Antora Energy's 5 GWh thermal battery system at a South Dakota ethanol plant is now drawing intense… | Clean Energy Briefing — May 22, 2026

TODAY'S LEAD: Antora Energy's 5 GWh thermal battery system at a South Dakota ethanol plant is now drawing intense industry attention as one of the largest energy storage installations on the planet — a bold proof of concept that could reshape how heavy industry decarbonizes process heat. Meanwhile, Texas continues to cement its dominance as the nation's battery storage capital, with nearly 1.8 GWh of new project activity announced or advancing in a single day.

KEY DEVELOPMENTS

Antora Commissions Massive 5 GWh Thermal Storage in South Dakota: Antora Energy's 50 MW thermal battery system at POET's Big Stone City bioprocessing facility uses over 200 superheated carbon blocks to store excess wind power, replacing natural gas for industrial heat in what ranks among the world's largest energy storage deployments. Read More: PV Magazine USA.
Spearmint Secures $450M for 600 MWh Texas Battery: Spearmint Energy locked in financing for its 300 MW / 600 MWh Red Egret battery energy storage project in Texas, adding to the state's rapidly growing grid-scale storage fleet. Read More: Energy Storage News.
Enbridge, Meta Partner on $1.2B Wyoming Solar-Storage Project: The 365 MW solar and 200 MWh battery storage Cowboy Project near Cheyenne will power Meta data centers, with operations expected by late 2027. Read More: Utility Dive.
GridStor Acquires 796 MWh Colorado Battery Project: GridStor purchased the Birdseye BESS in Adams County, Colorado, while Hull Street Energy moves to acquire FirstLight's 1.4 GW portfolio including New England's largest pumped storage facility. Read More: PV Magazine USA.
States Face Regulatory Bottlenecks on Solar-Plus-Storage Interconnection: A new scorecard from the Interstate Renewable Energy Council and Vote Solar finds most states have outdated interconnection rules that are choking distributed solar and storage deployment. Read More: PV Magazine USA.

Solar & Storage

The sheer volume of battery storage activity across the United States this week is staggering, and Friday's news only reinforces the trend. In Texas — already the undisputed leader in grid-scale energy storage — Spearmint Energy's $450 million financing close for its 300 MW / 600 MWh Red Egret project signals that capital markets remain eager to back large BESS deployments in ERCOT, where volatile wholesale prices create strong merchant revenue opportunities. That deal lands alongside Frontier Power USA's from Bimergen Energy and the completion of GridStor's 220 MW / 440 MWh in Galveston County, which came online by its November 2025 deadline despite early technical hurdles. Together, these projects represent well over 1.5 GWh of storage capacity either newly operational, financed, or acquired in the Lone Star State alone. Read More: acquisition of a 480 MWh battery portfolio, Hidden Lakes Reliability Project.

But the day's most striking story may be unfolding 1,200 miles north, in Big Stone City, South Dakota. Antora Energy's 50 MW / 5 GWh thermal energy storage system at POET's bioprocessing facility is now commissioned, using more than 200 superheated carbon blocks to absorb surplus wind energy and convert it to industrial process heat — at one of the nation's largest ethanol producers. At 5 GWh, the installation dwarfs conventional lithium-ion projects and demonstrates a storage duration measured in days, not hours. Grok Ventures backed the project as sole external investor under a long-term heat offtake agreement, a financing structure that could become a template for industrial decarbonization projects where thermal demand — not electricity — is the end product. For an industry that has focused overwhelmingly on electrochemical batteries, the Antora deployment is a reminder that the energy storage universe is far broader than lithium-ion. Read More: displacing natural gas.

Meanwhile, the consolidation wave in the storage sector continues to accelerate. GridStor, fresh off completing Hidden Lakes in Texas, has in Adams County, Colorado, with construction slated for 2027 and commercial operations in 2028. In a separate and arguably even larger transaction, Hull Street Energy signed an agreement to acquire FirstLight USA's entire 1.4 GW portfolio, headlined by the 1,168 MW Northfield Mountain pumped hydro facility in Massachusetts — New England's largest energy storage asset. That deal underscores growing investor appetite not just for new-build battery projects but for legacy storage infrastructure that provides long-duration grid reliability. Read More: acquired the 199 MW / 796 MWh Birdseye BESS project.

On the solar side, the Enbridge-Meta partnership on the $1.2 billion continues a pattern of hyperscale tech companies driving utility-scale solar development to feed insatiable data center power demand. The 365 MW solar project paired with 200 MWh of battery storage is expected online by late 2027, adding to the growing list of corporate-backed renewable energy projects in the Mountain West. At the other end of the scale spectrum, innovation is happening at the neighborhood level: in a U.S. urban neighborhood, demonstrating how creative form factors can squeeze generation into space-constrained commercial settings. And in Ann Arbor, Michigan, a new not-for-profit utility is with no upfront costs — a model that could lower barriers to distributed solar adoption in communities where high installation costs have historically been a dealbreaker. Read More: Cowboy Project in Wyoming, Sunzaun installed what it calls the first vertical bifacial solar fence, offering rooftop solar with battery storage for $600 annually.

