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Hertz backtracking on EV rentals is not a surprise.

A year ago, before a vacation to see the eruption of the Hawaiian volcano Kīlauea, I found myself scrolling through my rental car options. A few users on the car-sharing service Turo offered up their Tesla Model 3s, and I was tempted by the idea of driving electric on holiday just as I would at home. One problem: There are no superchargers on the Big Island. I opted instead for a dependable, decade-old Hyundai Sonata — one that cost half as much per day.
An electric rental car is an easier sell in a big city with plenty of fast chargers. Even so, it appears that Americans at large are making the same choice that I did. Rental car giant Hertz made a big splash by adding Teslas to its fleet in 2021 and using NFL legend Tom Brady to advertise them. Now, instead of scaling up to 25% EV by this year as it had once planned, Hertz says it will sell off a third of its EVs because of weak demand and higher costs. The company plans to use the money to shift back toward more gasoline-powered cars.
I can’t say I’m surprised. EVs are, at least for this moment, an awkward fit for America’s rental car economy.
On the one hand, a rental is a great way for someone with no time behind the wheel of an EV to experience the reality of ownership. As a member of the car press, I got to test a Model 3 for several days before I bought my own. Believe me: A brief test drive from the dealership is nothing compared to what you’ll learn from puttering around in one of Hertz’s EVs for a few days, getting accustomed to its user interface and to the task of recharging. If you’re thinking about buying an electric car and you have a vacation in the near future, I’d encourage you to take the opportunity. An EV rental car is also an attractive option for lowering a vacation’s environmental footprint, since you’re probably already flying in a carbon-spewing airplane.
A rental car is also a good excuse to drive something fun or goofy. On a business trip a decade ago, I fulfilled a boyhood daydream by taking the bright red Jeep Wrangler and bombing around the San Francisco Bay Area with the top down (thanks, corporate card). A weekend car rental offers the chance to hop in a Tesla, which remains an usual or exotic experience in most places outside of California. However, Hertz’s struggles suggest that allure isn’t enough to overcome the higher cost of renting an EV. Especially when the bottom-dollar beater gets you where you’re going, if not in style.
The biggest issue, of course, is the fear of the unknown. Because so few Americans own a pure EV, renting one means learning a new driving paradigm — a chore, if not an outright headache. The last thing most people want to do while traveling to a conference in Boston or vacationing to the beaches of Los Angeles is to figure out how to put a Tesla into reverse or worry whether there’s a supercharger close to the hotel.
In truth, it’s not so bad. Once you’re inside an electric vehicle, the experience is built to be as idiot-proof as possible. Most modern EVs feature a big touchscreen with a map that will route you to available charging locations. The car will make sure to warn you, repeatedly, if it thinks you’re letting the battery get too low or straying too far from available chargers.
As much as the vehicle’s UI strives to inspire confidence, though, it’s easy to see why drivers who don’t already own EVs feel wary. The Biden administration’s big push may indeed expand America’s charging infrastructure. For now, though, there are still plenty of horror stories of people beset by busted plugs, slow chargers, long lines, or lousy interfaces. Vacation is supposed to be about decompressing, not range anxiety. Until chargers become much more reliable and get closer to ubiquitous, travelers will choose the known quantity: pump gas and put away the climate part of their brain.
That’s not to say EVs are doomed in the rental car market, or that tourists will forever spew carbon emissions from the backs of their battered Nissan Altimas and Honda CR-Vs. As Bloomberg reports, Hertz is paying close attention to GM’s attempts to revive the Chevrolet Bolt and introduce an electrified Equinox crossover as entry-level EVs in the low $30,000s. At that level, an agency could rent out EVs at prices more competitive with their traditional gas-burners. As EVs grow cheaper to rent and drivers grow more confident about charging, some of them will think hard about renting electric — especially in times of spiking gas prices. Perhaps a day will come when companies require their traveling employees to rent EVs instead of combustion cars as a way to keep costs down or to contribute to the firm’s green claims.
