Supercapacitors, tax credits, and tribal microgrids are quietly reshaping US green energy storage—and showing businesses and communities how to fund and control clean power.
As of late 2025, three numbers tell you where green technology is heading in the US energy market:
- 1 million: the number of charge cycles Maxwell’s supercapacitors can endure.
- US$46 million: the value of Fullmark Energy’s latest tax credit transfer.
- US$500–600: what some Colville Reservation residents pay each month for unreliable power.
Those numbers aren’t just trivia. They mark a turning point for green energy storage, financing, and energy sovereignty—exactly the areas where businesses, utilities, and communities are fighting to decarbonize without sacrificing reliability or profitability.
This post, part of our Green Technology series, looks at three recent US developments and what they really mean:
- Clarios acquiring Maxwell Technologies and what that signals for supercapacitors.
- Fullmark Energy’s US$46 million Investment Tax Credit (ITC) transfer and the new playbook for funding battery storage.
- OATI and the Colville Tribes’ microgrid partnership and the rise of tribal energy sovereignty.
If you’re building, investing in, or buying into clean energy systems, these stories point to where the opportunity is heading—and how to position yourself now.
1. Why Maxwell’s Supercapacitors Still Matter in a Battery World
Maxwell Technologies changing hands again—this time to Clarios—might look like just another corporate shuffle. It isn’t. It shows how high-power energy storage is becoming central to both automotive and grid applications.
Clarios will run Maxwell as an independent US-based unit, folding ultracapacitor-based energy storage into a portfolio that’s already strong in low-voltage automotive solutions. That combination matters.
Supercapacitors vs batteries: different tools, different jobs
Here’s the thing about supercapacitors: they’re terrible long-term energy tanks, but unbeatable sprinters.
- They charge and discharge almost instantly, which makes them perfect for:
- Smoothing sudden demand spikes on the grid
- Capturing short bursts of regenerative braking energy
- Backing up sensitive electronics and data centers
- They can endure up to 1 million charge cycles, far beyond typical lithium-ion batteries.
- They operate from -40°F to 149°F (-40°C to 65°C) with no maintenance and no fire-risk safeguards.
So where do they fit into green technology? Think of them as shock absorbers for your energy system:
- On the grid: handling fast frequency regulation and transient events so batteries don’t get hammered.
- In vehicles: supporting start-stop systems, cold starts, and high-power events that kill batteries early.
- In industrial and military systems: powering high-pulse loads and mission-critical systems where failure isn’t an option.
From Tesla to Clarios: what changed?
Tesla’s story with Maxwell is a useful reminder of how energy tech evolves:
- 2019 – Tesla buys Maxwell, largely for its dry battery electrode technology.
- 2021 – Tesla sells Maxwell’s ultracapacitor business and brand to Ucap Power but holds on to the dry electrode process.
- 2025 – Clarios acquires Maxwell’s ultracapacitor business from Ucap Power.
Tesla effectively said: we want the battery manufacturing breakthrough, not the supercapacitor product line. Clarios is saying the opposite: we want the supercapacitor platform and the customer relationships in data centers, grid, military, and industrial sectors.
For anyone working in energy storage strategy, the message is clear:
Batteries aren’t the only green storage technology that matters. High-power devices like supercapacitors are key to making those batteries last longer and grids run smoother.
Practical implication: think hybrid storage, not either/or
Most companies get this wrong. They try to choose batteries vs supercapacitors instead of designing hybrid storage architectures that use both.
If you’re planning new systems in 2026–2030, start from this principle:
- Use batteries for energy (hours of storage, bulk shifting)
- Use supercapacitors for power (seconds to minutes, spikes and support)
That mix reduces battery degradation, improves round-trip performance, and makes it easier to integrate AI-driven control systems that orchestrate different assets in real time.
2. Fullmark’s US$46M ITC Transfer: How Storage Projects Actually Get Built
The Fullmark Energy story might be the most important one in this roundup if you care about scaling green infrastructure.
