Virginia’s major investor-owned utilities have reported how much their distribution system is being used throughout the year, offering a window into grid utilization for the first time.
Dominion Energy, which serves the booming Data Center Alley in northern Virginia, disclosed an annual utilization rate of 41% between July 2025 and 2026, indicating there’s a lot of potential headroom to serve additional loads particularly if electricity demand can be controlled or shifted, the utility said. During infrequent peak hours, however, the grid operates at an average 80% capacity, though that rate is higher or lower depending on the location.
Appalachian Power, which mostly serves the state’s rural Southwest where electricity demand is on the decline, reported annual utilization of 14%, rising to 54% during peak hours.
While it’s well-known that a lot of U.S. grid capacity goes unused for most of the year, these filings are the first to publicly quantify just how much, and propose methods for measuring utilization. The proposals are just the beginning of a potentially years-long process by utilities, state regulators, and other energy groups to finalize metrics to assess whether to build costly new infrastructure — or else make better use of existing infrastructure through technologies like battery storage, advanced transmission reconstructors, or flexible data centers.
“We’ve historically asked utilities to build for peaks. Now, we’re shifting to say, peak remains important, but there’s more we can get out of the system 8,760 hours of the year,” Ian Magruder, founder and executive director of the Utilize Coalition, told Latitude Media.
Debates over DERs, enforcement
Dominion Energy’s filing already hints at the debates to come. The utility said grid utilization metrics should mainly be used as a screening tool to identify constraints, and not be a “deciding factor” for state regulators analyzing whether to deny capital expenditures.
Deploy Action, a group that advocates for clean energy as an affordability solution and worked on the Virginia law, said in a statement that this reading is at odds with one of the legislation’s core purposes. It directs the State Corporation Commission to use utilization metrics in assessing whether non-wires alternatives are faster and cheaper to solve certain grid constraints.
Deploy Action also said Dominion and APCo “undervalued” distributed energy resources like solar and storage in its metrics, as well as flexible demand.
Dominion split its methodology into two categories: “general” and “planning” utilization. The former counts its customers’ solar and storage as assets that both consume power and add capacity to the grid, while the “planning” metric doesn’t count those assets as capacity. Dominion argued that because those assets can’t be fully relied upon when local demand peaks, they shouldn’t count as firm capacity.
Molly Knoll, senior advisor of Align Energy Advisors, isn’t concerned just yet that Dominion’s approach will undermine distributed energy resources. In an email, she said the utility provided “important visibility” into DERs on its system, which will start a conversation about how Dominion treats those resources in grid planning. Knoll added that in general, she’s cautious about drawing insights from the filings in part because they are system-wide analyses that provide limited information on localized constraints and conditions.
Dominion similarly said system-wide measurements don’t offer a holistic view of utilization or performance, and can obscure differences among specific feeders, substations, and geographic areas.
“Accordingly, the results should be considered alongside reliability, resilience, operational requirements, customer needs, and other system-specific factors,” Dominion said in its filing. Magruder agreed, adding that he hopes more granular data down to the feeder or substation level will inform a standardized set of metrics that the industry can coalesce around.
That said, finalizing standards may be years away. Dominion asked Virginia regulators to observe data trends over three to five years before approving binding metrics. Deploy Action argued that is too long, given how fast demand is growing in Data Center Alley.
“Five years is a long time to wait,” the group said. “Decisions about new poles and wires are being made today, and every year without clear metrics is another year of investments made without them.”
Grid stress for Data Center Alley
One thing Dominion’s filings made clear is just how stressed the transmission grid in northern Virginia has become.
The utility worked with the Electric Power Research Institute to develop two utilization metrics for its transmission system as well. One of those revealed how often the system is so constrained that “ordinary correction actions may not be sufficient” — events that spiked from eight in 2023 to more than 172 so far this year, spanning 2,530 hours total. Nearly all of these “Post-Contingency Local Load Relief Warnings” were concentrated in the data center corridors of Loudoun and Prince William counties.
“This does not necessarily mean that facilities are physically overloaded under normal conditions,” Dominion clarified. “Rather, it indicates that contingency margins are shrinking and operators have less flexibility available to absorb the loss of critical transmission facilities while maintaining reliable service.”
The road ahead
The debates playing out in Virginia’s docket come as part of a broader shift in how grid planners and operators value their infrastructure. The massive demand from data centers, onshoring, and electrification — combined with new hardware and software solutions — has quickly opened an opportunity to use the grid more efficiently.
Speaking onstage at Latitude Media’s inaugural Flex Summit last week, Knoll recalled how in in 2018, when she was working on time-of-use rate designs for Maryland utilities, she asked a distribution planning engineer how many more kilowatt-hours could safely flow through existing assets if peak demand was smoothed out.
“There’s just silence on the other end of the phone. The guy was like, ‘Why would you even ask that question?’” Knoll said. “The vast majority of spending was largely around upgrading aging assets. We let all that latent value sit there because we didn’t need it. And now it is rapidly being absorbed by data centers.”
For the Utilize Coalition, the goal isn’t to stop utilities from building infrastructure, but to give regulators the tools to determine when capital-intensive builds are truly necessary.
When asked what success looks like in the coming years, the panelists pointed to multiple benchmarks. Within two years, Magruder wants to see more than a dozen states enacting utilization policies, paired with federal action from the Department of Energy and Federal Energy Regulatory Commission to help scale flexible technologies. So far, California is the only other state that has passed a law similar to Virginia’s.
Knoll took a longer view, arguing it could take up to five years for utility commissions to build the institutional trust needed to align utility profits with system efficiency.
“I actually would like to see regulators trusting what the utilities are doing to the point where they can stop being helicopter parents,” Knoll said.“As long as utilities are delivering the affordability outcomes, the load interconnection outcomes, and the other things we’re asking of them, go forth and deliver power. But I think it’s going to take a little longer than two years.”
