GM bets big on sodium-ion batteries for grid-scale storage
KEY DEVELOPMENTS
- Federal Judge Restores 5% Safe Harbor for Solar, Wind Tax Credits: A ruling ahead of the July 4 deadline reinstates the rule allowing renewable energy projects to lock in federal tax credits by spending 5% of project costs, a lifeline for developers racing to qualify under uncertain IRA provisions. Read More: PV Tech.
- GM Partners with Peak Energy on Sodium-Ion Grid Storage: General Motors will manufacture sodium-ion battery systems for utilities and data centers, deploy 7.2 MWh of second-life EV packs at its Michigan facility, and begin LFP battery production within a month — projecting over $3 million in electricity cost savings. Read More: PV Magazine.
- EDP Renewables Commissions 200 MW Arizona Battery Project: The Flatland Energy Storage system in Coolidge delivers 800 MWh to Salt River Project, enough to serve roughly 44,500 homes in central. Read More: Arizona, Solar Power World.
- Zelestra Signs 180 MW Texas Solar PPA with Meta: The Palmera Solar Plant in Freestone County adds to Meta's corporate renewable procurement in , expanding an existing partnership between the two companies. Read More: Texas, PV Tech.
- Permitting Delays Threaten to Flatten U.S. Solar Growth: Despite 7.8 GW of new solar capacity added in Q1 2026 — with solar and storage making up 91% of new grid additions — analysts warn installation numbers could plateau over the next five years as permitting backlogs choke the pipeline. Read More: Solar Power World.
Solar & Storage
The safe harbor ruling, which we flagged Monday when the court first vacated Notice 2025-42, now has sharper teeth and a tighter timeline. The restored 5% rule means developers who spend at least 5% of a project's total cost before the July 4 deadline can still qualify for Investment Tax Credits and Production Tax Credits under prior terms. For any company with steel on the ground or equipment on order, the next 24 days are a sprint. The practical effect: projects that looked financially marginal in May just got their economics back, provided sponsors can document spending fast enough.
That ruling arrives alongside a sobering forecast. The U.S. added , and solar plus storage accounted for 91% of all new generating capacity connected to the grid during the quarter. But analysts now expect permitting bottlenecks — not demand or financing — to be the binding constraint. Local zoning fights, interconnection queue delays, and environmental review timelines could keep annual installation numbers essentially flat through 2031, even as utility and corporate offtake appetite remains strong. Read More: 7.8 GW of new solar capacity in Q1 2026.
Case in point on the demand side: Zelestra's in Freestone County, Texas, locked in a long-term PPA with Meta, expanding an existing relationship between the Spanish developer and the tech giant. Data center operators like Meta continue to sign utility-scale solar contracts at a pace that far outstrips the industry's ability to get projects permitted and built. Separately, Revolve Renewable Power , adding mid-stage projects to its pipeline — a bet that the permitting logjam will eventually clear and early-stage assets will appreciate. Read More: 180 MWdc Palmera Solar Plant, acquired a 125 MW U.S. solar development portfolio.
In , community solar found a new use case. Common Energy and Trinity Services, a nonprofit serving people with intellectual and developmental disabilities, are partnering on across greater Chicago. The arrays will deliver energy bill credits to more than 120 Trinity Services locations. It's a model that other nonprofits with large facility portfolios — healthcare systems, housing authorities — will watch closely, particularly in states where community solar subscriber rules allow institutional anchors. Read More: Illinois, five projects totaling 16 MW.
Grid-scale storage, meanwhile, is moving from niche to anchor. EDP Renewables and Salt River Project in Coolidge, Arizona — a 200 MW / 800 MWh standalone battery system with four-hour duration. At 800 MWh, Flatland is among the larger standalone systems operating in the West, and its commissioning strengthens Arizona's position as a storage hub alongside California and Texas. Salt River Project, the public utility serving the Phoenix metro area, will use the system to manage peak demand across central Arizona, displacing gas peakers during the brutal summer afternoons when air conditioning loads spike. Read More: brought online the Flatland Energy Storage project.
