AOfficials from around the world met in Brazil for the Cop30 climate summit last month, but the US president was nowhere to be seen, nor were members of his cabinet. Instead, the most prominent American voice in Belen was that of the Governor of California, Gavin Newsome.
During his five days in Brazil, Newsom described Donald Trump as “invasive speciesNewsom, long considered a presidential candidate, argued that as the U.S. retreats, California will take its place as a “stable, reliable” climate leader and partner.
Among the talking points he used to demonstrate California's leadership was its progress in renewable energy — and the battery capacity needed to store that energy.
“We run the fourth largest economy in the world” [on] 67%, two-thirds, clean energy for nine out of 10 days in 2025,” Newsom said. “With the exception of China, there is only one jurisdiction in the world—California—that has deployed the same amount of battery storage.”
In recent years, the Golden State has changed the way it supplies electricity to its main grid, setting ambitious goals for a zero-emissions grid by 2045 and investing heavily in solar, wind and battery storage. And as the federal government retreats from climate initiatives, California appears poised to take on an increasingly important global role.
Looks like the state has a lot to celebrate. Since 2019, the state has added 30,800 megawatts of clean energy and battery storage. And while natural gas is still the state's primary source of energy, its quantity is declining: California saw This year saw the largest drop in natural gas production in history.
Meanwhile, solar panels and batteries, which can store energy for later use as an alternative to gas, are increasingly replacing it, said Mark Jacobson, a Stanford professor and renewable energy expert: “It's a remarkable shift.”
“Leader in Clean Energy”
In touting his accomplishments as governor, Newsom often referenced California's power grid. State legislators passed in 2018 check requiring California to produce 60% of its electricity from renewable, zero-carbon sources by 2030 and 100% by 2045.
So far, California appears to be on the right track, Jacobson said. According to the majority recently available data. For the first time in 2025, clean energy, which the state recognizes as renewable energy sources such as solar, wind, small hydro, geothermal and biomass, as well as large hydro and nuclear, provided 100% of the state's main grid power almost every day for at least some part of the day.
Renewable Energy thriving all over the world It is expected to grow faster than any major energy source over the next 10 years, with more projects underway in the next five years than in the last 40 years, according to the International Energy Agency (IEA).
California is no exception and is in the midst of what the state's Energy Commission (CEC) has called “the largest grid transformation in a century.” The state is considering new solar and battery projects in “record numbers” and is expected to soon eliminate coal from its energy supply entirely, according to the CEC.
Key to this growth has been the expansion of battery storage, a critical tool for storing energy produced from renewable sources. California had 771 megawatts in 2019, and nearly 17,000 by October of this year. The state has 2.5 times more batteries than in 2022.
The batteries helped the state avoid rolling blackouts and allowed the California Independent System Operator (Caiso), the nonprofit that manages the flow of power on the state's main grid, to store solar energy when there was excess power during the day.
“Then we can take that stored energy and release it in the evening hours when the sun goes down,” said Mark Roethleder, Caiso's senior vice president and chief operating officer. “Having a mix of resources that can produce when needed is an important addition as we try to make the transition to renewable resources.”
But he said solar and wind are intermittent sources, meaning they can only be generated when there is sun or wind, and the state's primary power grid continues to rely on gas resources that can be used as needed.
Natural gas was the largest resource for electricity generation in 2024, but natural gas output fell 8% this year, in part due to the growing role of solar and wind power and increasing battery capacity, according to the CEC.
Nuclear power also plays a role—accounting for nearly 10% of the state's total electricity production in 2024—though not without controversy. California has been a center of antinuclear activism for decades, but advocates say it could be a critical tool for ensuring reliable energy supplies as the state transitions away from fossil fuels.
While natural gas supplies may be dwindling, they are far from obsolete—and are relied upon as a critical reserve during periods of peak energy demand. California has approximately 200 natural gas plants that provide about a third of the state Electricity generation, said Julia Dowell, senior campaign organizer for the Sierra Club.
“California is considered a leader in clean energy,” Dowell said. “But we're really struggling to figure out how to meet demand during those evening hours when we see the greatest need for electricity, and that's when we've historically relied on gas-fired power plants.”
The Regenerate California 2025 report, which Dowell helped author, found that batteries are a less expensive and more reliable alternative to gas plants and also reduce toxic air pollution.
“They can compete directly with natural gas plants and could provide even more benefits because of their ability to scale up so quickly,” said Hina Singh of the California Environmental Justice Alliance and an author of the report. “This is important for California, where we have all these heat waves and natural disasters.”
Fight back from the Trump administration
California has long been a frequent target of the Trump White House, and the divisions have only intensified during his second term.
Since Trump's return to office, the federal government has focused on expanding the use of fossil fuels and curbing seemingly any efforts to reduce emissions. The White House has proposed selling offshore properties along the California coast for lease. The president blocked California's first rule that would ban the sale of new gasoline-powered vehicles by 2030, and his Environmental Protection Agency ended a $7 billion program to provide solar energy to low-income communities.
The administration has canceled $679 million in funding for the development of offshore wind farms across the United States. California was expected to receive about $427 million for the project to build the first offshore wind terminal on the West Coast. A few months earlier, California and nearly 20 other states successfully sued after the federal government decided to halt offshore wind development.
More trials are expected. The state Attorney General's Office has created a department designed to counter the president's plans.
Republicans and Trump administration They have also tried to blame the transition to renewable energy for high utility bills—California has some of the most expensive bills in the country. But experts attribute these costs to energy companies passing on the costs of wildfires to consumers.
Despite these pressures, California's energy transition is well underway—and it's unlikely to change course.
“You'll see California vehemently challenging every effort by the federal government to roll back the fight against climate change and the fight against clean energy,” said Noah Perch-Ahern, an environmental lawyer. “I think this will continue for many years.”
Meanwhile, advocates and experts hope California will continue to expand clean energy with more rooftop solar projects that could reduce demand on the grid and eventually phase out gas-fired power plants.
“We're just really hoping that people will start to understand that we don't need these gas plants,” said Maya LeRoy, author of the Regenerate report, adding that keeping them running is a significant cost even if the state doesn't use them to generate electricity. “It's time to close them down. It's expensive insurance.”
She hopes California will continue to move forward despite federal obstacles.
“We made it through the first Trump administration. California survived, and we never backed down from any of our clean energy goals. And so I don't foresee this being an issue again this year,” she said.
