Hainan's underwater data centre after Project Natick

Before Hainan, subsea cooling had remained at the testing stage: Microsoft submerged the first Project Natick in 2015 and ended the Orkney trial in 2020 with no commercial follow-up. The publication presents the Chinese case as the next step, with sealed modules on the seabed using seawater for heat exchange.

What is missing is the interval between outlay and first revenue. According to Data Center Dynamics, in a report of 27 November 2023, Highlander announced the first subsea test in January 2021, in Zhuhai, and deployed the 1,300-tonne commercial module in Hainan, built by COOEC, almost three years later.

This interval is idle capital. A subsea structure requires a vessel, ballast and cable before any rack generates billing, and modular expansion repeats the outlay for each unit, with cash financing the entire period without revenue.

The time between investment and first contracted revenue decides the viability of the subsea data centre.