Episode 5: Grid-Forming and Grid-Following Technologies in Energy Storage

(Editor’s note: The following transcript has been edited for clarity.)

Episode 5: Grid-Forming and Grid-Following Technologies in Energy Storage | 5.8.25

Shellka Arora-Cox: Welcome to Resilience, the vodcast dedicated to resilience in the energy sector. I’m your host, Shellka Arora-Cox, a partner at Pillsbury Winthrop Shaw Pittman. Joining me today is Amit Barnir, vice president for network infrastructure at Zenobē in the United States. Amit and I will be talking about the roles of grid-forming and grid-following technologies in modernizing the energy grid. Amit, welcome.

Amit Barnir: Thank you for having me. It’s a pleasure to be here today.

Arora-Cox: It’s great to have you. Let’s begin with your journey. How did you land in your current position at Zenobē? And what motivated your focus on grid resilience?

Barnir: It’s been an interesting journey. I started out in the retail energy space during college with Hess Corporation, which had a large energy marketing division focused on delivering power and natural gas to major end users like Anheuser-Busch and Pfizer. That early exposure opened my eyes to the complexity of how power gets from generation to end users.

From there, I moved into Hess’ electric pricing division, where I developed a deeper understanding of the operational side of energy delivery. That role sparked a long career in retail energy, including six years at Great Eastern Energy in New York, where I oversaw electric operations and power trading across PJM, New York ISO and ISO New England. That experience gave me a broad perspective on everything from pricing mechanics and tariffs to billing and power procurement. During that time, I spent a lot of time on energy compliance work, engaging with solar developers and dealing with renewable energy credit obligations. That exposure helped me see the shift taking place in the industry—from simply delivering power reliably and cost-effectively to enabling decarbonization and net-zero energy. ESG goals were gaining traction, and it felt like a natural time to move from the crowded, commoditized retail energy space into the renewable sector. That’s when I joined Kearsarge Energy. They were a solar developer venturing into energy storage and quickly realized that storage is fundamentally different—it’s not passive like solar, where you build a project, and the sun does the rest. Storage requires real-time management. My background in wholesale energy supply and trading aligned well with that challenge, and I led their energy storage division for four years. We built and operated multiple projects across the Northeast, mostly in the one-to-five-megawatt range, under programs like NY-VDER and Massachusetts SMART. It was a hands-on experience in developing, operating and trading storage assets. But I wanted to take things to a larger scale, and that’s what drew me to Zenobē. I joined in January 2023 to help launch their U.S. energy storage platform, just as the Inflation Reduction Act was expanding possibilities for standalone storage. Zenobē offered a unique opportunity—a company with deep expertise in the UK, spanning transmission-scale infrastructure, electric vehicle fleet solutions and second-life battery applications. They were already thinking holistically about the battery life cycle and its role in both mobile and stationary energy systems. That vision aligned with where I wanted to go professionally.

Arora-Cox: That’s quite a journey. You mentioned Zenobē’s impact in the UK. How is the company shaping energy infrastructure here in the United States?

Barnir: Zenobē’s work in the UK has been transformative, especially in grid-forming technology. They spent years collaborating with regulators and transmission operators to demonstrate how energy storage could provide more than just arbitrage or backup—it could actively support the grid. Those years of advocacy and system validation helped change the narrative around what storage can do.

We’re bringing that same mindset to the United States, though the landscape here is more complex. Unlike the UK, which has a single grid operator and unified regulatory structure, the United States has dozens of ISOs and utility commissions, with overlapping jurisdictions and policies. That’s why we’ve built dedicated advocacy and regulatory teams to engage stakeholders at every level—from local utilities to state regulators to national ISO forums.

Our goal is to reframe the role of energy storage. We believe it should be an integral part of grid planning, not just an add-on. That means deploying grid-forming solutions that increase system flexibility and reliability, especially as we integrate more renewables. We’re here to modernize the grid using a proven playbook from the UK, while tailoring our strategy to the regulatory diversity of American markets.

Arora-Cox: Let’s focus on that. What is grid-forming technology, and why is it so important to the energy transition?

Barnir: Grid-forming technology enables inverter-based resources—like batteries—to provide essential grid services that were traditionally delivered by synchronous generators. In a grid-following system, the inverter tracks the voltage and frequency already present on the grid. If there’s a disturbance—say, a voltage dip or a frequency event—these inverters try to follow the grid’s conditions, but once those conditions fall outside of a narrow operating band, they may no longer be able to respond effectively. In extreme cases, this can cause them to trip offline. That’s especially problematic when you have many such resources on the grid: one trips, the disturbance worsens, others follow, and it can cascade into a blackout.