Wind Energy

Wind energy's role in today's headlines is indirect but significant. The Antora thermal storage project in South Dakota is fundamentally a wind integration play — absorbing excess generation from the region's robust wind fleet and converting it to useful heat, effectively solving curtailment problems while decarbonizing industrial processes. This approach could prove particularly valuable across the Great Plains and Upper Midwest, where wind penetration levels routinely push generation beyond what the grid can absorb during off-peak hours. If the POET deployment performs as designed, expect other ethanol producers and heavy industrial operators in wind-rich states to explore similar arrangements.

Policy & Markets

A new puts hard data behind what developers have long complained about: most states have interconnection procedures that were designed for a simpler grid and are now creating serious bottlenecks for distributed solar-plus-storage projects. The scorecard evaluates state-level regulatory frameworks across 56 criteria in 10 operational categories, and the findings are sobering. At a moment when federal clean energy policy under the Trump administration remains focused on fossil fuel production and potential rollbacks to Inflation Reduction Act incentives, the burden of enabling clean energy deployment increasingly falls on state-level regulatory reform — making these interconnection rules a critical choke point. Read More: report from the Interstate Renewable Energy Council and Vote Solar.

In Massachusetts, that tension between state ambition and policy execution is playing out in real time. The over how to reduce residents' energy bills, with disagreements centering on the best mechanisms to deliver relief without undermining clean energy commitments. The debate carries particular weight in a state that houses FirstLight's Northfield Mountain facility — soon to change hands — and where ratepayers are already feeling the cost pressures of grid modernization and renewable energy integration. Read More: state's House and Senate remain at odds.

Globally, IRENA this week proposed a of total final energy consumption by 2035, requiring a staggering 18.4 TW of global renewable capacity. The agency noted that 2.5 TW of solar, storage, and wind projects are already sitting in interconnection queues worldwide — a figure that reinforces just how central the permitting and interconnection challenges identified in the IREC report are to the entire global energy transition. Read More: target of 35% electrification.

LOOKING AHEAD

Texas BESS Pipeline Surges: With multiple developers — including — advancing battery projects across Texas, California, Colorado, and Georgia, watch for ERCOT interconnection queue data to reveal the true scale of near-term storage buildout. Read More: OCI Energy, MN8 Energy, GridStor, and Grenergy.
Thermal Storage Scale-Up: The success or failure of Antora's 5 GWh system at POET will be closely watched by industrial operators considering thermal batteries as a natural gas replacement — a market potentially worth tens of gigawatt-hours nationally.
Massachusetts Energy Bill Negotiations: As House and Senate negotiators work to reconcile competing approaches to energy cost relief, the outcome could set precedent for how other Northeastern states balance affordability with decarbonization mandates.

TODAY'S QUICK ANSWERS

Q: What does Antora's 5 GWh thermal battery mean for industrial decarbonization?

A: It proves that long-duration thermal storage can replace natural gas for process heat at industrial scale — a market segment that electrochemical batteries cannot economically serve. If POET's facility performs as expected, ethanol plants, refineries, and chemical manufacturers across wind-rich states could adopt similar systems, potentially opening a multi-billion-dollar market for thermal storage that sidesteps the lithium-ion supply chain entirely.

Q: Why should developers worry about state interconnection rules right now?

A: With federal clean energy policy uncertain under the Trump administration, state-level regulatory frameworks are becoming the primary enablers — or blockers — of distributed solar and storage deployment. The IREC scorecard shows most states are failing, meaning developers face months or years of delays even where project economics are strong. Companies should prioritize markets with modernized interconnection procedures or risk stranded development capital.

Q: What's driving the battery storage acquisition frenzy?

A: Investors are racing to lock in storage assets before competition intensifies further, particularly in ERCOT where merchant battery revenues have proven lucrative. GridStor's dual moves — completing a Texas BESS while acquiring a Colorado project — and Hull Street's grab of FirstLight's 1.4 GW pumped hydro portfolio signal that both new-build and legacy storage assets are being valued as essential grid infrastructure, not speculative bets.

THE BOTTOM LINE: The U.S. energy storage sector is expanding on every front — from 600 MWh lithium-ion batteries in Texas to a 5 GWh thermal system in South Dakota to a 1.4 GW pumped hydro acquisition in New England — and the companies positioning themselves across these diverse technologies and geographies today will own the grid flexibility market of the next decade.