Antora plans 5.8 GWh thermal battery at Pratt Energy's Kansas biorefinery

Antora Energy will put a 5.8 GWh, multi-day thermal battery at Pratt Energy's ethanol biorefinery in Pratt, Kansas, and start delivering energy to the plant in 2027 under a long-term heat offtake agreement, the company said on October 1, 2026. Copenhagen Infrastructure Partners (CIP) led the project's third-party equity financing, with Grok Ventures and University Pension Plan Ontario also participating. Antora says the project, once complete, will be one of the largest battery storage systems in the world.

Antora's carbon blocks will deliver heat around the clock to a plant that has been turning regionally grown corn and sorghum into ethanol since 2013. The modules store low-cost electricity as heat in insulated blocks of solid carbon and deliver it as heat or power, per the release; at an ethanol plant the product is heat, and the Pratt contract is a heat offtake, like Antora's contract at POET's Big Stone City plant in South Dakota. Antora says the energy will make Pratt's operations more efficient and its products more competitive, and will help Pratt Energy move toward what the release calls 100% zero-carbon-intensity ethanol, which it says would open new markets for Kansas agricultural products.

Pratt Energy also sells co-products used for biodiesel and animal feed, per the release's company description. EIA's fuel ethanol plant capacity data as of January 1, 2025 lists Pratt Energy LLC at 55 million gallons a year, one of 12 Kansas plants in the table and under half the 121 million gallons EIA lists for the state's largest, Arkalon Ethanol in Liberal.

Antora expects the project to create and support over 100 construction and operations jobs and says it will prioritize local candidates for the plant's permanent operations roles. It has a paid internship program with Pratt Community College; two students from the college's Electrical Powerline Technology program spent the summer of 2026 at the Big Stone project. Through the South Central Community Foundation, Antora is funding scholarships for up to 12 Pratt students over three years and a Pratt Community Impact Fund that will make grants from 2027. "Antora came to Pratt early, listened, and followed through on their commitments: local hiring, internships, and scholarships for our students," said Kyle Farmer, the mayor of Pratt, in the release.

The release accounts for the project's water (little beyond the biorefinery's existing use, Antora expects) and its noise (no increase for neighboring properties, also expected), but on the charging side it says only that the energy is locally produced: it names no utility, no rate, no charging capacity in megawatts (the kW vs kWh distinction matters here: 5.8 GWh says how much the blocks hold, not how fast they fill), no construction date, no price, no financing amount and no contract term, and it cites no Kansas Corporation Commission filing.

The Big Stone template

Pratt is, by the release's own count, the second major project Antora has announced in 2026, and the first one answers the question the second leaves open. Antora and POET announced on May 19, 2026 the commissioning of a 5 GWh system of over 200 thermal batteries at POET's Big Stone City, South Dakota bioprocessing plant; it went from initial construction to delivering energy in under 12 months, and Antora expected full operation later in 2026. There, per the May release, Antora worked with Otter Tail Power on an electric rate that the South Dakota Public Utilities Commission approved in 2025, which lets the system charge selectively and rapidly during periods of surplus local energy production and which Antora says keeps costs from rising for other consumers.

Nothing in the Kansas release describes an equivalent arrangement. Its cost claim is made at the level of customer bills and tied to no named rate, utility or commission approval. "American industry runs on affordable, reliable energy," said David Bierman, Antora's co-founder and chief commercial officer, in the release. "Our partnership with Pratt Energy delivers it, helping meet Kansas's rising energy demand without increasing power bills for homes or businesses."

The money has changed shape between the two projects. Grok Ventures was the sole external investor in the Big Stone project financing, per the May release; at Pratt it is one of two investors the release names alongside CIP's lead, which the October release describes as part of CIP's credit platform investments. Antora itself closed a $550 million Series C on July 30, 2026, co-led by G2 Venture Partners and Eclipse, to deploy large projects, expand production, set up a second US manufacturing hub and strengthen its domestic supply chain. The heat-or-power option rests on thermophotovoltaic cells developed with ARPA-E support: the agency selected Antora in June 2024 for award negotiations on up to $14.5 million under its SCALEUP program for a combined heat and power product.

Outlook

A 2027 delivery start, read against Big Stone's run from initial construction to energy deliveries in under 12 months, puts construction at Pratt somewhere between late 2026 and late 2027, depending on when in 2027 deliveries begin; the release gives no month, and Antora has given no construction date. The open item in the release is the electricity: the Big Stone arrangement, as Antora describes it, needed a utility and a state commission's approval of a rate, and the Kansas release names neither for Pratt. Antora's Series C release describes a growing pipeline of signed agreements with hyperscalers and industrial leaders, which suggests more site announcements to come; it gives no timing.