In the meantime, the question of rental EVs hovers in the same moment of uncertainty that clouds everything EV. Sales of electrics are not slowing, despite reports to the contrary. However the legacy automakers are seriously struggling with their electric transitions. Heatmap’s reporting has shown a major partisanship-based gap in EV buying interest, and that drivers in much of the country aren’t nearly as interested in buying electric cars as Ford and GM have suddenly become in selling them. The bad vibes are enough to make one wonder whether those living outside of large, EV-friendly large cities will ever embrace owning an EV, let alone become comfortable enough to rent one the next time they fly the family to Disney World.
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Have data centers already peaked as an economic and energy trend?
This is Heatmap Daily, a weekday digest written by our executive editor. Subscribe here.
Covering energy and climate change sometimes means seeing certain stories in a different light than others. And a particularly vivid hue illuminated The Wall Street Journal’s report today that the Japanese conglomerate SoftBank Group is taking a $3.7 billion loss on several gigawatts’ worth of natural gas turbines.
For the Journal, the big news is that SoftBank and its billionaire founder, Masayoshi Son, are failing to capitalize on the artificial intelligence boom. But at Heatmap, we’re thinking about the turbines.
The data center boom and the return of electricity load growth has depleted the world’s supply of natural gas turbines. SoftBank had purchased reservations for about 13 gigawatts of turbines, according to the Journal. That’s a staggering amount of electricity — it could meet New York City’s maximum power draw on the hottest part of a summer’s day. The conglomerate now seems set to dump reservations for about four gigawatts’ worth. Keeping a reservation, it turns out, really is harder than making it.
Most of those rotors were reportedly from GE Vernova, one of the world’s largest producers of gas turbines. GE Vernova’s order list for gas turbines has been filled for nearly two years and the waiting list now stretches into 2031. That has led data center developers, hungry to get power as soon as possible, to reach for ever dirtier forms of electricity generation, including diesel generators and even old jet engines.
On that front, SoftBank’s failure to sell the turbines to a higher bidder suggests (albeit weakly) that demand for energy-producing assets might not be as strong as the AI boom’s backers once thought. SoftBank was already set to send about 9 gigawatts of turbines to the enormous Trump-backed OpenAI data center in Pike County, Ohio. The roughly remaining four gigawatts will be released back their manufacturers. (One thing this news can’t quite tell us, alas, is what type of turbine set-up will be used in the Pike County facility, which will be the world’s largest gas-fired power plant if it is build to completion. Recent public filings have suggested the facility isn’t planning on using any turbines in the more efficient combined-cycle configuration, which would mean the plant’s carbon intensity will be worse than most other new natural gas plants. But we’d love to hear any tips on this front.)
To zoom out for a second, I’m struck by how the AI bubble has been replaced by an AI muddle. As I wrote this, news emerged that Nvidia is preparing to fire its CEO, Jensen Huang, for his affair with a Chinese woman who is alleged to be a spy. Under Huang’s leadership, Nvidia has invested in a sprawling and sometimes circular network of energy-related companies, including Emerald AI, which helps data centers flex their electricity demand, and Redwood Materials, a battery recycler and producer led by the former Tesla executive JB Straubel. Huang has used Nvidia’s enormous balance sheet to buy down the risk of other AI and AI-related companies. Now that balance sheet is in peril: Its stock is already down 11% over the past five days, and it has fallen another 8% in after-hours trading since the news of Huang’s ouster broke. If its financial network began to fray — or even if the next CEO had a different risk appetite than Huang — then its demise could impact a much larger set of firms.
Even before the Huang scandal broke, firms at the center of the AI trade were struggling. Alphabet, Meta, and Microsoft are all down on the month. Nvidia was already lagging by about 10% before the late unpleasantness, too. The memory and chip makers Micron and Applied Materials are both down more than 25%, and GE Vernova and Oklo have fallen nearly 20%. Although the data center company Coreweave beat earnings today, it’s still down 24% on the month and nearly 50% since May.
The market rout isn’t total — Anthropic seems likely to enjoy one of the largest IPOs ever in the next week (although perhaps not with quite as large a valuation as its investors once imagined). And the underlying technology of AI seems to keep getting worryingly better all the time. But even though the politics of data centers seem set to dominate the new Washington, I’m wondering if data centers as an economic trend might have already peaked.
