As the global AI boom drives massive demand for computing power, data centers are consuming more electricity than ever, and much of it goes to cooling. China’s latest solution to cut this energy demand for cooling is to sink them into the sea.
Off the coast of Shanghai, engineers are preparing to sink a massive steel pod packed with servers straight into the sea. It sounds absurd at first, but it solves one of the industry’s biggest problems: cutting enormous energy bills.
Data centers run hot, and nearly 40% of their total energy consumption is dedicated to cooling. Underwater, the ocean handles that job for free. Highlander, the maritime tech firm behind the project, says these submerged facilities can save up to 90% of cooling-related energy use, which explains why China is suddenly very interested in the deep sea.
The idea isn’t entirely new. Microsoft quietly tested an underwater data center off the coast of Scotland in 2018, which worked experimentally but was never commercialized. China, however, isn’t dipping a toe. The Shanghai pod, set to be submerged in mid-October, will be one of the world’s first functional, client-serving underwater data centers.
And the eco credentials go beyond cooling. The pod is expected to run on over 95% renewable energy, drawing power from nearby offshore wind farms. It was even partially funded by government support. Highlander secured 40 million yuan (around $5.6 million) for a previous prototype in Hainan that’s still operating today.
But, of course, building a computer under the sea isn’t simple. Saltwater corrosion is an immediate threat, so the pod’s steel shell is coated in glass flake protectant. Maintenance teams won’t be scuba-diving into cables.
An elevator connects the submerged unit to a surface structure for access, eliminating the need for maintenance crews to dive down. Even so, engineers warn that laying underwater internet connections is far trickier than building on land. Some researchers have flagged another concern. These pods could, in theory, be vulnerable to sabotage via sound-wave attacks transmitted through water.
Then there’s the big ecology question. What does dumping heat into the ocean do to marine life? There’s not much data on this, but a previous Highlander test reportedly kept temperatures within a safe range. But ecologists warn that larger deployments could attract some species while driving others away. If China eventually rolls out megawatt-scale undersea farms, the thermal footprint could grow too large to ignore.
Even with the uncertainties, experts don’t see underwater data centers replacing traditional ones, at least not yet.