In a move that suggests the future of sustainable data center design, China has built and is now continuing to expand on the world’s most advanced underwater data center. The massive facility, submerged 25 meters underwater off south China’s Hainan province, has enough compute power to process over 4 million high-definition images in 30 seconds, equivalent to 60,000 traditional computers.
Compared with land-based data centers, the benefits of the Hainan facility’s next-gen underwater infrastructure are numerous. It has lower cooling costs due to its use of cold seawater, and it minimizes land usage—data centers can devour a lot of real estate. The submerged facility’s isolated location enables enhanced data security, and also offers lower carbon emissions by using renewable power sources like tidal power and wind-based energy.
The subsea data center is operated by Highlander, a Chinese company that has been developing underwater data center capabilities since 2020. It conducted tests in the Chinese port of Zhuhai in 2021, and after additional testing, the company launched its first submerged facility off the Hainan province in 2023. The facility is unmanned, and consists entirely of servers and network gear with no need for human hands-on maintenance. If a subsea facility needs an overhaul, it can be brought up from its undersea location.
Inspired by the Hainan facility, a number of Chinese regions have included plans for an underwater data facility into their five-year plans.
The 1433-ton Hainan facility, which uses a modular design, has seen continued development. Recently, an 18-meter craft was used to submerge an additional module to interoperate with the existing facility. Highlander has not detailed the exact specs of the data center’s hardware, but the China News Service indicates the new addition contains 400 high-speed servers and offers remote computing power to customers via an onshore location.
Some 10 companies have contracted to leverage the data center’s compute power and other tools for industrial applications, scientific research—particularly for marine research—game development and AI training and inference.
Highlander was reportedly inspired by Microsoft’s efforts at an underwater facility. In 2018, the software giant launched Project Natick, a data center submerged off the coast of Scotland and containing 855 servers. Microsoft operated the servers—without any human hands-on support—for a little over two years. Six of the servers crashed during the period, which compared with Microsoft’s tally of eight servers crashing on dry land. The company concluded that the cooling temperatures of seawater created this improved performance.
Also supporting improved performance: Microsoft’s underwater facility was filled with inert nitrogen gas, in contrast to the reactive oxygen gas used in traditional data centers. (The oxygen gas systems, which are breathable by humans, help prevent fire by reducing oxygen levels.)
Microsoft later abandoned the project, but notes that it was a valuable learning experience the company will continue to use in future data center designs.
The subsea data center sector has attracted a budding cohort of vendors, including NetworkOcean, which touts the far lower failure rate of submerged hardware compared with land-based facilities; and Subsea Cloud, which offers customers a 90-day trial before making any additional commitments. Subsea claims that its submerged data centers offer a 40% reduction in carbon emissions and a 30% reduction in operational costs.
