Branford ― Cloudsmart data center President Robyn Sullivan walked down one of the nondescript office building’s barren, off-white hallways on a late August afternoon, stopping at a door with a sign that warned against unauthorized entry.

She pushed the door open, but did not step inside.

Beyond her, lights flashed from racks and racks of servers. Wires ran under sections of raised flooring, eventually poking up and feeding into them. Air conditioning hummed to combat the heat generated by the servers.

Branford residents and town officials say they’ve had no complaints about the data center, which was built in 2010.

Perry Maresca, economic development and business director for the town, said hosting the data center at 4 Pin Oak Drive, inside an industrial park, has been beneficial to the town’s economic development, drawing in other tech companies that use its services and generating tax revenue.

“Certainly it’s been a positive for Branford,” Maresca said.

But can this type of data center be compared with NE Edge’s proposal to build a 1.2 million square-foot data center on the site of the Dominion Energy Nuclear Connecticut Millstone Power Station in Waterford?

In an attempt to draw comparisons to the Waterford project, we looked at other data centers in the state to see how they compared with the NE Edge proposal in terms of size, use, how they’re powered and cooled and whether or not residents living near them had any concerns.

In addition to Branford, data centers have existed for years in Windsor, Trumbull, Stamford, Hartford, Norwalk and Waterbury.

In early 2023, NE Edge, led by President Thomas Quinn, began talking with Waterford about constructing two data center buildings and a switchyard at the Millstone site. The buildings would house thousands of graphics processing units (GPUs) that would be used to train and operate artificial intelligence.

The discussions led to a unanimous decision by the Representative Town Meeting and First Selectman Rob Brule to enter into a host fee agreement with the company. The agreement set a payment to the town of $231 million in lieu of taxes over 30 years, and set forth guidelines on sound and environmental impact.

Concerned residents of East Lyme and Waterford, who formed a group last summer to oppose the project, have criticized what they say would be the data center’s impact on the environment, on electric ratepayers and the quality of life of residents in nearby neighborhoods. One of their chief concerns is the noise they believe the project would create.

Quinn has said the project would be powered by 300 megawatts of electricity from Millstone’s two operating nuclear reactors, which is approximately 15% of the plant’s output.

None of the state’s existing data centers compare to the NE Edge project due to its much larger size, which Quinn and industry experts have said is necessary due to its intended use for artificial intelligence.

NE Edge data center would be a first of its kind in the state

Data centers have existed in Connecticut at least since the 1980s, long before Gov. Ned Lamont signed a 2021 law that promised significant tax incentives for companies that develop data centers in Connecticut. Only one has successfully taken advantage of the new tax incentives ― a 153,462-square-foot Cigna data center in Windsor.

Windsor will not receive any payment in lieu of taxes but instead will benefit from an increase in taxable property as a result of the upgrades, according to a host fee agreement for the project.

Cigna officials did not respond to numerous attempts to discuss the project. Media reports on the project have not indicated if it is being used for artificial intelligence.

The Cigna building was built in 1982 and in 2022, the company announced it would spend $386 million to upgrade the facility and signed a host fee agreement with the town.

Assistant Town Manager Scott Colby said the Cigna project is “nothing in size comparison with what they’re looking at down in Waterford,” adding residents have not spoken out for or against the project.

“It’s not near any residential area, so it hasn’t had an impact on anybody over there,” he added. “I think a lot of people don’t know what it is. Plus, it’s very small.”

Data centers smaller than the NE Edge project are more common in the state, including the 16,000-square-foot Cloudsmart. Sullivan said the company and other existing data centers provide space to house customers’ servers.

But in recent years, data center demand both here and nationwide has been driven by a different technology ― the increasing appetite for artificial intelligence, which requires immense amounts of data. That has pushed the need for a new type of data center, ones that need bigger buildings filled with hundreds more servers, and require more power and cooling.

These kinds of data centers have been dubbed “hyperscale,” a term that reflects their supersized approach to data storage. There’s no industry-standard guidelines for what qualifies a data center as hyperscale.

Industry experts just say they’re big, and that many such as the one proposed by NE Edge are now being built throughout the United States.

A traditional data center

Robyn Sullivan, president of Branford’s Cloudsmart since 2016, said the data center was built in 2010 by a different company, RECOL.

Sullivan’s company took it over in 2016. The data center is located within an industrial park less than 1,000 feet from Interstate 95, where Sullivan said it shares a building with four other businesses.

Sullivan pointed out the distinction between traditional data centers like hers and “hyperscale” ones, during last week’s tour.

In a fenced area behind the Cloudsmart building, Sullivan pointed to approximately 10 compressor units, used to create cold air to cool the servers inside the building, which get very hot.

The fans were spinning noisily, though it was possible to hold a conversation within a few feet of them. Soon after leaving the parking lot, they were barely audible, drowned out by the noise of the nearby highway.

“A hyperscale data center, in my mind, has hundreds (of fans). It’s like, everything’s done at such a larger, higher degree, is my understanding,” Sullivan said.

She noted the hyperscale data centers have taken over towns like Reston, Va., which she called “one of the data center capitals of the United States.”

Reston, along with the neighboring city of Ashburn, is located in a geographic zone of Northern Virginia commonly referred to as “data center alley.”