Lunar Energy’s latest AI-powered system aims to integrate EVs into the automated demand response mix.
In theory, it’s straightforward to assemble the smart energy home: Solar panels, home backup batteries, and electric vehicles, plus smart thermostats, heat pumps, and water heaters — all the individual pieces can be had for the homeowner who can afford the up-front cost. The challenge is getting all those pieces to talk to one another.
Bay Area-based Lunar Energy is one of the tech firms that’s been trying to crack this problem. Today, it announced an upgraded version of its artificial intelligence-powered home energy control system, which not only integrates all those separate systems but also responds tactically to energy markets. CEO Kunal Girotra told me Lunar AI saves its users money by monitoring their home 24/7 and making decisions to charge, not to charge, or discharge so that they save the most money.
“Utilities are all moving to almost-real-time changes of rates,” he said. “You need software to handle that for you. I think that the race is on for who has the best AI machine learning algorithms to save the most amount of money. And so far, we seem to have a head start.”
Lunar’s first-generation system focused on generation, storage, and control. In other words, it connected elements like a home’s rooftop solar panels with the backup battery the residents might keep in the garage, using the AI to decide when to meet the home’s real-time energy needs with solar versus grid energy versus stored power. What it didn’t have was the ability to work with electric vehicles to manage charging and use the car’s battery as a bonus source of energy.
To fix this, Lunar has built its own bidirectional EV charger — one that can charge up the battery or discharge the car’s battery for a secondary use, like backing up the home’s power supply. Girotra, formerly the head of Tesla Energy, told me the problem with that functionality to this point has been the connection point between the car and the home electrical system. Carmakers and other companies in the space didn’t have the deep experience with electrical certifications to make the process seamless, he tells me. That led to setups like the original Ford Charge Station Pro, which required several different wall-mounted electrical boxes to connect the F-150 Lightning EV to the home.
Lunar’s charger is built to connect to its customers’ existing home Lunar energy system, which includes a microgrid interconnect device they call Lunar Bridge that islands the home in case of a power outage on the grid. In that way, the power stored in the EV battery is ready to back up the home in case of a blackout without any additional work — or to be optimized as part of a fully smart home that’s making money as part of a virtual power plant.
The company’s setup allows for another fun feature: “slow” charging that’s not slow at all, but actually two or three times as fast as the Level 2 charging most EV owners use to recharge their batteries overnight. Electric cars in the U.S. can typically take on only about 11 kilowatts of AC power from one’s home because of the limitations of their on-board hardware. Because Lunar’s system is fully DC, however, Girotra said the company decided to build a DC home charger, one that — like a Tesla Supercharger or other DC fast chargers out in the world — isn’t limited by that power cap. Lunar said it could use a combination of power from the grid, home solar, or home batteries to charge an EV at up to 25 kilowatts. That’s enough to recharge an EV in three to four hours rather than six to eight.
“If the standards get high, and if everybody sees cars can get charged in three hours, then all of a sudden people are like, ‘Wow, this is how I want it,’” he said. “Especially for 25% of the users who are like me, who always are running low on charge and they don’t mind a boost every now and then.”
Some of the other improvements in the second-gen system are more incremental. An inverter that’s 40% more powerful helps Lunar get its system up to enterprise scale. That’s crucial, as the world moves toward a place where more homes and businesses employ battery backup systems. Lunar’s new batteries come in modular 5 kilowatt-hour blocks ranging from 10 kilowatt-hours to 30 kilowatt-hours in a single unit and scale up to 300 kilowatt-hours for home or small commercial use; there’s also new pad-mounted configurations with capacity up to 1 megawatt-hour.
Batteries, though, are the simple part. Everyone from EV makers like Rivian to utilities like Octopus Energy is racing to make a person’s or a business’s batteries and solar panels and electric cars work for them, using the power of AI to account for moment-to-moment changes in energy prices and supply. Lunar’s new tech makes the case that the most important element is a single brain to integrate every last smart, electrified thing in your house.