GM's entry into stationary storage could reshape the competitive field further. The automaker's targets sodium-ion chemistry — cheaper than lithium-ion, free of cobalt and nickel supply chain risks, and well suited for long-duration applications where energy density matters less than cost per kilowatt-hour. GM also plans to deploy 7.2 MWh of second-life EV battery packs at its Michigan plant, a proving ground for the circular-economy pitch the company is making to utilities and data center operators. LFP battery production through its joint venture with LG Energy Solution is set to begin within a month. For storage developers, the question is whether GM's manufacturing scale can compress battery costs faster than the current crop of dedicated storage suppliers. Read More: partnership with Peak Energy.
GM is also enabling for EV owners, allowing drivers to sell excess battery capacity back to the grid. The distributed storage potential is enormous on paper — every parked EV becomes a two-way asset — but grid operators and regulators have been slow to create tariff structures that make V2G economically attractive at scale. Read More: vehicle-to-grid power sales.
Policy & Markets
Transmission remains the unglamorous chokepoint. ITC Michigan is seeking public comment on a proposed 50-mile, 765-kilovolt line running from Eaton County to Livingston County, part of MISO's. Landowner opposition is already vocal. The project needs Michigan Public Service Commission approval, and the public input phase will test whether state regulators can balance reliability imperatives against property rights concerns. For renewable developers with projects in the MISO queue, this line — and others like it — determines whether generation can actually reach load. Read More: $21.8 billion Midwest energy reliability plan.
The broader policy picture remains fractured. The Trump administration's efforts to roll back IRA incentives through Treasury guidance have been partially checked by the courts, as this week's safe harbor ruling demonstrates. But legislative uncertainty in Congress and the administration's continued expansion of the Chinese military-linked company list — flagged in Monday's briefing — are adding friction to supply chains and project economics simultaneously. Developers are managing a two-front challenge: securing tax equity before rules change again, and sourcing panels and cells that won't trigger trade restrictions.
LOOKING AHEAD
- July 4 Safe Harbor Deadline: Solar and wind developers have less than 25 days to document 5% project spending and lock in federal tax credit eligibility under the restored safe harbor rule — expect a wave of equipment purchase orders and construction mobilization notices.
- GM LFP Battery Production Launch: General Motors says LFP battery manufacturing through its LG Energy Solution joint venture begins within a month at Michigan facilities; the first customer contracts and pricing will signal whether an automaker can undercut pure-play storage suppliers.
- ITC Michigan Transmission Public Comment: Landowner opposition to the 50-mile, 765-kV line in Michigan's Eaton and Livingston counties could set a precedent for how MISO's $21.8 billion reliability buildout navigates local resistance across the Midwest.
TODAY'S QUICK ANSWERS
Q: What does GM's sodium-ion push mean for grid storage pricing?
A: Sodium-ion cells avoid the lithium, cobalt, and nickel supply chains that have driven battery cost volatility. If GM can manufacture at automotive scale — tens of gigawatt-hours annually — it could push grid storage system prices well below $200/kWh within two to three years, pressuring incumbents like Fluence, Tesla, and BYD on price while sidestepping Trump administration restrictions on Chinese battery imports.
Q: Why should developers treat the July 4 safe harbor deadline as a hard cutoff?
A: The court restored the 5% spending rule, but another challenge or new Treasury guidance could narrow the window again. Projects that can document qualifying expenditures before July 4 gain durable tax credit eligibility regardless of future regulatory changes — those that miss it face real risk of losing credits worth 30% or more of project cost.
Q: Can U.S. solar growth actually go flat with this much demand?
A: Demand from utilities and corporate buyers like Meta is not the bottleneck. Interconnection queues now average four to five years, and local permitting fights are adding 12–18 months in many jurisdictions. The 7.8 GW installed in Q1 2026 reflects projects that cleared those hurdles years ago. What's in the pipeline today may not break ground until 2029 or later, which is why analysts see a plateau even as 91% of new capacity additions are solar and storage.
THE BOTTOM LINE: The courts gave solar and wind developers a narrow reprieve on tax credits, but permitting delays — not policy or demand — are emerging as the hard ceiling on U.S. clean energy growth, and the companies that solve the buildout bottleneck, whether through battery manufacturing scale like GM or transmission construction like ITC Michigan, will define the next phase of the transition.