This small city in rural northeastern South Dakota has established itself as an energy hub for the entire Great Plains region, and that reputation has received a big boost by landing what will be among the world’s largest energy storage projects.

In a groundbreaking project, South Dakota-based POET has partnered with Antora Energy of California to launch a thermal energy storage system adjacent to POET’s ethanol plant in Big Stone City.

The 5 gigawatt-hour thermal energy storage facility will absorb excess, low-cost energy from wind turbines that might otherwise be lost due to capacity limits on the existing power grid and store it in carbon blocks for use when needed.

Officials said the new technology will be a major economic and environmental boost to South Dakota while also pioneering the use of a new energy technology for potential use across the country and the world.

Developers cite potential benefits

Leaders of the two companies told News Watch in exclusive interviews that the storage facility – the first to be put in commercial production by Antora – will generate several benefits now and well into the future for South Dakota, including:

1. The facility will improve efficiency and increase outputs at POET’s ethanol plant in Big Stone City by providing a reliable source of sustainable energy both during times of peak and non-peak power demand, ultimately reducing consumer costs for ethanol at the gas pump.

2. It will increase production opportunities for South Dakota corn growers, who will see expanded markets for their grains to be converted into ethanol.

3. It will reduce reliance on fossil fuels by enabling greater storage of energy generated by wind, solar or other sustainable sources.

4. Construction and development of the plant has supported 300 new construction jobs in South Dakota and California and will generate new full-time employment in the Big Stone City area.

“They’re taking excess wind energy that doesn’t have a home on the grid and otherwise would be wasted, and they’re capturing that,” said Jeff Lautt, president and chief operating officer of POET in Sioux Falls, the world’s largest producer of ethanol.

“Nobody’s got a switch for the wind, so it blows when it wants to blow, yet there’s a steady demand for power that has to be met, and this system will provide for that.”

Andrew Ponec, chief executive officer of Antora Energy, was unwilling to share the total cost of the project. But a press release on the storage project noted that Antora has “catalyzed hundreds of millions in private investment in the company.”

Ponec said the majority of costs for the Big Stone project were paid through private financing, led by Grok Ventures of Australia, and not the U.S. government. He added, however, that thermal storage has received strong bipartisan support, including in the Big Beautiful Bill passed by Congress in 2025.

A May 19 press release on the project from POET and Antora included statements of support from U.S. Sens. John Thune and Mike Rounds, U.S. Rep. Dusty Johnson and South Dakota Gov. Larry Rhoden.

“America’s need for energy is continuing to rise year after year, (so) the more of that energy we can take right here at home, the better,” Rounds said in the release. ”(This) project in Big Stone City will have a real economic impact in South Dakota while also creating jobs and boosting our domestic energy production.”

A regional power hub set in a small town

Big Stone City was selected as the site for Antora’s first large-scale thermal energy storage system because of the existing POET biofuels plant and the Otter Trail Power Co. plant on the site, and due to the city’s location as a major hub on the regional Midcontinent Independent System Operator (MISO) power grid system, Ponec said.

“We’re an energy technology company, so we’re going to go to wherever there are big concentrations of energy users,” he said.

Thermal energy storage collects low-cost, off-peak energy from virtually any source – local wind turbines in this case – and stores it as heat in insulated blocks of solid carbon that reach 4,000 degrees Fahrenheit. The heat, which can be stored until needed, is then transferred into an oil that allows it to be carried to industrial users, in this instance the POET plant next door.

There, the heat is transferred to steam that powers boilers, distillers and other machinery used in production of ethanol and a host of other byproducts generated at the POET plant. The Big Stone plant produces 92 million gallons of ethanol annually, Lautt said.

Ponec likened the thermal storage process – which consists of dozens of large white metal boxes on the ground – to the operations of a giant toaster. Electricity from the outlet (energy from wind towers) is transferred to the toaster heating coils (the carbon blocks), which then generates heat to brown the bread (run machinery in the ethanol plant.)

The project uses very little water and does not create any substantial emissions, Ponec said.

To illustrate the nimble nature of thermal storage, Ponec noted that the Big Stone facility was built in less than a year. The facility is already providing power to POET’s plant and should be fully online in October.

Another type of energy storage for South Dakota

Thermal energy storage is similar to lithium ion energy storage in that both concepts seek to capture power that can be held until demand goes up and may exceed supply, thereby stabilizing the power grid and reducing costs for consumers.

But while lithium batteries store actual electricity and only for a few hours, thermal storage holds the energy as heat and can hold it for much longer periods, Ponec said.

South Dakota might soon be home to a pair of lithium battery projects, including in Codington and Brookings counties, which backers said will create new opportunities for wind and solar production in the state.

Antora makes money on the project by selling its energy to POET while opening the door to greater sustainable electricity production in the region and lowering power costs for the ethanol plant, Lautt said.

“It creates more efficiency for us, so we’re then using less natural gas to operate the facility, which makes us greener,” he said. “It really creates a win-win-win all across the footprint.”

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This story was originally published by South Dakota News Watch and distributed through a partnership with The Associated Press.

Wisconsin is more than just cheese and football. Both are a fair starting point. The towns across this midwestern state are friendly and easygoing, with distinct local character. Spring Green has riverbanks and the Frank Lloyd Wright estate. Mount Horeb still carries Norwegian roots and troll statues on Main Street. The nine towns below capture different sides of the Wisconsin experience, each with its own way of taking the pace down a notch.

