California Smashes Myth That Renewables Aren’t Reliable

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One of the biggest myths about renewables is that they aren’t reliable because the sun doesn’t always shine and the wind doesn’t always blow. Most people are blissfully unaware that while the sun is shining and the wind is blowing, a lot of the electricity they generate is stored in batteries. It’s called time shifting — generate electricity at 1 pm and use it at 8 pm after the sun sets. The normal way to make electricity since Thomas Edison and George Westinghouse had their DC versus AC tug of war over a century ago has been by spinning turbines either directly using diesel engines or indirectly by using steam created by burning stuff such as coal, oil, or methane. Nuclear reactors can also be used to make steam.

Electricity really doesn’t care how it is made, but it has one characteristic that makes it unique. It has to be used almost as soon as it is created. Otherwise, it is wasted. The problem for utility companies is that the demand for electricity varies during a normal day. Usually, there is very low demand overnight but things start ramping up in the morning and reach a peak in the middle of the day. There is typically an increase in demand in the late afternoon and early evening before things flatten out again after 10 pm. Managing the fluctuations in demand is a full time job. Nuclear and coal generating stations are not able to ramp up their output quickly. Only methane fired facilities can do that. That is why they are often called “peaker plants,” because they are pressed into service only at times of peak demand.

Energy Storage For Renewables

There are many types of electrical storage systems. Pumped hydro is one. Compressed air or carbon dioxide is another. In the past ten years, large grid scale battery installations have supplied much of the electrical storage capability, especially in California. Now a new study in the journal Renewable Energy co-authored by Mark Jacobson, professor of civil and environmental engineering at Stanford, demonstrates just how reliable the future of energy can be, based on an examination of electricity usage and supply in California.

The study found that last year, from late winter to early summer, renewables fulfilled 100 percent of the state’s electricity demand for up to 10 hours on 98 of 116 days. That’s a renewable energy record for California, but more importantly, blackouts during that time were virtually nonexistent, thanks in part to backup battery power. At their peak, the renewables provided up to 162 percent of the grid’s needs, meaning there was extra electricity available that could be exported to neighboring states or used to charge batteries.

“This study really finds that we can keep the grid stable with more and more renewables,” Jacobson told Grist recently. “Every major renewable — geothermal, hydro, wind, solar in particular, even offshore wind — is lower cost than fossil fuels” on average, globally.

High Utility Prices In California

Californians pay the second highest rates for electricity in the country. That’s not because of renewables, but largely because utilities’ electrical equipment has set off wildfires — like the Camp Fire started by Pacific Gas & Electric’s power lines, which devastated the town of Paradise and killed 85 people. Now the utilities are passing the costs resulting from those lawsuits and the costs of burying transmission lines onto their customers. While investigators don’t know for sure what sparked all of the wildfires that have ravaged Los Angeles this month, they will be scrutinizing electrical equipment in the area. Power lines are especially prone to failing in high winds, like the 100 mph gusts that turned these Southern California fires into monsters.

Even with the incessant challenge of wildfires, California utilities are rapidly shifting to clean energy, with about half of the state’s power generated by renewables like hydro, wind, and solar. The study compared 116 days in 2024 to the same period in 2023 and discovered California’s output from solar was 31 percent higher and wind 8 percent higher. After increasing more than 30 fold between 2020 and 2023, the state’s battery capacity doubled again between 2023 and 2024, and is now equivalent to the output of more than four nuclear power plants. The study also found that renewables and storage allowed generating stations in California to burn 40 percent less fossil fuel than the year before. That’s an important statistic if you are keeping track of carbon emissions from generating electricity.

Grid scale batteries help grid operators be more flexible in meeting demand for electricity, which tends to peak when people return home in the early evening and switch on appliances like air conditioners just when the grid is losing solar power. “Now we’re seeing the batteries get charged up in the middle of the day, and then meet the portion of the demand in the evening, especially during those hot summer days,” said Mark Rothleder, chief operating officer of the California Independent System Operator, the nonprofit that runs the state’s grid.

Another pervasive myth about renewables is that they won’t be able to support more electric vehicles, induction stoves, and heat pumps plugging into the grid. How odd that people rend their garments in despair about the “threat” to the grid posed by electric cars but celebrate the huge spike in demand to power data centers and AI. Here again, California destroys the myth. Between 2023 and 2024, demand on the state’s grid during the study period actually dropped by about 1 percent. That’s partly because some customers installed their own solar panels, which reduced the amount of power drawn from the grid. In 2016, almost none of those customers had batteries to store that solar power to use at night. But battery adoption rose each of the following years, reaching 13 percent of buildings installing solar in 2023, then skyrocketing to 38 percent last year. That further reduces demand on the grid because those customers can now use their own solar power at night.

The Economics Of Battery Storage

Batteries also help utilities get better returns on their investments in solar panels. A solar farm makes all its money selling electricity during the day. But if it has batteries attached to the farm, it can also provide energy in the evening, when electricity prices rise due to increased demand. “That evening battery contribution is very key to the economics working out well,” Jan Kleissl, director of the Center for Energy Research at the University of California, San Diego told Grist.

What about the fire at Moss Landing last week? That knocked out just 2 percent of the state’s energy storage capacity. A grid running fully on renewables will have a lot of redundancy built in. In addition to multiple battery storage installations, electric school buses and electric cars are beginning to send power back to the grid when a utility needs it. So called vehicle-to-grid (V2G) technology represents a potentially vast network of backup energy.

The more renewables on the grid, the lower the electricity prices for customers, according to the new study. From October 1, 2023, to September 30, 2024, South Dakota, Montana, and Iowa provided 110 percent, 87 percent, and 79 percent, respectively, of their electricity demand with renewables, particularly wind and hydro. That is the primary reason why they have some of the lowest electricity prices in the nation.

California got 47 percent of its power from renewables over the same period, yet wildfires and other factors have translated into higher electricity prices. The California Public Utilities Commission (CPUC), for instance, authorized its three largest utilities to collect $27 billion in wildfire prevention and insurance costs from ratepayers between 2019 and 2023. Climate change is making California ever more prone to burn — a growing challenge for utilities. But the state’s banner year for solar and batteries just undermined the notion that renewables aren’t reliable.