Fullmark just completed a US$46 million Investment Tax Credit transfer tied to its operational 125MW/290MWh Redwood BESS portfolio in California. That includes:
- San Jacinto BESS – 65MW/130MWh in Banning (COD in November 2025)
- Johanna BESS – 20MW/80MWh in Santa Ana (operational since 2021)
- Desert-Carris BESS – 20MW/40MWh in Palm Springs
- Ortega BESS – 20MW/40MWh in Lake Elsinore
Together, the 2025 projects alone added 105MW of new capacity to Southern California Edison’s distribution system.
Why the ITC transfer is a big deal
Under the Inflation Reduction Act (IRA), clean energy projects can access an ITC and then transfer that credit to a buyer—in this case, an industrial-sector entity—for cash.
That’s exactly what Fullmark did:
- They reached commercial operations across the portfolio.
- They transferred US$46 million in tax credits to a third-party buyer.
- They converted that into capital they can reuse for new storage development.
For developers and investors, this is the emerging playbook:
- Secure long-term offtake or grid contracts.
- Build and commission the storage projects.
- Monetize tax credits through a structured transfer.
- Recycle capital into the next wave of projects.
Chris McKissack, Fullmark’s CEO, called the ITC a strength of the IRA because it’s “creating tangible pathways for infrastructure investment in American communities.” I agree with that framing. This isn’t abstract policy anymore; it’s 125MW of real batteries sitting on California’s grid.
The One Big Beautiful Bill Act: constraint and catalyst
Of course, there’s a twist: the One Big Beautiful Bill Act tightens the rules on where components can come from if you want those tax credits.
- Starting 2026: at least 55% of project costs must come from non-prohibited foreign entities.
- By 2030 and beyond: that threshold rises to 75%.
This will push storage developers to:
- Build resilient, domestic or allied supply chains for batteries, inverters, and control systems.
- Work closely with manufacturers like Clarios, Eos, and others who can demonstrate compliant sourcing.
- Use AI tools for supply chain planning—modelling different sourcing scenarios against IRA and OBBA rules.
I’ve found that teams who get ahead of these rules aren’t just compliant—they’re cheaper to finance. Lenders and tax credit buyers heavily discount projects with supply chain risk they don’t understand.
Actionable takeaways for storage developers and buyers
If you’re on the developer side:
- Start ITC transfer structuring as early as possible; don’t wait for COD to think about buyers.
- Build a compliance data room: BOM breakdowns, supplier declarations, country-of-origin data.
- Use AI-driven financial models to test different tax credit scenarios (direct pay vs transfer, timing, discount rates).
If you’re an energy buyer or large industrial off-taker:
- Ask specifically whether your future BESS capacity has a monetized ITC layered into the capital stack.
- Negotiate contracts that share some of that economic benefit in exchange for longer or more flexible offtake.
This is where green technology, policy, and finance come together: smart structuring is what turns climate ambition into actual steel-in-the-ground—and batteries-in-the-field.
3. OATI & Colville Tribes: Microgrids as a Path to Energy Sovereignty
The most human story here comes from Washington State, where the Confederated Tribes of the Colville Reservation and Open Access Technology International (OATI) are working together on a series of microgrids.
This isn’t just about clean electrons. It’s about energy sovereignty and basic reliability.
Residents on the Colville Reservation regularly face:
- Frequent outages, especially during winter storms and extreme heat
- Monthly bills of US$500–US$600 for power
- Multiple utilities serving the area at different service levels, making coordination difficult
The partnership is built on a simple principle:
Energy sovereignty is the right of tribes to produce, deliver, and manage energy on their own lands.
