shut down or generate smoke that can obscure the sun and reduce solar production (exactly what happened on the evening of September 8, at the end of the heat wave, in Southern California, California. prompting the authorities to issue a request to reduce demand from the early hours of the day). The predominantly mild weather conditions in the following days allowed grid operators to use most of the tools at their disposal. In addition, hundreds of thousands of homes and businesses have fed electricity into the system thanks to solar panels installed on their roofs, reducing the pressure on the grid. Solar power generated by the rooftop panels provided an impressive 8,000 megawatts during Tuesday’s peak.