Although data centers have been part of the national conversation for years, they have only become a hot topic in Seattle over the past few months.
On May 11, the Seattle City Council held a special Land Use Committee meeting to discuss proposals to limit the construction of new data centers in the city. At the meeting, Councilmember Alexis Mercedes Rinck asked Council Central Staff how many data centers are in Seattle. No one could give a definitive answer.
Even so, the council held significant votes on data centers over the next few months. They passed two bills on June 9 that specifically target the construction of new data centers and establish a strict policy framework for future data center proposals. Then, on July 7, the council passed the new Seattle City Light Strategic Plan, which includes a new power rate for both new and existing large data centers.
While the council moved relatively quickly in passing the legislation, becoming the first major city in the country to pass a data center moratorium, it appears that most of the data center build-out has already happened in the Seattle metro area.
According to the website Data Center Map, there are at least a dozen data centers in Seattle, mainly downtown. But the site's map also shows 18 data centers in one industrial park in Tukwila, 17 of which publicly report their power capacity. Collectively, those data centers reported that they could draw 80 to 113 megawatts at maximum capacity. If these data centers sustained that demand for a month, they would consume about 57,600 to 81,360 megawatt-hours of electricity — equivalent to the monthly electricity use of 94,000 to 133,000 Seattle-area homes.
Although the council votes received extensive news coverage, the legislation does not substantially affect the industrial park's 18 data centers in Tukwila. The moratorium and framework legislation apply only to data centers in Seattle, while the new power rate for large data centers would affect no more than five data centers in Tukwila.
All of which leads to a number of questions: Where are the data centers that fall outside of Seattle's purview? And what goes on inside them?
After the Emerald reached out to several data center companies to see what happens inside and assess the scale of the industrial park, one company, DataBank, agreed to a tour.
The Emerald took the #124 bus to Tukwila International Boulevard and South 130th Street, then walked through a nearby residential and commercial neighborhood to the industrial park.
Across the street from King County Metro's Tukwila Base, the industrial park looked benign. A small metal sign outside listed some of the data centers in the park, but there was no audible electrical hum or other signage to indicate that more than a dozen facilities were nearby.
The majority of the data centers in the park are "colocation data centers," where clients bring their own servers, while the data center provides the space and infrastructure to power, cool, and secure them. Only one company, IBM, owns and operates a data center in the park for its own business needs.
After an ID check and a signature on several documents, DataBank representatives led the Emerald on a tightly controlled tour. The tour went through different rooms that contained greenhouse-like structures, called data halls, which housed black vertical shelving units called racks. Each rack has up to 30 shelves, with each shelf holding an individual server, a computer that stores and delivers electronic information.
In the one data hall that the Emerald was allowed to tour, there were nearly 1,000 servers. Entry wasn't allowed in other spaces at the data center.
The tour guides explained that water is piped down from the ceiling, chilled, and brought below the floor, which has thousands of tiny holes. Cold air is then released in the greenhouse structures, cooling the servers, while the hot air is released outside the greenhouse. The water is then piped out of the room, and the cycle repeats.
The DataBank data center is a "closed-loop" system, meaning the water used today to cool the servers is the same water it used when it opened in 2000, and no additional water has been added for cooling. The only new water that comes into the data center is used for on-site fixtures like sinks and toilets. A DataBank representative claimed that this data center uses 50% less water per year than an average family of four.
The 45-minute tour ended outside the data center, in a walled-in space that was open to the sky. The space contained the data center's four generators and water-pumping station, which were loud enough to make normal conversations difficult. But exiting the space, on the other side of the walls, the noise was minimal.
Throughout the tour, DataBank representatives repeatedly responded to public concerns by saying the Tukwila facility uses less water per year than an average family of four, data centers are essential to modern society, and utility companies benefit from having data centers as customers.
One major criticism aimed at data centers is their heavy use of water to cool their servers, especially AI data centers.
DataBank representatives said the facility uses about 50,000 gallons of water per year. They also said that the statistics cited by critics of data centers are "misleading," because they focus on more water-intensive data centers, such as AI and evaporative-cooling data centers, rather than closed-loop ones.
In an email, Burkhard Englert, Ph.D., department chair of computer science at Seattle University, wrote that if the DataBank data center were as water-efficient as it claims, it would be "consistent with a well-built closed-loop system doing exactly what it's designed to do." And, Englert added, while there is a "kernel of truth" that critics sometimes lump together the water usage of all types of data centers, it's not a "full defense" of data centers.
"The operator is right that not all data centers are equivalent, but if the implication is that the industry's real water footprint is basically closed-loop and a non-issue, that's likely an overstatement. I'd treat their framing as legitimately informative but self-interested, true within limits, and offered because it makes them look good," he said.
Representatives from DataBank said that data centers are needed for everything that happens on the internet, such as banking, cloud storage, and streaming, and that without them, we would be "living in the 1980s." The representatives also claimed that people are angrier about AI and that if people are concerned about water and energy use, they should "ban AI, not data centers."
Englert agreed that data centers are "the physical backbone of the modern economy and of most public services at this point," but said the point about AI was "deflection."
"The industry framing, 'Don't worry about data centers generally, worry about AI,' is used strategically to shift scrutiny away from the broader footprint of the build-out and onto a narrower slice of it," said Englert. "It's not wrong that AI facilities use more resources, but it can function as deflection when it's used to wave off concerns about data center growth overall."
As for DataBank's claim that utility companies like data centers for grid maintenance and stabilization, along with power maintenance and efficiency, a representative with Seattle City Light did not agree.
"City Light does not expect any type of new large loads to provide benefits to the existing grid," said Julie Moore, communications director for Seattle City Light. "In fact, the cost of serving any new large load is expected to be significantly higher than the cost of serving existing retail customers."
But how does City Light feel about existing data centers, like the ones in Tukwila? Moore would only say, "Existing data centers throughout our service area were added over time, tend to be small, and have been integrated into our system for many years. We are in a different place today."
Englert said that both DataBank and City Light had valid points. Data centers are "large, predictable, and steady" customers for electricity companies, he said.
"That's attractive to a utility," said Englert. But "large new data centers can also strain the grid, requiring new generation, transmission, and substation investment, sometimes years ahead of when that capacity is needed for anything else."
Currently, there is no legislation in Tukwila concerning data centers, and Seattle has less than a year to formalize its plans. Meanwhile, in one Tukwila industrial park, 18 data centers continue to operate in largely unmarked buildings close to a residential neighborhood.
We're building a newsroom rooted in community, not corporate backing. Help us raise funds to hire our first-ever full-time reporter and grow our capacity to cover the South End. Donate today.