Something approaching a miracle has been taking place in California this spring. Beginning in early March, for some portion of almost every day, a combination of solar, wind, geothermal, and hydropower has been producing more than a hundred per cent of the state’s demand for electricity. Some afternoons, solar panels alone have produced more power than the state uses. And, at night, large utility-scale batteries that have been installed during the past few years are often the single largest source of supply to the grid—sending the excess power stored up during the afternoon back out to consumers across the state. It’s taken years of construction—and solid political leadership in Sacramento—to slowly build this wave, but all of a sudden it’s cresting into view. California has the fifth-largest economy in the world and, in the course of a few months, the state has proved that it’s possible to run a thriving modern economy on clean energy.
A good place to view this feat is from Mark Jacobson’s home—a light-filled two-story modernist house that he shares with his family at the end of a classic suburban cul-de-sac on the edge of the campus of Stanford University, where he is a professor of civil and environmental engineering. In part, that’s because the house is an energy-efficient showpiece; its solar panels produce more than enough energy to cover what he uses, though it is still tied to the grid. In the garage, there are two Teslas (including a 2009 Roadster with a license plate that reads “GHG Free”) and a pair of the company’s Powerwall batteries. The first place Jacobson shows you on a tour is the mechanical room, where an air exchanger recovers ninety-seven per cent of the heat from the stale air that it pushes out of the house. Next up is the kitchen, where an induction cooktop cuts energy use by sixty per cent compared with gas, even as it boils water twice as fast. He also showed me an app on his phone that monitors his usage of the power generated by solar panels on his roof every few seconds. “Yesterday, seventeen per cent of the generation from my rooftop went into the batteries in the garage,” he said. “I used eight per cent of it at home, and I sold seventy-nine per cent to the grid.”
But the real reason to go see Jacobson is that he said this transition could and would happen. Beginning with an article he co-wrote for Scientific American, in 2009, he’s been making the case for a-hundred-per-cent renewable energy. It’s not been easy—after he won a prize, from the National Academy of Sciences, for a 2015 paper laying out the vision, twenty-one energy researchers wrote an analysis for the academy’s magazine that accuses him of modelling errors and of making “implausible and inadequately supported assumptions.” So Jacobson can be excused for crowing a bit on social media this spring, if you define crowing as posting almost daily graphs of the renewable-energy surge.
“Last year, we reached one hundred per cent a few times,” he told me, as we sat in his living room. “But, this year, there’s been thirty-two-per-cent more solar output” as big new solar farms have come online, and “wind is up eleven per cent.” And demand for electricity from the grid has dropped three per cent—mostly because so many people have put solar panels on their roofs, so they, like Jacobson, can supply much of their own power. Renewable energy has reached an inflection point in California, where there’s enough installed capacity to begin to show its real muscle, a message that’s being heard across the country. From January to April, renewables accounted for ninety-nine per cent of new power added to America’s grid. “Tides have turned,” Jacobson tweeted last week. “Fossil gas, coal, and nuclear are quickly becoming the ‘alternative energy.’ ”
And it’s not just in the United States. A new report from the British energy think tank Ember shows that in 2023 the European Union—spurred in part by Russia’s invasion of Ukraine—in a month produced more electricity from renewable sources than from fossil fuels for the first time. In May, Ember reported that wind and solar are now growing faster than any energy sources in history, besting even the rate that nuclear power grew at its height, during the nineteen-sixties and seventies. Although new data released this week showed world carbon emissions still climbed slightly last year, the Rocky Mountain Institute, in a report released last week, declared that the world could see peak fossil-fuel use this year, as the surge in renewables could account for even the rising demand for energy from growing Asian economies. In the past decade, the R.M.I. group found, “solar generation has grown 12 times, battery storage by 180 times, and EV sales by 100 times.” This growth has been led by China, where “solar generation is up 37 times and EV sales up 700 times.” China is “poised to be the first major electrostate.”
