GrafTech International and Antora Energy have announced a collaboration to develop and supply carbon-based materials for the latter’s thermal batteries.

Under the plans outlined, production will take place at GrafTech’s St. Marys facility in Pennsylvania, US.

The companies stated that the partnership aims to reinforce domestic manufacturing capabilities in energy technology.

Both companies have resumed and expanded operations in St. Marys, with GrafTech restarting eight bake furnaces to meet demand for the project.

The collaboration has already led to new hiring at the facility. At least a dozen additional positions are anticipated across several areas including operations, machining and maintenance.

GrafTech International CEO and president Timothy Flanagan said: “This partnership is expected to utilise a significant portion of the bake furnace capacity at St. Marys, creating an important new application for the facility while diversifying our end markets and supporting the growth of the domestic energy storage supply chain.

“We are particularly pleased that this opportunity builds on the skills and experience of the St. Marys workforce, and we look forward to growing our commercial relationship with Antora.”

Antora’s batteries store electricity as heat using insulated blocks of solid carbon, before delivering this energy as heat or electricity as needed.

The modules, manufactured at the factory, can be deployed in sectors such as chemicals, food production, steel, data centres, or the grid.

Production of these batteries uses lower-purity carbon feedstocks including petroleum coke and coal tar pitch, processed in high-temperature furnaces.

According to the companies, growing demand for thermal energy storage could open new uses for byproducts from the US petroleum and coal industries.

Antora co-founder and CEO Andrew Ponec said: “By partnering with GrafTech to source carbon-based materials from their St. Marys facility, Antora is strengthening our domestic supply chain.

“GrafTech is a leading Pennsylvania manufacturer, and we are excited to work with them to deliver affordable and reliable energy across the country. This is an investment in America’s energy leadership.”

The collaboration between GrafTech and Antora is currently governed by a memorandum of understanding.

Final agreements will depend on negotiation of definitive terms and conditions.

In July 2026, Antora Energy completed a $550m Series C funding round to support the rollout of large-scale thermal battery storage systems in the US.