Which Companies Manufacture Utility-Scale Batteries in the U.S.?

Utility-scale batteries are the quiet giants of the clean-energy boom. They charge when electricity is cheap, then feed the grid during peaks, storms, or sunny evenings after the sun slips away. Ten years ago the hardware was almost all imported. Today a growing club of companies makes, assembles, or plans to build huge battery packs on American soil. Below is a plain-English tour of the biggest players, what they build, and why each name matters.

1. Tesla (California and Nevada)

Tesla began shipping “Megapack” systems from its Fremont line in 2019. Demand grew so quickly that the company opened the Lathrop Megafactory near Stockton, California. The plant can churn out roughly 40 gigawatt-hours (GWh) of storage each year, equal to about 10,000 Megapacks. Production uses lithium-iron-phosphate (LFP) cells supplied by partner factories; Tesla integrates them into ready-to-ship containers that arrive on a truck, plug in, and start working. The firm also draws cells from its longtime Gigafactory in Nevada.

Why it matters: Lathrop is the largest dedicated grid-battery factory in North America. Scale drives down cost, and Megapack is often the cheapest turnkey option for four-hour storage projects.

2. LG Energy Solution (Michigan)

In June 2025 LG Energy Solution flipped the switch on a new Holland, Michigan plant focused on LFP cells for energy-storage systems. Two production lines are running, a third is due by year-end, and full capacity will reach 16.5 GWh. LG says every cell from this site will feed stationary projects such as utility batteries and microgrids, not electric cars.

Why it matters: Domestic cell supply helps developers claim the Inflation Reduction Act’s extra tax credit for U.S.-made content, closing price gaps with imported packs.

3. Form Energy (West Virginia)

Most grid batteries run for four hours. Form Energy is chasing multi-day storage with an iron-air chemistry that breathes oxygen in and out of cheap iron pellets. The first commercial factory, called Form Factory 1, broke ground in Weirton, West Virginia, and began pilot production in late 2024. When fully ramped the site will produce 500 megawatts (MW) of batteries each year.

Why it matters: If the iron-air design hits its performance goals, it could lower long-duration storage costs by 70 percent or more—something lithium cells struggle to match.

4. ESS Inc. (Oregon)

ESS builds all-iron flow batteries in Wilsonville, Oregon. Instead of storing energy in solid cells, flow batteries pump electrolyte through stacks, storing energy in tanks that scale easily for eight- to twelve-hour duration. The company’s Energy Center platform ships in containerized units ready for utility substations.

Why it matters: Flow batteries avoid lithium and use common iron salts, cutting fire risk and supply-chain pressures. They last for tens of thousands of cycles with almost no capacity fade.

5. Powin (Oregon and Southeast)

Powin assembles complete battery-energy-storage systems (BESS) in Oregon and is expanding into Tennessee, Georgia, and South Carolina through supply-chain partners. While cells still come from overseas, Powin builds packs, racks, enclosures, and its own software in the U.S., securing about 5 GWh of annual domestic production starting in 2025.

Why it matters: Many utilities award points for U.S. content even when cells are imported. Powin’s modular “Stack” products let developers claim some of those points and shorten delivery times.

6. Fluence (Utah)

Fluence, a joint venture of Siemens and AES, is best known for integrating batteries into turnkey projects worldwide. In 2024 it began producing battery modules and enclosures in Utah, supporting major projects like the Eleven Mile Solar Center in Arizona. Although cell supply is global, domestic assembly qualifies Fluence systems for content bonuses and faster logistics.

Why it matters: Fluence software runs a large share of grid batteries already online. Local module lines tighten quality control and help U.S. customers clear federal-funding hurdles.

7. General Motors + Redwood Materials (Nevada and Beyond)

Automaker GM is teaming up with Redwood Materials, the Nevada recycling startup founded by Tesla co-founder JB Straubel. The partners will build storage units that blend new LFP cells with recycled electric-vehicle packs. Redwood is also constructing a cathode-anode campus in South Carolina. First commercial systems will back up an AI data site in California later this year.

Why it matters: Repurposing used EV packs cuts material costs and squeezes more life from mined metals. The partnership also shows automakers see grid storage as a second profit pillar alongside cars.

8. American Battery Factory (Utah)

American Battery Factory, spun off from Lion Energy, is planning a network of LFP cell gigafactories starting with a flagship plant in Cedar City, Utah. The company targets off-grid, residential, and grid-scale storage markets. Full output from the first phase will exceed 3 GWh.

Why it matters: Homegrown LFP cells reduce reliance on overseas suppliers and align with federal incentives for domestic content, giving smaller developers more sourcing options.

Honorable mentions

Panasonic Energy (Nevada and Kansas) produces cylindrical cells mainly for cars, yet some utility integrators buy those cells for storage racks.
Natron Energy (Kansas) will begin making sodium-ion cells in 2026, which could feed future grid projects.
ESS-style startups such as Ambri and VoltStorage are testing novel chemistries and scouting U.S. factory sites.

Trends to watch

Shift to LFP: Almost every new U.S. line uses lithium-iron-phosphate because it skips nickel and cobalt, cutting cost and supply risk.
Long-duration leap: Iron-air, flow, and sodium-ion factories aim to serve eight-hour-plus markets where lithium struggles.
Recycling loops: Redwood Materials and Li-Cycle show that recycled metals can supply cathodes locally, easing import pressure.
Domestic-content credit: The Inflation Reduction Act rewards projects using U.S.-made cells or packs, pushing more firms to add stateside lines.
Automaker pivot: GM and potentially Ford view grid storage as a hedge against slower electric-car growth, tapping existing cell know-how for new markets.

What it means for developers

For companies like Sunland America, a deeper U.S. supply chain means:

Faster delivery: Shorter shipping routes and cleared customs mean projects hit milestones sooner.
IRA bonus points: Using U.S. cells or packs can add up to 10 percentage points to federal tax credits, improving returns.
Diverse chemistry menu: Developers can pick lithium for four-hour peaks, iron-air or flow for multi-day needs, and mix chemistries across a portfolio.

The roster of domestic manufacturers may double again before 2030, but even today there is no shortage of American-made hardware ready to keep the lights on.