Jacobson leads a team of researchers at Stanford who have modelled plans to take a hundred and forty-nine countries to a-hundred-per-cent wind, water, and solar power by 2035; the latest countries added to his database, this spring, are Madagascar, Rwanda, Uganda, and Eswatini (the former Swaziland). For each of them, Jacobson has a model that can forecast the weather every thirty seconds, for decades ahead, taking into account the predictions of a warming climate. If, on some June day in 2050, it’s going to be eighty degrees in the mountains of Madagascar, and you want it to be seventy degrees inside a home, he can calculate the insulation value of the wall of an average residential building there and show how much energy it will take to cool things down. Then he can show exactly what combination of wind, water, and solar will provide it. Very occasionally, he’ll find a place with so little land that it can’t produce the energy it needs on its own soil. (He limits the acreage to be used for solar and wind production to about two per cent of a nation’s territory.) “Singapore, Gibraltar, places like that,” he says. “Then we go offshore.” And, in the interest of grid stability, he tries to couple wind and solar in relatively equal amounts. “That’s because in a heat wave, you have high pressure, and lots and lots of sun, but the wind tends to die,” he says. “And then the low pressure comes in, and with it storms, which cuts the solar energy, but the pressure gradients mean strong winds.” Hydro is a reliable source—essentially the biggest battery on his grid, because its power can be so easily stored for dispatch when needed—but when a drought causes its availability to drop, that almost certainly means that there’s been a lot of sun. “Everywhere in the world, we can find ways to match demand for energy by supply and storage,” he says.
The crucial question, of course, is not whether this transition will keep growing—it will, because the cost of solar, wind, and batteries continues to fall dramatically. The question is whether it will grow fast enough to let us begin to catch up with the implacable physics of global warming. (Globally, May was the twelfth month in a row of record-high temperatures.) And here the news is a little less sanguine: at the current pace, according to a new study from the International Energy Agency, we will more than double renewable capacity by 2030, but to meet the targets set in the Paris climate agreement, we’ll have to triple it. As the I.E.A.’s director, Fatih Birol, said, “the tripling target is ambitious but achievable, though only if governments quickly turn promises into plans of action. Countries worldwide have a major opportunity to accelerate progress towards a more secure, affordable, and sustainable energy system.”
Governments are fickle, though—even blue-state ones. Earlier this month, Governor Kathy Hochul, of New York, killed off a congestion-pricing scheme designed to toll automobile traffic into Manhattan and raise money for the city’s mass-transit system. In California, Governor Gavin Newsom has come under fire for cutting back support to rooftop and community solar power in favor of vast utility-scale projects. Meanwhile, Donald Trump has promised, if elected in November, to “drill drill drill,” and to end offshore wind on “Day One.” Even the Biden Administration, by Jacobson’s calculation, is spending about forty per cent of the money from the Inflation Reduction Act on expensive schemes such as “carbon capture,” which is designed to allow the fossil-fuel industry to go on burning carbon, even though “it would be endlessly cheaper to just use the money to build more solar.”
Sometimes, critics look at California’s electricity prices, among the highest in the nation, and conclude that renewables must be the reason, Jacobson says. In fact, “it’s just the opposite.” California’s prices have been driven up by wildfires, which are often sparked by utility wires, and natural-gas disasters at San Bruno and Aliso Canyon. “If we didn’t have renewables, our prices would be much higher,” Jacobson told me. (He has data showing that the other American states with high renewable penetration—mostly Midwestern wind giants such as Iowa and the Dakotas—have among the lowest electricity costs in the country.) “The secret now is deploy, deploy, deploy. We have ninety-five per cent of the technology we need.”
The dimensions of California’s miracle can be measured from a house like Jacobson’s. (Most owners of solar-powered homes, in my experience, are evangelists, converted the first time they watch their meter spin backward.) But you can also measure it in other places, including an impossibly cluttered, small research lab in the industrial district of Oakland. Danny Kennedy is a veteran renewable-energy guru and the head of the New Energy Nexus, a nonprofit that helps companies leading the transition off fossil fuels. Kennedy had recently been insisting that I see a two-year-old startup in Oakland called Magrathea Metals, which, he said, is “making metal from seawater with sunshine.”
We found the lab, in a renovated warehouse, right next to a California-inevitable microbrewery and coffee roaster. When we stepped inside, someone in a welder’s helmet shouted, “Watch out, we’re pouring molten metal over here!” We scurried farther into the building, to meet two young men, Alex Grant, formerly a lithium technology developer, and Jacob Brown, a chemical engineer educated at Cambridge University. They are Magrathea’s founders, and they bubble with the energy of Silicon Valley-adjacent entrepreneurs. But, instead of producing apps, they produce magnesium, which is the world’s third most common structural metal, though it trails steel and aluminum by large measures, mostly because it’s traditionally more expensive to make.