Spring Green

Set along the Wisconsin River, Spring Green is a small town surrounded by deep green fields and forest. The American Players Theatre is the main draw for many visitors, an outdoor classical theater that runs Shakespeare and other plays through the summer. Architecture enthusiasts make the trip for Taliesin, the home and studio of architect Frank Lloyd Wright. Built to sit in harmony with the surrounding landscape, the roughly 800-acre estate offers guided tours that walk through Wright’s life and work. A trip to Spring Green isn’t really complete without a visit to House on the Rock, the idiosyncratic complex begun by Alex Jordan Jr. in the 1940s and famous for its elaborate themed rooms, gardens, and exhibits, including the 269-horse carousel often cited as the world’s largest indoor carousel. Out in the middle of the midwestern expanse, Spring Green captures a distinctly Wisconsin kind of curiosity.

Ephraim

A small town set in Door County, Ephraim was founded in 1853 as a sanctuary for practitioners of the Moravian Church. Those values held for a long time, and it remained the only dry municipality in Wisconsin until 2016. The shift since has helped open up the local scene, and many outdoor visitors head straight for Peninsula State Park. Hiking, biking, camping, and the open views of Green Bay are the usual reasons to go. Art lovers tend to head for Anderson Dock, the historic waterfront warehouse complex (famous for the graffiti-tradition signatures of visiting boats) that houses the Hardy Gallery. For a classic Door County stop, Wilson’s Restaurant and Ice Cream Parlor has been serving ice cream and other treats since 1906.

Cedarburg

Cedarburg sits about 20 miles north of downtown Milwaukee and was first incorporated as a village in 1885. It has since grown into a hub for the local art community. The Cedarburg Art Museum spotlights regional artists and gives a good sense of the creative side of town. Wine fans will want to visit Cedar Creek Winery, housed in an 1860s limestone mill, with tastings and a walk-through of the winemaking process. For an outdoor day, the Ozaukee Interurban Trail runs 30 miles of paved trail that connects Cedarburg with neighboring communities, with easy access for biking, walking, and birdwatching.

Bayfield

Bayfield is the gateway to the Apostle Islands National Lakeshore, with maritime history and natural draw packed into a short visit. The Lakeshore covers 12 miles of mainland coast and 21 Lake Superior islands of sandstone cliffs, old lighthouses, and sea caves. Kayaking is the locally preferred way to see them, and outfitters like Makwa Den arrange guided tours. The Bayfield Heritage Association covers the area’s past through exhibits on Native American history, maritime artifacts, and local lore. Every October, the town hosts the Bayfield Apple Festival, with a wide variety of apple-based foods, a parade, and a full slate of autumn activities.

Mineral Point

Often called a “living museum,” Mineral Point carries deep mining history that dates back to its 1827 settlement and the era of figures like Henry Dodge, later the first territorial governor of Wisconsin. The Pendarvis Historic Site preserves the lives of early Cornish miners with stone cottages and mine shafts you can walk through. The Mineral Point Railroad Museum picks up the same thread, with exhibits on the role of the railroads in 19th-century mining operations. Art lovers should add Brewery Pottery to the list, a gallery housed in a renovated brewery that displays work by local artists across multiple disciplines.

New Glarus

Known as “America’s Little Switzerland,” New Glarus celebrates its Swiss heritage with pride. The New Glarus Brewing Company, famous for its Wisconsin-only distribution and a deep lineup of Belgian-, German-, and American-style craft beers (including the flagship Spotted Cow), runs tours and tastings that pull beer fans in from across the country. The Swiss Historical Village walks visitors through how Swiss settlers lived in the 19th century, with 14 reconstructed buildings on the grounds. For an outdoor afternoon, the Sugar River State Trail covers 24 miles of hiking and biking through woods, meadows, and rolling hills.

Stockholm

Set along the banks of the Mississippi, Stockholm is a tiny Pepin County village where tradition meets creativity. The population sits at fewer than 75, which means you can expect to be treated like a long-lost family member. The Stockholm Pie and General Store is a beloved stop, with pies that have drawn national attention. Nearby Lake Pepin, the largest lake on the Mississippi, is good for boating and fishing. It is widely considered the birthplace of water skiing, after Ralph Samuelson made the first run there in July 1922. Many folks add a tour around Maiden Rock Bluff or the Little House Wayside, a reconstructed mid-1800s cabin marking the birthplace of Little House on the Prairie author Laura Ingalls Wilder.

Elkhart Lake

Elkhart Lake works for motor enthusiasts and nature lovers in equal measure. Road America, the four-mile road course just outside town, runs as one of the fastest permanent racing tracks in the country. The lake itself is good for boating, swimming, and fishing. Kayaking is common too, and you will often see a group of small boats drifting across the water. The nearby Kettle Moraine State Forest opens up hiking, biking, and camping. The Throttlestop Motorcycle Museum keeps a rotating collection of more than 200 antique bikes alongside cars and vintage engines.

Mount Horeb

Rooted in Norwegian heritage, Mount Horeb pairs history and outdoor access in a single short visit. The region was originally home to the Ho-Chunk nation, and European settlers later named the site after a biblical mountain. The Cave of the Mounds, a National Natural Landmark since 1988, opens up tunnels of limestone formations on guided tours. Mount Horeb’s main street, known as the “Trollway,” is lined with troll statues that give the town its quirky calling card. The Grumpy Troll Brew Pub, a beloved local brewery, serves a variety of craft beers, the consumption of which is arguably the official state sport of Wisconsin.

A State Worth Slowing Down For

These towns are more than dots on the map. They are living, working places that carry old traditions forward while making room for what comes next. Whether the draw is the Swiss heritage of New Glarus, the mining history of Mineral Point, the maritime feel of Bayfield, or the racing weekends at Elkhart Lake, each town shows a different side of Wisconsin life. Taken together, the nine sketch out a state as varied as it is welcoming.