AOfficials from around the world gathered in Brazil for the 30th Climate Summit last month, and the President of the United States was nowhere to be found, nor were any of his Cabinet members. Instead, the most prominent American voice in Belem was that of California Governor Gavin Newsom.
During his five days in Brazil, Newsom called Donald Trump an “invasive species” and condemned his rollback of policies aimed at reducing emissions and expanding renewable energy. Newsom, long considered a presidential contender, claimed that as the United States backs down, California will advance its position as a “stable and 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 on nine out of 10 days in 2025. Outside of China, there is only one other jurisdiction in the world — California — that has the same amount of battery storage,” Newsom said.
The Golden State has transformed how its major electric grid is powered in recent years, setting ambitious goals for a net-zero emissions grid by 2045 and investing heavily in solar, wind and battery storage. As the federal government abandons climate initiatives, California appears poised to play an increasingly important global role.
It seems the country has a lot to celebrate. Since 2019, the state has added 30,800 megawatts of clean energy and battery storage. While natural gas is still the state’s primary energy source, it is declining: Saw ca The largest year-over-year decline in natural gas production this year.
Meanwhile, solar and batteries, which allow energy to be stored for later use and provide an alternative to gas, are moving in to replace it, said Mark Jacobson, a Stanford University professor and renewable energy expert. “This is a remarkable shift.”
“Leader in clean energy”
When touting his accomplishments as governor, Newsom has frequently referenced the California network. State lawmakers in 2018 passed a invoice Requires California to generate 60% of its electricity from renewable, carbon-free sources by 2030 and 100% by 2045.
So far, California appears to be on the right track, Jacobson said. Clean energy accounted for 67% of retail electricity sales in 2023, according to most estimates Recently available data. For the first time, clean energy — which the state recognizes as renewable energy sources such as solar, wind, small hydro, geothermal and biomass, as well as large hydroelectric and nuclear — provided 100% of power to the state’s main grid nearly every day for at least some of the day in 2025.
Renewable energy sources are booming around the world and are expected to grow more rapidly than any major energy source over the next 10 years with more projects in the next five years than in the past 40 years, according to the International Energy Agency (IEA).
California is no exception, and is in the midst of what the state Energy Commission (CEC) has described as “the largest transformation of its electricity grid in a century.” The state is seeing new solar and battery storage projects in “record numbers” and is expected to soon completely remove coal from its energy supply, according to the CEC.
Key to this growth has been the expansion of battery storage, a critical tool for retaining energy produced from renewable sources. In 2019, California had 771 megawatts, and by October of this year, it had nearly 17,000 megawatts. The state has 2.5 times more battery storage capacity than it had in 2022.
The batteries helped the state avoid rolling blackouts and allowed the California Independent System Operator (Caiso), a nonprofit that manages the flow of electricity on the state’s main grid, to store solar power when there is a surplus during the day.
“Then we can use that stored energy and release it in the evening hours when the sun goes down,” said Mark Rothleder, Caiso’s senior vice president and chief operating officer. “Having a mix of resources capable of producing when needed is an important plus as we try to make this transition to renewable resources.”
But he said solar and wind are intermittent resources, meaning they can only be generated when there is sun or wind, and the state’s main grid continues to rely on gas resources that can be tapped as needed.
Natural gas was the largest single resource for electricity production in 2024, but natural gas generation declined 8% that year, due in part to the increasing role of solar and wind power and the promotion of battery storage, according to the CEC.
Nuclear power also plays a role — in 2024, it accounted for nearly 10% of the state’s total electricity generation — though it’s not without controversy. California has been a center of anti-nuclear activism for decades, but supporters say it could be a crucial tool for providing reliable energy as the state transitions away from fossil fuels.
Although natural gas may be in decline, it is by no means obsolete — and is relied upon as an important backup during times of peak energy use. California has nearly 200 natural gas plants that provide energy Nearly a third of the country generating electricity, said Julia Doyle, a senior campaign organizer with the Sierra Club.
“California is seen as a leader in clean energy,” Doyle said. “But we’re really struggling to figure out how to meet demand in those evening hours when we see the greatest demand for electricity, and that’s historically when we’ve relied on gas plants.”
A 2025 report from Regenerate California, which Doyle helped write, found that batteries are a less expensive and more reliable alternative to gas plants, and reduce toxic air pollution.
“They can compete directly with gas plants, and they can provide more benefits because of their ability to ramp up production so quickly,” said Hina Singh, of the California Environmental Justice Coalition and author of the report. “This is a big thing in California, where we have all these heat waves and natural disasters.”
Confronting the Trump administration
California has long been a frequent target of the Trump White House — and the conflict has intensified during his second term.
With Trump back in power, the federal government has focused on expanding the use of fossil fuels and seemingly blocking any effort to reduce emissions. The White House has proposed offshore lease sales along the California coast. The president blocked California’s first law banning the sale of new gas-powered cars by 2030, and his Environmental Protection Agency ended a $7 billion program to bring solar power to low-income communities.
The administration has cut $679 million in funding for offshore wind projects across the United States — and California was expected to see about $427 million for a project to build its first offshore wind farm on the West Coast. Months ago, California and nearly 20 other states Successfully A lawsuit was filed after the federal government moved to temporarily stop offshore wind development.
More lawsuits are expected. The state Attorney General’s Office created a dedicated office to respond to the president’s agenda.
Republicans and the Trump administration have also sought to blame the transition to renewable energy for rising 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 customers.
Despite these pressures, California’s energy transition is well underway – and is unlikely to reverse course.
“You’ll see California aggressively suing every effort by the federal government to roll back the fight against climate change and the fight against clean energy,” said Noah Burch-Ahern, an environmental attorney. “I think this will continue for years.”
Meanwhile, advocates and experts hope to see California continue to expand clean energy through more rooftop solar projects that can reduce demand on the grid, and eventually phase out gas plants.
“We really hope that people start to realize that we don’t need these gas plants,” said Maya Leroy, author of the Regenerate report, adding that there are significant costs to keeping them running even when the state is not using them to generate power. “It’s time to shut it down. It’s an expensive insurance policy.”
She hopes California can keep moving forward despite the federal hurdles.
“We made it through the first Trump administration,” she said. “California survived, and we never backed down on any of our clean energy goals. So I don’t expect that to become an issue again this semester.”