How a Coal Plant in Buffalo Became TeraWulf’s 500 MW AI Campus

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How a Coal Plant in Buffalo Became TeraWulf’s 500 MW AI Campus Data Center Knowledge toured the TeraWulf and Schneider Electric campus in Buffalo, N.Y., to see what it takes to power – and cool – the data centers of the future. BUFFALO, N.Y. – On the grounds of a retired coal plant outside Buffalo, TeraWulf is confronting one of the AI era’s defining challenges: how to cool increasingly dense compute as rack power soars. Across roughly 180 of the site’s 1,800 acres, the company is building an “AI factory” – a campus optimized for accelerated compute with liquid cooling and modularized power – powered by Nvidia chips, Schneider Electric hardware, and Motivair cooling systems. The campus, called Lake Mariner, currently delivers 500 MW across four data halls, with plans to scale to 750 MW. Tenants include Core42 and Fluidstack, the latter of which hosts compute tied to Google AI workloads. “Rack density is increasing, and that changes everything,” Manish Kumar, executive vice president of Secure Power and Data Centers at Schneider Electric, told Data Center Knowledge. “At the same time, data centers themselves are getting bigger. We used to talk about 50 MW or 100 MW facilities – now we are seeing projects at the 500 MW-plus scale. As facilities grow, so do their requirements: power, thermal, and digital.” Rows of server racks line a high‑density data hall at the Buffalo campus. (Image: TeraWulf) Liquid Cooling at Hyperscale: Closed-Loop Systems, RDHx, and Fan Walls To manage rising density, Schneider Electric and Motivair (which Schneider acquired a controlling interest in in February 2025) have deployed more than $290 million in AI infrastructure and liquid-cooling systems at the site. Rather than traditional evaporative cooling – long scrutinized for high water use – the campus relies primarily on a closed-loop system that minimizes consumption. Cooling water circulates through sealed infrastructure with glycol mixtures and corrosion inhibitors, which operators say provide a system lifespan of 10 to 15 years. Rows of rear-door heat exchangers (RDHx) capture heat directly at the rack and circulate it for cooling; 144 units are installed in one section of the campus alone. In CB4, the fourth hall under construction and expected to be energized by July 2026, fan walls are being built to maintain room temperatures around 75°F (25°C). Outdoor spray cooling systems come online only during peak loads and high heat – generally when outdoor conditions exceed about 85°F (25°C), which operators say occurs less than 5% of the year. Rows of rear‑door heat exchangers capture heat at the rack, routing it into the campus’s closed‑loop cooling circuit. (Image: TeraWulf) The site still benefits from legacy water infrastructure dating back to its coal plant days, including an intake connected to Lake Ontario with a capacity of approximately 275 million gallons. Even so, executives say the newer liquid-cooling systems are more efficient and environmentally preferable – if more expensive – than conventional methods. “We really want to draw attention to the fact that liquid cooling does not equate to water consumption,” said Tuan Hoang, head of cooling technology at Schneider Electric. “If we relied on older systems for compute demands, we would need dramatically more infrastructure to deliver the same performance.” Overhead coolant hoses, power distribution, and cable trays feed the server rows below. (Image: TeraWulf) Powering 500-700 MW: UPS Architecture, Grid Mix, and Niagara Hydropower Energy availability is the other major constraint. “The biggest bottleneck is access to utility power,” said Steven Carlini, chief advocate of data centers and AI at Schneider Electric. “Data centers are now being built wherever operators can secure electricity, whether that’s from the grid, natural gas turbines, or renewable energy developments.” He added: “We’ve gone from a situation where operators built data centers and hoped customers would come, to one where demand is so intense that everyone is scrambling for access to power, connectivity, and water.” A front‑of‑rack view shows active server rows in a high‑density aisle at the Buffalo campus. (Image: TeraWulf) The campus draws power through 450 UPS systems ranging from 1 MW to 1.5 MW, along with modular electrical infrastructure delivered in prefabricated units. Most electricity is sourced from New York's hydro- and nuclear-heavy grid, with reliance on Niagara hydropower, which operators describe as approximately 90% zero-carbon and relatively inexpensive. According to Carlini, utilities are prioritizing projects that are more sustainable, use less water, produce lower carbon emissions, and are backed by experienced developers – further incentive for operators to pursue more sustainable processes. Exterior utilities serving the campus, featuring elevated control panels and maintenance access. (Image: TeraWulf) Looking ahead, Carlini anticipates concerns over power consumption will ease as alternatives are integrated into operations. "We have the technological ability to solve these problems," he said. "AI will absolutely require much more power, but I think some of the concern is overstated. There are already multiple ways to address it, whether through energy storage and peaker plants, or small modular reactors coming online." He views the current moment as the beginning of a longer refinement process that will yield AI factories built for specific, optimized workloads. "We're still at a very early stage," he said. "There’s a lot of change and excitement ahead.”