Thermal batteries hit gigawatt-hour scale as lithium storage keeps sprinting

California-based Antora Energy said on 1 October that it will build a 5.8 gigawatt-hour thermal battery at an ethanol biorefinery in Pratt, Kansas, with equity financing led by Copenhagen Infrastructure Partners (CIP) and joined by Grok Ventures and University Pension Plan Ontario. It is one of the largest energy storage projects announced anywhere this year, and it isn’t a lithium-ion battery at all.

The same week brought a string of conventional lithium battery energy storage system (BESS) announcements: a 500 megawatt-hour project financed in Texas, an 828 megawatt-hour system under construction in Italy, a Maryland procurement that conditionally awarded 1,760 megawatt-hours of capacity credits, and a sodium-ion product launch in China. Taken together, the week’s news shows a storage sector that is scaling in two directions at once: lithium BESS keeps getting bigger and more routine, while a parallel track of long-duration, non-lithium technology is starting to attract the kind of institutional capital that used to go only to proven chemistries.

A thermal battery joins the gigawatt-hour club

Copenhagen Infrastructure Partners led the project’s third-party equity financing through its credit platform, with Grok Ventures and University Pension Plan Ontario also participating. The arrangement is structured as a long-term heat offtake agreement rather than a conventional power purchase deal. The commercial arrangement is a long-term heat offtake agreement, with energy deliveries scheduled to start in 2027, giving the biorefinery access to an around-the-clock supply.

Antora’s technology stores electricity as heat rather than in a chemical cell. Antora develops thermal batteries that store low-cost electricity as heat in insulated blocks of solid carbon and deliver the stored energy around the clock as industrial heat or power. The Kansas project follows an earlier commercial deployment: the manufacturer commissioned a 50 MW/5 GWh system in South Dakota in May, supplied by batteries built at its factory in San Jose, California.

The company has also raised substantial venture capital this year. The announcement follows a successful Series C fundraising round for Antora which saw the US manufacturer raise $550 million. On the ground in Kansas, the project is framed as an industrial jobs story as much as an energy one: the project with Pratt Energy is expected to create more than 100 construction and operation jobs, and Antora has said its thermal batteries will help meet Kansas’s rising energy demand while using little additional water beyond the biorefinery’s existing operations.

What the companies didn’t say

Trade press coverage has flagged a gap in Antora’s disclosure. The Kansas project follows Antora’s commissioning of a 5 GWh system in Big Stone City, South Dakota, which has a 50 MW rating; the Pratt announcement does not specify an equivalent power rating. One analysis was blunter about the omission: trade coverage rates that project at 50 MW and 5 GWh, so the omission in Kansas looks like a choice rather than an oversight, with capital cost missing too, along with the term of the heat offtake agreement.

The same pattern of selective disclosure shows up in this week’s biggest conventional BESS deal. Linea Energy, an independent power producer sponsored by EnCap Investments, closed debt and preferred equity financing for its 250 MW/500 MWh Mesa View project in Upton County, Texas, with NORD/LB arranging debt and D.E. Shaw Renewable Investments providing preferred equity. But as one analysis noted, Linea closed the financing without naming the amount raised, an offtaker, an EPC contractor or a cell supplier. Across both deals, the headline capacity numbers are solid; the economics behind them are not public.

Lithium-ion keeps scaling in parallel

None of this slows the much larger lithium-ion build-out. In Italy, BW ESS started construction on its second large battery project there in a month. BW ESS has started building its Cerignola, 97MW/828MWh battery energy storage system in the southern Apulia region for 2028 operations, a month after it announced construction on its 107MW/515MWh Chignolo Po project in northern Lombardy. A developer active in the same market described the shift in what the sector now needs most. Galileo’s Italy managing director Francesco Dolzani told Energy-Storage.News the business is now “less about attracting capital and more about execution” than it was when permitting was the bottleneck.

In the US state of Maryland, regulators conditionally selected two transmission-connected projects in the first round of a new bulk storage procurement. The finalists are Flatiron Energy’s 400 MW/1,600 MWh Chalk Point Storage Project in south-central Maryland and REV Renewables’s 40 MW/160 MWh Jade Meadow III Battery Storage Project in the far western part of the state. The round fell short of the state’s target: the Maryland Public Service Commission awarded Energy Storage Capacity Credits to two battery projects totaling 440 MW on October 1, 2026, against a sought 800 MW in this first round. The shortfall matters because of what is happening in the regional grid these projects feed into. The grid operator faces a capacity shortfall of 6.8 GW for the 2028-2029 delivery year, up 300 MW from the previous period, as capacity prices remain at the $325/MW-day cap.