But that’s potentially no longer the case, for reasons that show how renewable power can help transform industry itself—making it both cheaper and less material-intensive. To meet peak demand in places like California, you need to build a lot of solar panels, which means that when demand is lower you are producing more power than you can use, which, in turn, means that during those hours the power is very cheap. Magnesium can be smelted intermittently, partly because its melting point is low: you can start to heat up the feedstock in a smelter (there is a trial-sized one in a room isolated for safety at Magrathea) during the afternoon hours when solar productivity is at a peak, and then, when people come home and turn on their ovens and their washing machines, and the price of electricity goes up, you can turn off the smelter. Then you wait until electricity becomes cheap again, and resume smelting. It’s not feasible to do this with aluminum—the molten salt it is combined with will freeze.
Another reason magnesium could have less impact on the planet is that it doesn’t have to be mined, because it is found in the ocean—a hundred and forty-two gallons of seawater can yield a pound of metal. Or you can start with naturally occurring brines and salts, or the brine left behind by desalination plants. Grant calls himself a “brine nerd,” and he showed me trays of the stuff from Namibia and Western Australia, and from just up the Bay in Newark, California. Brine can be delivered by truck from Newark whenever the startup needs it. (Usually, brine is sold for keeping down dust on roads or de-icing them in the winter; milk of magnesia is another use.) “We think of it as farm-to-table metal,” Grant said. In a corner of the factory, he curates a small museum of things made of magnesium from around the world—snowshoes, a bicycle, a lawnmower, the gearbox from a helicopter. “We’ve had global automakers tell us, ‘If we had a supply chain, it’s a no-brainer. In a specific design, it’s lighter, easier to die-cast, and stronger than aluminum,’ ” Grant said. “All the fundamentals point to it being as competitive as aluminum, if the costs can come down—and intermittency is the key.”
“We’ll be making a thousand tons a year by 2035, a million tons a year by 2050,” Grant said. “We’ll probably develop our first big smelter in the wind belt, in the middle of the country, because the onshore wind is so cheap.” There will almost certainly be a market—the military, for one, uses a lot of light metals for things like airplanes and, currently, more than eighty per cent of the world’s magnesium supply comes from China, and the second-largest producer is Russia.
As we talked, we peered through a window in the room where the trial-scale smelter is set up. It looked like a rusted kiln with a giant electric cord running into it. But that old-school infrastructure is combined with a new-age vibe: a Solarpunk flag (a green-and-gold banner of the nascent Solarpunk movement) hung on a wall above the smelter, and just outside the room there was a neon number 42. Fans of the cult classic “The Hitchhiker’s Guide to the Galaxy,” by Douglas Adams, will remember that “42” is the answer to the question—arrived at by the computer Deep Thought after 7.5 million years of calculation—of the meaning of “life, the universe, and everything.” Grant and Brown also took the company’s name from Adams’s book—Magrathea is the planet that built other planets.
The hope is that companies like Magrathea can help build a more sustainable planet. Not only does the smelting process use just solar power and seawater, its main by-product is magnesium oxide, which, when released into the ocean, helps sequester carbon. Indeed, instead of turning to rust, as steel eventually does, magnesium breaks down into magnesium oxide. So, if a bike made of magnesium is left to disintegrate in a landfill, it will eventually break down into its component parts and flow to the sea, where it will help in the process of rebalancing the atmosphere. “It’s an inherently carbon-neutral primary metal,” Brown said.
“What’s happening in places like California is not just substitution—not just replacing dirty energy with clean stuff,” Kennedy told me. That’s important, of course—the most impressive of Jacobson’s statistics from this spring in California is that the amount of natural gas used for electricity generation has dropped more than forty per cent from last year, which is the kind of number that the climate crisis requires. “But remember when Wi-Fi replaced modems?” Kennedy asked. “It wasn’t just a better signal—people started thinking up a thousand new things to do with all that connection. That’s what abundant electricity means: we’ll be able to think differently.” ♦