South Dakota's New Thermal Storage Plant Powers Ethanol with Wind Energy
A new thermal energy storage facility has launched in Big Stone City, South Dakota. The 5 gigawatt-hour system, developed by Antora Energy in partnership with POET, will power an ethanol plant using stored heat from excess wind energy. Officials say the project will boost local jobs and support corn growers across the state. The facility was built in under a year and is already supplying power to POET’s ethanol plant. Full operations are set to begin in October. Unlike lithium batteries, thermal storage holds energy for far longer, improving grid reliability and cutting costs for consumers.
Big Stone City was chosen for its existing infrastructure, including POET’s biofuels plant, the Otter Trail Power Co. facility, and its connection to the MISO regional power grid. The project has created 300 construction jobs and will add permanent positions in the area. The system captures surplus energy from wind turbines, storing it as heat in carbon blocks. This stored energy then powers machinery at the ethanol plant. Antora earns revenue by selling the energy to POET, while also expanding sustainable electricity options in the region. The initiative has gained bipartisan backing, with support from U.S. Sens. John Thune and Mike Rounds, U.S. Rep. Dusty Johnson, and South Dakota Gov. Larry Rhoden. It is also expected to open new markets for South Dakota corn growers by increasing ethanol production demand.
The thermal storage project is now delivering power, with full capacity due in October. It will provide long-term energy stability, reduce costs, and create lasting jobs in Big Stone City. The partnership between Antora and POET marks a step toward wider adoption of sustainable energy in the region.
