By Christopher Otts

Big U.S. EV battery makers are stepping back from the market that got them started and betting on a new set of customers in an entirely different business.

Instead of carmakers, these companies have started making batteries for utilities, wind- and solar-power developers, and massive data centers that train artificial intelligence.

Selling large, stationary batteries for "energy storage systems," or ESS, used to be a niche market that wasn't worth much attention, said Jaehong Park, an executive at the battery arm of South Korean conglomerate LG.

"ESS was the ugly duckling for a long time within our organization," Park said.

Five years ago, automakers and battery companies raced to build multibillion-dollar electric-vehicle battery plants across the U.S. South and Midwest, based on EV forecasts that proved too optimistic. Now, many of these plants are underused, delayed or stuck in limbo. Energy storage has emerged as an alternative, helping to compensate for the slowdown in electric vehicles.

Tesla generates billions of sales from batteries for energy storage. Revenue from the storage segment, which also includes solar panels, grew 67% last year to $4 billion, partially offsetting a $6 billion fall in revenue from EV sales.

Some of Tesla's biggest customers for its Megapack battery systems are utility-scale energy providers such as Intersect, as well as Tesla chief Elon Musk's separate artificial-intelligence company, xAI. xAI purchased $191 million of Tesla Megapack products in 2024, according to financial disclosures. Tesla didn't respond to a request for comment.

On Wednesday, General Motors said it is exploring an arrangement to supply energy-storage batteries to Redwood Materials, a startup company focused on battery recycling. Under the proposed deal, GM would supply Redwood with a mix of new and used GM batteries for large battery-storage systems.

"Right now, there is a hunger for more energy from every source," Redwood founder J.B. Straubel said.

Other battery makers are also pivoting. A Chinese-owned battery manufacturer that had planned to supply Mercedes-Benz is now considering energy storag e to help get a stalled factory in Kentucky back on track.

This shift is in response to a turn in U.S. electricity demand, which is growing again after about 15 years of stagnating. Several factors driving that growth are artificial-intelligence data centers, manufacturing and broader electrification.

Energy storage systems can help offset power outages and manage this extra demand on the power grid. Installations of energy-storage batteries more than tripled in the U.S. from 2021 to 2024 and are projected to grow 34% in 2025, according to energy consulting firm Wood Mackenzie.

"If you have an outage of a massive data center or a giant gas plant, batteries can plug that hole," said Stephanie Smith, chief operating officer of Eolian, a battery and renewable-energy company owned by asset manager BlackRock. "They can react in microseconds, and so you're able to address so many different problems on the entire grid."

China has dominated the energy-storage battery market. Chinese manufacturers have spent decades honing the low-cost chemistry that works best for stationary batteries, said Sam Adham, a battery expert at CRU, a market-research firm. Even with the Trump administration's ratcheting of tariffs on Chinese imports, China is still often the lowest-cost option for storage batteries, he said.

Now battery companies in the U.S. are trying to take on their Chinese competitors.

LG's battery unit, which co-owns EV battery factories with GM, Honda and Hyundai, became serious about diversifying its U.S. business in late 2023. The EV market was showing signs of softening, while the energy-storage business was heating up.

At that time, the company was building out multiple battery plants around the U.S., and last year it decided to shift things around, in what one executive likened to playing Tetris with its footprint.

A $1.4 billion expansion of its Holland, Mich., plant -- originally planned for EV battery production -- instead became LG's first U.S. facility dedicated to stationary storage batteries. It is using the same low-cost chemistry that Chinese companies have honed to dominate the business.

"We saw there is a rapid and urgently growing demand in the U.S. Here's an opportunity for us to address it more quickly," said Tristan Doherty, the company's chief product officer for storage batteries. The pivot put LG into the U.S. energy-storage business a year earlier than planned, he said.

Even with the moves, the company's results were hit by the pullback in EVs, with sales shrinking 24% last year. It expects EV demand in the U.S. to fall 10% this year, and aims to slash its capital spending by as much as 30%.

"Rather than building new capacity on new sites, we do want to try to maximize and fully utilize the existing sites that we have as much as possible," Chief Financial Officer Chang Sil Lee said in January.

Excelsior Energy Capital has signed an agreement to buy batteries from LG's new Michigan plant for its portfolio companies such as Lydian Energy, a utility-scale solar and battery developer.

U.S.-made batteries ensure projects aren't thrown off course, said Anne Marie Denman, co-founder of Excelsior.

"We can look our buyers of power straight in the eye and say, 'This is a domestically sourced supply chain and we can commit to these timelines,' " she said. "It isn't subject to geopolitical winds."

Write to Christopher Otts at christopher.otts@wsj.com

(END) Dow Jones Newswires

July 21, 2025 07:00 ET (11:00 GMT)

Copyright (c) 2025 Dow Jones & Company, Inc.