Saving electricity in a block of heat

Antora is using hot carbon blocks to supply industrial energy. A South Dakota project shows why a heat battery must be read differently from an electricity battery.

Select an underlined term for a short explanation.

At POET's bioprocessing plant in Big Stone City, South Dakota, a new energy system is intended to help keep industrial production supplied with heat. In May 2026, Antora and POET announced commissioning of a 5-gigawatt-hour thermal-storage project. Their release said energy delivery had begun, while full operation was expected later that year. The distinction matters: commissioning describes a transition into operation, not automatically completion of every stage.

Antora's approach starts with resistance heating. Electricity heats solid carbon blocks, which retain energy for later delivery. The company's technology page describes releasing that stored heat to industrial processes, or using steam equipment to generate electricity. It places direct conversion through specialised light-sensitive cells in future products. These routes should not be folded into a single claim about what every installation already does.

The word battery can hide that difference. A thermal store holds heat, while the useful output might be heat or electricity depending on the equipment attached. The US Department of Energy's thermal-storage assessment explains why serving a heat demand directly can avoid the conversion penalty of turning stored heat back into electricity. A factory needing heat may therefore be asking a different engineering question from a grid operator needing electrical output.

That is also why the gigawatt-hour label needs its context. Here it refers to thermal-storage capacity, not a promise to return the same quantity as electricity. Heat temperature, delivery rate and duration help determine whether a store can serve a particular process. The DOE assessment treats storage material, containment and heat transfer as parts of one system; a large energy number alone cannot specify its useful service.

For a plant manager, the story ultimately meets the production schedule. Can charging be arranged around electricity availability without interrupting the heat supply? What happens during maintenance or unusually long gaps between charges? Those are operating questions to follow as the project matures. The South Dakota announcement provides a concrete deployment to watch, while sustained performance will show how well stored heat fits the working rhythm of a factory.