“That place is filled with hyperscale data centers and it’s kind of like, the hum of the town,” said Sullivan, who has been in Reston. “Like you hear, kind of, the compressors going. There’s tons of them in that area.”

“So that’s where you get the sound problems ― as it scales up. You keep scaling and scaling and scaling,” she said.

Many of the data centers in Northern Virginia cool their hardware with water. The Financial Times obtained data indicating that data centers operated by tech giants like Amazon, Google, and Microsoft used more than 1.85 billion gallons of water in 2023 ― up from 1.13 in 2019.

Quinn in May said the NE Edge project would utilize outside compressor units paired with rooftop fans.

In making the argument that the facility would be quiet, he said the rooftop fans would be covered, and a 15-foot, insulated parapet wall would be installed around the compressor units.

Quinn said NE Edge’s project would not use diesel generators, which commonly contribute to the noise level, and would instead receive its backup energy from the grid, making it quieter.

At Cloudsmart, a 500kW diesel generator would power the facility in the event of a grid outage.

Privacy and security

Inside the Cloudsmart facility, the noise of the machinery created a rushing kind of sound, as loud as a bus going by.

“That is a combination of obviously, servers running, but also all of the equipment,” Sullivan explained.

She held a door open but did not allow admission into a room that demonstrated the data center’s most popular service ― to provide a secure space for its customers’ servers.

Sullivan added that Cloudsmart provides the power, cooling, circuits, internet, and backup power “so that even if the customer were to lose power, they wouldn’t lose the data, because we’re always running.”

Sullivan closed the door, and the noise was almost fully reduced to a dull drone, about as loud as a household air conditioning unit.

“A data center -― one of the number one things is privacy and security,” Sullivan said. “So, we make sure that nobody that isn’t a customer enters that space ― it protects customer data.”

“You don’t want somebody going in and grabbing someone’s server,” she explained. “Or even grabbing, maybe, a USB out of one of their servers and being able to take information.”

She showed an adjacent room, where there are three racks of Cloudsmart’s own servers. The room and Cloudsmart staff provide customers with two other valuable services.

The first is disaster recovery services.

“It’s backing up a company’s data, keeping it safe, and being able to ― if by some chance they were hit by ransomware or some other catastrophic event ― that we could spin up their data right back to them from the cloud,” Sullivan said.

The second is hosting of websites and emails.

Providing server space and backing up data to the cloud is not a new technology, Sullivan said. Thus, data centers have existed to provide these services for decades.

Residents unaware of Branford data center

A small sampling of Branford residents and town officials show no concerns with the small data center.

Three residents living in the closest neighborhood, about a half-mile from the data center, said they didn’t even know it existed.

Michael Scott, an architect, lives at the end of Towner Swamp Road in Guilford, with thick woods between his home and the data center.

“My wife and I were not aware of it,” Scott said.

The decibel reading on an IPhone app near his house in the early afternoon was about 47 decibels ― quieter than a household refrigerator. There was no apparent hum from the data center, but the nearby highway could be heard.

“I would suspect that the only thing we hear is 95,” he said.

Branford First Selectman James Cosgrove said he hasn’t heard any residents’ concerns about Cloudsmart. He added that Branford is a small town looking to maximize its development assets, and since being built, one benefit of the center is that it has drawn attention from tech companies who have moved nearby to utilize its services.

“We have a lot of biotech and life science companies, lot of research and labs, and they do rely on a lot of the data to be safely maintained,” Maresca said. “So that is part of what they look for when they come into town.”

Maresca said that would be something for residents to consider in weighing the benefits of the NE Edge project ― that it would presumably bring more tech business into town, which would result in additional tax revenue.

“I would think it would be something that would be positive for businesses that are there, or that are looking to come into the area,” he added.

Norwalk, Stamford, Hartford, Waterbury data centers

Companies that operate data centers in Norwalk, Stamford, Hartford and Waterbury could not be reached to answer questions about their centers.

According to the website for CyrusOne, a data center developer and operator based in Dallas, Texas, the company operates data centers in Norwalk and Stamford. They provide similar services to the Cloudsmart data center, space for servers for backup and business continuity services.

The Norwalk data center, called NYM5, is a 150,000 square-foot facility located less than 300 feet from I-95. It features 75,000 square feet of space to house servers . The amount of power it uses is not listed on its website.

Norwalk Planning and Zoning Director Steve Kleppin said he doesn’t know the exact year the facility was built, only that it was approved in 2012.

“I have never heard of any issues with that facility in my eight years here,” he said.

The Stamford data center, called NYM10, takes up 57,000 square feet and features 20,000 square feet of server space. The amount of power it uses is not listed in the specifications.

Stamford officials declined to discuss the project.

A Tierpoint data center in Waterbury occupies part of a five-story office building at 108 Bank St., said City Planner Robert Nerney. The building, built in 1883, has a total area of 35,950 square feet. He said the company has applied for a few electrical permits for the site, including to install a 400 kW generator on the roof. Nerney couldn’t say how much of the building was being used for the data center.

He said there wasn’t a lot of public focus on the use of the building during the permitting process.

“And certainly not the public scrutiny that a 1.2 million-square-foot building would receive in the community,” he said.

d.drainville@theday.com