What the microgrid program actually includes
With support from federal and state grants, OATI will deploy its GridMind platform across several sites:
-
Nespelem HQ Campus (Lucy F. Covington Government Centre)
- Rooftop solar PV
- Battery storage
- EV charging stations
- Microgrid controls
- Future expansion into a full campus resiliency hub
-
Paschal Sherman Indian School (PSIS)
- A community microgrid supporting both campus operations and broader community resilience
-
Keller and Inchelium Districts
- Additional distributed energy resources (DERs)
- Microgrid infrastructure to firm up local power
Future phases may connect gaming operations and potential data centers, leveraging tribal-owned utility and telecom assets.
This matters because microgrids like these are multi-layer tools:
- They keep critical services (healthcare, housing, commerce, schools) powered during outages.
- They lower long-term energy costs by using local solar and storage.
- They open new revenue streams, like participating in regional energy markets.
The wider trend: tribal lands as clean energy leaders
The Colville project isn’t happening in isolation. You’ve got:
- Eos & Faraday Microgrids deploying a 3MW/15MWh zinc hybrid system on tribal land in California.
- Paired Power and PHNXX partnering under the Alliance for Tribal Clean Energy to deliver modular microgrids to Native American and Aboriginal communities.
There’s a pattern here:
- Tribes control vast land areas with strong solar and wind resources.
- They often sit at the edge of legacy grid infrastructure, where reliability is worst.
- They have governance structures that can move faster than some state-level processes, especially when tied to sovereignty goals.
For green technology providers, this is an opportunity that’s both ethical and commercial:
- Work with tribal governments as strategic partners, not just customers.
- Co-design systems that reflect local priorities: jobs, cultural sites, environmental protection.
- Use AI-enabled microgrid controls (like GridMind and similar platforms) to coordinate solar, batteries, and demand response in real time.
As Jarred-Michael Erickson, Chairman of the Colville Tribes, put it, the goal is not just to keep the lights on, but to unlock new economic opportunities. That’s exactly where green technology should be pointed.
4. How These Stories Fit the Bigger Green Technology Picture
Taken together, Maxwell/Clarios, Fullmark, and the Colville–OATI partnership sketch out the next phase of green technology in the US:
- Storage is becoming more specialized: supercapacitors for power, batteries for energy, zinc hybrids for resilience.
- Financing is more sophisticated: ITC transfers, compliance thresholds, and policy-driven capital stacks.
- Ownership is more distributed: tribes, communities, and non-utility players are building and operating their own clean energy assets.
If you’re planning your own strategy for 2026 and beyond, here are concrete moves that work:
- Design with multiple storage technologies in mind.
- Use supercapacitors or other high-power devices to protect and enhance battery fleets.
- Bake policy into your business model, not as an afterthought.
- Model your projects with and without IRA/ITC benefits and OBBA constraints.
- Partner where the need is highest and the impact is clearest.
- Tribal lands, remote communities, and overloaded urban feeders are prime candidates for smart microgrids.
- Use AI where it actually moves the needle.
- Grid orchestration, forecasting, asset optimization, and supply chain planning are all AI-ready today.
Green technology isn’t just about cleaner electrons—it’s about who controls them, who pays for them, and who benefits from them.
If you’re exploring storage projects, microgrids, or clean energy financing and want to understand what’s realistically possible in 2026–2030, this is the moment to start architecting your approach. The policies are live, the technologies are bankable, and the use cases—from California suburbs to Washington tribal lands—are already running.
FAQ: Quick Answers for Decision-Makers
Q: Where do supercapacitors make the most sense in green energy projects?
A: They’re ideal anywhere you need high power for short durations: grid stability, peak shaving support, cold starts, industrial pulses, and as a buffer in front of batteries to reduce degradation.
Q: How do ITC transfers help get battery storage projects built?
A: Developers can sell the tax credit to a buyer and use the cash to reduce project debt, improve returns, and fund the next project—without waiting years to use the credit on their own tax bill.
Q: Why are tribal microgrids getting so much attention?
A: Because they sit at the intersection of reliability, justice, and economics—delivering cleaner power, local control, and new revenue streams in places that have often been last in line for infrastructure.