“What’s a Gas Insulated Substation?” Dominion Didn’t Know Either

 

July 10, 2025 - During the press conference held prior to an open house for the Vint Hill Gas Insulated Substation, Elena Schlossberg, Co-Executive Director of the Coalition to Protect Prince William, recounted attending a Dominion Energy stakeholder meeting last month where they presented the proposal for a Gas Insulated Substation at Vint Hill. This is part of their piecemeal approach as they scramble to figure out how they’re going to meet power demand driven by data centers.

“What’s a Gas Insulated Substation?” Elena asked.

Dominion’s response? “I don’t know, I’ll have to get back to you.”

Why would they present a proposal to stakeholders and not have a representative there who knows the answers to basic questions like that?

In a quick turnaround, we went from “I don’t know, we’ll get back to you,” to Dominion Energy hosting an open house to share information with the public... maybe we’ll get more answers then.

Excerpt from GreenRisks Blog from Elizabeth Ward:

Dominion Energy is planning an upgrade to the Vint Hill Substation in Nokesville, Virginia, to meet the growing energy demands of data centers in Prince William and Loudoun Counties and maintain compliance with federal reliability standards. The project will involve adding 500 kV equipment, including transformers and Gas Insulated Substation (GIS) technology, as well as new 230 kV infrastructure. The substation's footprint will be expanded on Dominion Energy-owned property in Nokesville, but no new permanent electrical easements are needed. Construction is expected to begin in Spring 2026.

Gas insulated substations use sulfur hexafluoride (SF6) which is the most potent greenhouse gas known to mankind. Over a 100-year period, SF6 is 23,500 times more effective at trapping infrared radiation than an equivalent amount of carbon dioxide (CO2). SF6 is also a very stable chemical, with an atmospheric lifetime of greater than 1,000 years. As the gas is emitted through leak or accidental release, it accumulates in the atmosphere in an essentially undegraded state for many centuries. Thus, a relatively small amount of SF6 can have a significant impact on global climate change. >>read full blog here

Prior to the open house, PWCA participated in the press conference organized by the Coalition to Protect Prince William to highlight this issue further. Below are comments from our Chair, Jean Beard, reminding us that this is yet another example of the piecemeal approach Dominion is offering us.

This isn’t smart growth or comprehensive planning. It’s death by 10,000 cuts. Prince William County residents and wildlife deserve better!

Good evening, everyone. I’m Jean Beard, Chair of the Board of Directors at the Prince William Conservation Alliance. I’m honored to be here tonight representing a nonprofit deeply committed to protecting Prince William County’s natural resources, our communities, and the future we’re all working to build together.”

Let’s be clear: Dominion Energy’s proposal for a new Gas-Insulated Substation is yet another consequence of unchecked data center expansion in Prince William County. This isn’t just about one substation — it’s about the cumulative impacts of a data center gold rush that is transforming our communities with little forethought or transparency.

For years, Prince William Conservation Alliance has been a leading voice calling for responsible, comprehensive planning. We’ve urged the County to take a smarter, more holistic approach to data center development — one that prioritizes appropriate siting, thorough environmental studies, and meaningful community input before approvals are granted.

Yet instead of measured planning, we’ve seen a frenzy. The Data Center Opportunity Overlay District was never comprehensively reviewed. The Occoquan Reservoir model — critical to understanding the risks to our drinking water — remains incomplete. And in the meantime, Prince William County is poised to outpace Loudoun as the global capital of data centers. Just four years ago, most residents hadn’t even heard of a data center. Today, our parks, our waterways, our neighborhoods, and even our schools are feeling the pressure of this industrial-scale development.

Four years ago, we rallied against a single proposal to build a data center near the headwaters of Quantico Creek — one of our highest-quality streams — inside the legislative boundary of Prince William Forest Park. Today, residents are tracking dozens of proposals in their spare time because the county, dominion, or any other authority, surprisingly, aren’t. With over 88 million square feet of data centers approved — and more on the way — we’re not just concerned about the buildings themselves. We’re deeply alarmed by the sprawling infrastructure they require like substations and transmission lines and we’re alarmed about more gas plants, diesel generator back up, nuclear reactors, and more gas pipelines to meet this load demand.

At PWCA, we’re not anti-technology. We’re pro-planning. We’ve long called for cumulative impact studies, full transparency, and accountability for the ways these projects affect our environment, our health, and our wallets.

Tonight’s meeting is yet another example of the domino effect caused by runaway data center growth. This substation may be framed as “routine” or “necessary” — but make no mistake: it’s being driven by the energy demands of massive, energy-intensive data centers. And Dominion is scrambling to keep up. Localities have approved far more data center development than our current electrical grid can support — pushing the state’s energy demand from 23 to a projected 40 gigawatts.

This rush threatens to derail Virginia’s clean energy goals, increase pollution, and impose new burdens on local communities. And yet, what we’re seeing isn’t coordinated infrastructure planning — it’s a piecemeal approach. A transmission line here. A power plant there. No clear roadmap. No honest accounting of costs. No comprehensive plan to show the public where all this infrastructure is going, or who will be left holding the bill.

This isn’t just poor planning — it’s planned disregard. This isn’t growth — it’s a thousand tiny acts of destruction. It’s a land grab disguised as a power upgrade — and Prince William County is the target. Prince William County deserves better. Full stop.”

>>Watch the full press conference