Stellium OCP immersion proof of concept

Project brief

What is publicly known

Status: pilot. The April 2025 announcement says Stellium Data Centres, Circle B, and Submer assembled an immersion-cooling proof of concept at Stellium's Newcastle site. The design combines Submer equipment, Circle B integration, MiTAC Open Rack version 3 servers, AMD processors, and an ExxonMobil dielectric fluid.

That bill of materials is useful because it identifies the interfaces a buyer would need to qualify. It also aligns the server format with work from the Open Compute Project, rather than presenting the tank as an isolated appliance. The source is a Submer partner release, and the linked page is no longer available at its recorded address.

The surviving record does not include a separate Stellium report, test method, capacity, commissioning date, or measured result. Cooling relevance comes from interoperability. Single-phase immersion keeps the coolant liquid while it carries heat from the servers to a heat exchanger.

The pilot can test whether server materials, cabling, fluid, tank, controls, and service procedures work together. It cannot by itself prove long-term fluid compatibility, production availability, or whole-facility energy savings. Unknowns include tank model and count, rack-equivalent density, coolant temperature, facility-water design, workload, duration, partial power usage effectiveness, fluid sampling, server warranty, and whether technicians performed live maintenance exercises.

The proof of concept should remain a pilot until the partners publish acceptance criteria and results. Repeat operation under sustained load, an operator case study, or a decision to convert the installation to production would strengthen the record. A commercial expansion with named capacity could justify deploying or operating status for that phase.

If the equipment was only assembled for a temporary demonstration and has since been removed, the current label would overstate persistence; dated operator confirmation would resolve that gap.

Status is labeled from public evidence. Supplier orders, MoUs, pilots, projects under delivery, and operating sites are not counted as equivalent.