The fundraise comes on the heels of a $50 million grant from the Department of Energy.
Almost all lithium-ion batteries on the market rely on graphite for their anodes, more than 90% of which is processed in China. That concentration has created a chokepoint in the Pentagon’s supply chain as the military increasingly turns to batteries to help its transportation network operate more quietly and reduce reliance on complex refueling logistics.
So when Congress passed the latest National Defense Authorization Act at the end of 2025, barring Chinese-linked battery materials from military use starting in 2028, Coreshell saw an opening. While the California-based silicon-anode battery startup had previously focused on automakers as its beachhead customers, it’s now shipping its first battery cells to the military for use on Navy ships and Army ground vehicles. On Wednesday, Coreshell announced a $30 million Series B to scale up manufacturing operations to meet the needs of this growing customer base.
“We’re entering a new stage where we’re no longer, I would say, demand limited,” Coreshell’s CEO Jonathan Tan told me. “This year we’ve had to put on second and third shifts, work nights and weekends, just to get the product out the door.”
Coreshell sets itself apart by going a step further than the NDAA requires. The law doesn’t make suppliers trace battery materials all the way back to the mine, which would be exceedingly difficult given China’s dominance across the battery supply chain. But Coreshell has nevertheless eliminated Chinese sourcing from its anodes by replacing graphite with silicon mined and refined in the U.S. by Ferroglobe, one of its Series A investors.
Ferroglobe and global investment firm Access Industries led the latest round, with defense contractor ADS also joining as a new strategic investor. The financing comes on the heels of a $50 million Department of Energy grant that Coreshell secured in August as part of a program to strengthen the domestic battery supply chain. That funding will support the company’s first commercial-scale facility, a 2-gigawatt-hour factory.
That’s about 20 times the size of the 100-ish-megawatt-hour plant the startup had originally envisioned, as the DOE grant has allowed Coreshell to “expand much further than we were originally expecting,” according to Tan. The company is now evaluating several potential U.S. sites and expects to announce its selection early next year. For now, it relies on unnamed contract manufactures, along with its small pilot line in San Leandro, to produce its cells. But once the gigafactory gets up and running, the startup plans to bring electrode production in house by 2028, followed by full cell assembly in 2029.
Building this plant will ultimately require significant additional capital. But Tan believes this latest vote of confidence from the federal government will help Coreshell to diversify its capital stack as it continues to fundraise. “That’s one of the great things about having such a notable DOE award is that it also allows us to attract multiple forms of capital,” he told me.
Silicon has long been recognized as a promising alternative material for battery anodes, as it can store far more energy than graphite. The catch is that it tends to swell during charging, causing it to break down quickly and ultimately leading to a much shorter cycle life. Coreshell says it’s extended its anode’s lifespan by giving it a proprietary coating, which Tan told me back in April essentially means “painting the inside of your battery” with an ultra-thin protective layer.
Other companies, such as Sila Nanotechnologies and Group14 Technologies, are also working to commercialize silicon anodes. But Coreshell says many of its competitors rely on more highly engineered, expensive forms of silicon, such as silane gas. By contrast, Coreshell uses metallurgical silicon, a cheap, raw commodity already widely used in aluminum alloys. That, Tan argues, gives the company a cost advantage not only over its competitors, but potentially Chinese graphite too.
Coreshell hasn’t yet demonstrated that its cells can meet the performance demands of the automotive industry, however. When the company raised its Series A in early 2025, it said it expected its automotive cells to exceed 1,000 charge cycles while retaining 80% of their original capacity. But Tan told me many defense applications don’t require such demanding performance targets, as Navy ships and ground vehicles are “not intending to have as many miles or missions or use cases on that same battery” as a consumer EV would.
That doesn’t mean the company is abandoning its automotive ambitions. As Tan pointed out, electric vehicles remain by far the largest source of global and domestic battery demand. “It’s natural for us to obviously utilize the security supply chain first,” he told me. “That allowed us to really get to commercialization, revenue, and production faster, because automotive qualification is this longer journey. But ultimately, we want to do both of those and more.”