Selected storage announcements, late September to early October 2026

Project	Location	Technology	Capacity	Status
Pratt biorefinery TES	Pratt, Kansas, US	Thermal (carbon block)	5.8 GWh	Announced; equity financed; deliveries from 2027
Mesa View BESS	Upton County, Texas, US	Lithium-ion	250 MW / 500 MWh	Financing closed; COD 2027
Cerignola BESS	Apulia, Italy	Lithium-ion	97 MW / 828 MWh	Construction started; target 2028
Chalk Point Storage	Prince George’s County, Maryland, US	Lithium-ion	400 MW / 1,600 MWh	Conditionally awarded capacity credit
Power N4.0MWh	China (product launch)	Sodium-ion	4 MWh per unit	Launched; full-scale production planned 2027
OX2 BESS (e-Storage)	Australia	Lithium-ion	100 MW / 200 MWh	Contracted for delivery

Announced battery storage project sizes, Oct 2026

Why duration is the real story

Most grid-scale lithium BESS today is built for short discharge windows. Maryland’s own procurement rules make this explicit: eligible projects must be designed to discharge at full power for at least four hours. Several projects announced this week fit that mould almost exactly, from Maryland’s own awards to the Texas and Australian deals. Thermal storage is aimed at a different problem: supplying continuous, around-the-clock heat or power over days rather than hours, which is what an ethanol plant with constant process heat demand actually needs.

Implied discharge duration of selected 2026 storage projects

A likely reading: the data shows lithium BESS and thermal storage are not competing for the same contracts. Lithium batteries are winning four-hour capacity and arbitrage business on wholesale grids; Antora’s thermal batteries are winning long-term heat supply contracts with individual industrial sites. The implied duration chart above, built from projects where both power and energy figures are public, shows why: Antora’s South Dakota system runs at roughly 100 hours of implied duration, two orders of magnitude beyond any lithium project announced this week.

A broader diversification wave

Thermal storage isn’t the only non-lithium technology picking up institutional attention this year. Chinese manufacturer Hithium used a September product launch to push sodium-ion toward utility scale, unveiling the ∞Power N4.0MWh, a 4 MWh sodium-ion energy storage system equipped with the new high-capacity ∞Cell N785Ah sodium-ion battery, representing a step up in capacity achieved in less than two years. The company is targeting aggressive costs: Hithium said it is targeting a quoted levelized cost of storage of RMB 0.1 per kWh, or roughly USD 1.5 cents per kWh.

Buyers remain cautious. Sources in one of Europe’s most developed BESS markets were quoted describing sodium-ion as “still very much on the fringe” of procurement decisions there, with lithium iron phosphate (LFP) remaining the default choice. Hithium’s own product manager acknowledged the technology still needs to clear safety hurdles before wide deployment, saying the company is conducting further safety testing on the new cell and system, with current work focused on thermal propagation, gas release and pressure relief, fire-protection coordination, thermal management and transportation safety.

Who gains, who carries the risk

Industrial energy users with steady, round-the-clock heat demand are the clearest winners from the thermal storage push: Pratt Energy gets an offtake-backed supply of low-cost energy without building its own generation. Infrastructure investors like CIP get exposure to a technology that, if it performs as advertised, offers long contracted cash flows similar to a power plant. Grid-scale lithium developers gain nothing directly from Antora’s deal, but they benefit from the broader signal that institutional capital still sees energy storage, in whatever form, as financeable.

The risk sits mostly with the thermal and sodium-ion technologies themselves, both of which are earlier in their deployment curve than lithium-ion BESS. Antora has only one earlier commercial-scale reference project, in South Dakota, and the Kansas deal arrives without a published capital cost or power rating. Sodium-ion suppliers like Hithium are asking developers to commit to a chemistry that European buyers still treat as unproven for bankable project finance.

The safety backlash shadow

None of this diversification happens in a vacuum. Grid-scale lithium BESS has faced growing local opposition in parts of the United States over fire risk, and that opposition has become a live political issue. A Washington Post opinion piece this week argued the backlash is often misdirected, writing that battery storage facilities “ease the strain on the grid from data centers, but they’re treated as part of the problem,” a framing attributed to authors Brian Deese and Anna Pasnau rather than to any regulator or safety body. Market researchers, meanwhile, are tracking rising demand for hardware built specifically to detect battery thermal runaway, tied to tightening BESS safety mandates in multiple jurisdictions, according to a forecast published by IndexBox. Whether that demand curve is driven more by genuine risk reduction or by reputational pressure on developers is an open question the data alone can’t answer.

Risks and open questions

Capital cost opacity. Neither Antora nor Linea Energy disclosed project costs this week, making it hard for outside analysts to judge whether thermal storage economics actually beat lithium-ion on a levelized basis for industrial heat applications.
Technology risk at scale. Antora’s Kansas system would be larger than its only operating commercial reference plant, and the company has not published a power rating for it.
Bankability gap for alternative chemistries. Sodium-ion and other emerging technologies still lack the track record that lenders typically require for non-recourse project debt, unlike the now-routine financing structures available to lithium BESS.
Policy and siting friction. Capacity shortfalls in grids like PJM are pushing procurement forward, but local opposition to lithium BESS siting in some US communities could slow the pace of the much larger conventional buildout that still dominates total storage capacity.

What to watch

Watch whether Antora publishes a power rating or capital cost for the Kansas project as it moves toward construction, since that disclosure would let analysts compare its economics against lithium alternatives directly. Watch Maryland’s second procurement round, due by 1 January 2027, for whether the state closes the gap left by Round 1’s shortfall against its 800 MW target. And watch whether any European or North American developer actually commits sodium-ion cells to a contracted grid-scale project this year, which would be the clearest sign yet that the technology has crossed from pilot status toward bankability.