Submer's Rubix Proposes $12 Billion, 2GW Data Center on Former Kentucky Steel Mill Site

Barcelona-based immersion cooling specialist Submer is making a major leap into the US data center market, proposing a massive facility with up to 2GW of capacity on the site of a former steel mill in Russell, Kentucky. The project, which carries a price tag of up to $12 billion, marks the company's first data center development in the United States and will be executed through its newly formed AI data center subsidiary, Rubix Data Centers.

The proposed development sits on the grounds of the former AK Steel mill, a facility that first opened in 1923 and gradually wound down operations before finally ceasing production in 2015. The site's buildings have since been demolished, clearing the way for redevelopment. According to a report from the Kentucky Lantern, Rubix has informed local officials in Russell that it plans to construct eight buildings on the property. The data center would consume an estimated 55 million gallons of water annually and is expected to create 200 full-time jobs while generating millions of dollars in tax revenue for the city.

The project represents a significant pivot for Submer, which has historically been known as a provider of liquid cooling technology rather than a developer and operator of large-scale data centers. The company launched Rubix in June 2026 as a dedicated subsidiary to pursue AI infrastructure opportunities. Rubix claims to have a powered land bank of 8GW across multiple global markets. Earlier this month, it unveiled details of its first site: a €1 billion ($1.14 billion) data center at a former chemical plant outside Barcelona.

The Kentucky proposal underscores the growing trend of repurposing industrial brownfield sites for energy-intensive AI and cloud computing facilities. However, significant hurdles remain. Rubix, which is working with Missouri-based Gateway City Consulting on its planning application, has yet to confirm how it will secure the massive power supply required for a 2GW facility. The scale of the demand will likely require coordination with regional utility providers and grid operators.

Kentucky is already becoming a notable hub for large-scale data center development. The state is home to the 401MW TeraWulf site planned in Hawesville, which is expected to be leased to AI research lab Anthropic. If approved, the Rubix project would dwarf that development in both capacity and investment, signaling a new level of ambition for the region's data center landscape.