Lake Mariner CB-4

Niagara County, NY

Project details

Capacity 622.5 MW reported. Status planned. City Barker. County Niagara. State NY. Grid .

Overview

TeraWulf’s Lake Mariner campus occupies the former Somerset / Kintigh coal plant on Lake Ontario at Barker in Niagara County, New York, and is being rebuilt as an AI and HPC campus on about 180 of the site’s 1,800 acres. Data Center Dynamics reported that TeraWulf topped out CB-4 in March 2026, with that hall planned at 168 MW and energization targeted for the third quarter of 2026, and that six buildings are planned, three of them already live: Wulf Den at 2 MW, CB1 at 16 MW, and the first phase of CB2 at 42 MW. DCD said CB-4, CB-5 at 168 MW, the rest of CB2, and CB3 at 42 MW were slated to energize the same year, with the campus at 500 MW expandable to 750 MW. Tenants include Core42, a G42 subsidiary, and Fluidstack, which DCD said plans to lease 360 MW of critical IT load in two 10-year deals backed by Google. Data Center Knowledge described the same brownfield AI factory drawing Niagara hydropower and nuclear-heavy NYISO Zone A power, with CB-4 as a 330,000-square-foot hall using Motivair liquid cooling and Schneider Electric UPS gear. Lake Mariner Data’s project page puts full build-out at 750 MW on Western New York’s roughly 90 percent zero-carbon grid, closed-loop cooling with no lake-water draw, and 73-plus full-time jobs including former plant workers. The public map lists CB-4, CB-5, and CB-6 as three planned halls totaling 622.5 MW. Ramboll’s project note on the same brownfield conversion put CB-5 at 160 MW and tied contracted campus load to Google’s $3.2 billion backstop and a 14 percent equity stake, with Fluidstack as the AI/HPC tenant, dual 345 kV lines, and demolition of the former plant stack. Data Center Knowledge said CB-4’s fan walls are built for about 75°F room temperature and that most electricity is Niagara hydropower on a grid operators describe as roughly 90 percent zero-carbon.

The public map lists 3 map records. Reported campus capacity is 622.5 MW. All 3 buildings are planned.

Map records

Map entries are not a physical building count; campus and building scope may differ across sources.

Sources