Loudoun County reports the world’s highest concentration of data centers; Dominion says the cluster requires major transmission and generation investment to meet growing electricity demand.
By Deep Field
You have almost certainly never heard of Loudoun County, Virginia. It sits roughly forty kilometres west of Washington DC, covers about 520 square miles, and holds about 450,000 residents, which is fewer people than live in the Newcastle-Gateshead metropolitan area in the north of England. The place is not on any tourist itinerary, and it isn’t famous for anything the way a wine region or a beach town is famous. Yet there is a reasonable chance that when you last opened Instagram, checked your bank balance, or asked an AI assistant anything at all, the packet of data doing the work touched a warehouse full of servers in Loudoun before it came back to your phone.
A widely repeated claim says that around 70 percent of the world’s internet traffic passes through Loudoun. The county’s 2021 revenue and tax policy study described that figure as frequently quoted but did not establish its accuracy. What is not disputed is that Loudoun has the highest concentration of data centers anywhere in the world, and that Ashburn, its small unincorporated community at the eastern end, is a major hub of the physical internet.
How it got there
The story begins in 1992, when engineers from Metropolitan Fiber Systems and UUNet ran a set of cables together in a parking garage in nearby Vienna, Virginia, creating one of the first commercial internet exchange points on Earth. That exchange, known as MAE East, was the physical location at which competing internet service providers agreed to pass one another’s traffic to each other. It made the neighboring flat land in Loudoun the most attractive real estate in the world for anyone who wanted their servers to reach the rest of the internet in as few milliseconds as possible. When America Online opened its headquarters in Ashburn in 1996, and UUNet followed two years later, the pattern was set.
In 2000, the county’s zoning administrator decided, for administrative simplicity, that data centers should be regulated like ordinary office buildings, which meant that developers could build them by right in vast swathes of the county without any additional legislative approval. According to the Loudoun County government’s own official history of the industry, that single administrative determination, made in a suburban zoning office, produced the largest data center cluster on Earth over the following twenty-five years.
If you want the bigger picture behind that queue, the video below has it — the pledges made before the AI boom, what’s actually happened to the emissions since, and why the companies most committed to fixing this are the ones driving the demand.
The current scale
As of 1 March 2026, Loudoun County reported approximately 233 data-center buildings, built or under construction, representing roughly 56.5 million square feet of gross floor area. The county says recent permits issued since 2023 show that the average new building is closer to 339,000 square feet. A further 35.7 million square feet is approved but not yet built, and another 20.7 million square feet is in the legislative pipeline waiting for approval. Data center-related tax revenue reached $1.2 billion in fiscal year 2026, which is 39 percent of the entire county budget. The projection for 2027 is $1.3 billion, at 40 percent. In a jurisdiction that used to depend on residential property taxes, roughly two out of every five dollars the county spends now come from server warehouses.
The utility problem
The utility that serves this cluster is Dominion Energy Virginia, and its 2025 annual report to the Securities and Exchange Commission makes for genuinely startling reading. According to Dominion’s own SEC-filed 2025 annual report, data centers already accounted for 28 percent of the total electricity Dominion Energy Virginia sold in 2025, up from 26 percent the year before. Peak load in the region is projected to grow by 5.4 percent per year over the next decade, and 38 of the top 50 all-time peak demand records for the region were set in 2025 alone, with the 22 highest all belonging to that single calendar year. The company is carrying more than 48 gigawatts of additional data center capacity in various stages of contracting, a figure roughly equal to the entire electricity consumption of the United Kingdom on a summer afternoon.
The queue for new connections is now measured in years. Independent industry reporting has documented cases where delivery timelines for facilities above 100 megawatts have stretched from three or four years to as long as seventeen, and in response some data center operators have begun building their own onsite gas turbines and running diesel backup generators for days at a stretch when the grid falters.
The response
The pushback has arrived on multiple fronts. In 2025, Loudoun County eliminated the by-right development pathway for data centers, requiring future proposals to go through a special exception process with a public hearing and a Board of Supervisors vote. Dominion, at the state utility commission’s direction, will begin requiring high-load customers from January 2027 to sign fourteen-year commitments to pay for the power they have asked for even if they use less, as a way of stopping speculative applications from clogging the queue. Multiple bills before the Virginia General Assembly have attempted to give local governments legal authority to deny data center applications where the grid cannot support them.
What this actually is
The internet has always been physical: the cloud is a warehouse, and the AI everyone is talking about is a rack of processors that draws as much power as a small town. What is different about Loudoun is not that the physical layer exists there but that so much of it exists in one place, having outgrown the electrical infrastructure of the actual county it sits in, being asked to accommodate an artificial intelligence boom that, on current forecasts, will double its power demand again by 2030. The queue for new connections is measured in years because the grid it was built to serve was designed for something else entirely.