Grid-forming inverters, on the other hand, do the opposite. They set their own voltage and frequency references. They can respond quickly and stabilize the system during disturbances, effectively “forming” the grid instead of just following it. In a voltage or frequency event, a grid-forming system can help lead the grid back to stability by injecting the right signals and supporting system parameters. In short, they don’t just follow the grid—they help create and support it. That makes them incredibly important for resilience, especially as we bring on more variable renewables like wind and solar.

Arora-Cox: So, do we need both technologies on the grid long-term?

Barnir: I think there’s always going to be a mix of both. Grid-forming systems require some dispatchability—you need the ability to put electrons back on the grid, which doesn’t always mean traditional generation. There’s real power and reactive power; the latter supports grid functions like voltage, frequency and inertia. But you still need a reliable energy source behind it. Since wind and solar aren’t always available, battery storage is, in my view, the best fit for grid-forming applications.

Arora-Cox: The United States is a patchwork of regulatory regimes. What opportunities and challenges are you seeing across different states?

Barnir: The regulatory environment in the United States is incredibly fragmented. In the UK, there’s one grid operator and a single regulatory regime, which essentially flows down into a clear and manageable set of rules and regulations. Here in the United States, we have 50 states with different goals, overlapping ISOs and a wide range of stakeholders. That complexity creates gray areas when it comes to who has authority over grid innovation.

When we think about grid-forming adoption in the United States, we consider it on multiple levels: at the ISO level and at the state level. Take New York, for example. It’s a single-state ISO with a unified regulatory framework. But in PJM, you have 13 states, each with its own rules and regulators, which makes coordinated progress much more difficult. That said, we are seeing leadership emerge. Hawaii, for instance, deployed one of the world’s leading grid-forming battery projects. And ERCOT in Texas is actively setting rules for grid-forming requirements. ERCOT is well-positioned to do so—once again, a single-state ISO and single-state regulator. We believe there will be grid-forming standards, requirements for new energy storage to be grid-forming. These are promising signals that some regions are starting to move the needle.

Arora-Cox: How does Zenobē engage with utilities and regulators to advance these technologies?

Barnir: Advocacy is a major part of our strategy. We have team members dedicated to regulatory engagement. We focus on educating regulators directly and believe there needs to be mandates coming from regulators. Historically, they’ve relied on transmission owners and utilities to propose solutions. We’re encouraging regulators to take the lead—to ask not just what the utilities want, but what’s possible with newer technologies. For example, utilities often respond to reliability issues by proposing to build more wires. That’s expensive and inflexible, and also single use. Grid-forming batteries can offer multiple services—generation, resilience and ancillary support. You don’t need to pay for separate assets to do all that. One system can do it more efficiently.

Arora-Cox: What kind of feedback are you getting, especially from places like ERCOT?

Barnir: It’s been a mixed bag. ERCOT took a firm stance by mandating grid-forming requirements. We’ve raised concerns that if developers are required to deliver grid services without compensation, they’ll naturally avoid challenging areas and go where compliance is easiest. We believe compensation is key. If a project is providing a service—like frequency control—it should be paid for that service. That ensures technologies are deployed where they’re needed most and in the most effective way.

Arora-Cox: Let’s talk about the tech itself. Are you seeing any promising advancements?

Barnir: Interestingly, the inverter technology hasn’t changed much. What’s evolving is how we model, monitor and verify performance. Grid-forming has existed for years, but now we can prove it works with much more precision. What’s challenging is that when grid-forming is working properly, grid events don’t happen. So how do you verify something that prevents a problem before it occurs? That’s where new tools and methodologies are coming in.

Arora-Cox: As we close? What keeps you energized in this fast-changing space?

Barnir: This industry moves incredibly fast. In six years, I’ve seen technologies rise and fall. Long-duration energy storage is a great example. Chemistries that seemed promising six years ago are being replaced by newer, more scalable options. What keeps me engaged is the constant change. I’m not trying to pick a winner today—I’m focused on understanding where the industry is going in 10, 20 or 30 years. That long-term thinking keeps me motivated.

Arora-Cox: I’ve heard you’re passionate about cooking. Is there a connection between that and your work on grid-forming?

Barnir: There definitely is on the patience side. Grid-forming technology is like cooking a multiday dish that takes 24 hours to cook. You’re constantly checking in, adjusting and making sure everything’s developing as it should. It takes persistence and trust that the final product will be worth it.

Arora-Cox: And what’s your go-to meal when you need to recharge?

Barnir: My partner jokes that I never cook the same thing twice. That might be where the creativity comes in—sometimes you just need to try a new approach.

Arora-Cox: Perfect. Thank you so much for your time, Amit.

Barnir: Thank you, Shellka. It’s been a pleasure.

Arora-Cox: That’s it for today. Tune in next time for more Resilience.