China Opens World's First Wind-Powered Underwater Data Center

Overview

China has put the world's first offshore wind-powered underwater data center into full operation off the coast of Shanghai's Lingang Special Area. Built by Shanghai Hailanyun Technology, known as HiCloud, the submerged site runs at a capacity of 24 megawatts, houses close to 2,000 servers, and draws about 95 percent of its electricity from a nearby offshore wind farm. Surrounding seawater cools the racks passively, removing most of the power that land-based centers spend on air conditioning.

Key Takeaways

The data center sits about 10 meters below the surface, more than six miles offshore, ringed by a farm of over 50 wind turbines that supply roughly 95 percent of its power.
It holds close to 2,000 servers across 192 racks inside sealed, pressure-resistant subsea modules, and runs AI training, big data, and 5G network tasks.
Seawater circulating through the racks acts as a natural heat sink, which operators say cuts electricity use by about 22.8 percent versus land-based sites.
The facility reports a power usage effectiveness below 1.15, well under the industry average near 1.5, meaning it wastes far less energy on cooling.
Partners have already signed an agreement for a 500-megawatt underwater cluster, more than 20 times the size of the current site.
The design eliminates freshwater use for cooling and reduces land use by more than 90 percent compared with conventional facilities.

Stats & Key Facts

#24 megawatts: full operating capacity, housing close to 2,000 servers
#About $226 million: reported construction cost of the facility
#Below 1.15: power usage effectiveness, against an industry average near 1.5
#About 95 percent: share of electricity drawn from the adjacent offshore wind farm
#22.8 percent: reported reduction in electricity use versus land-based data centers
#500 megawatts: planned capacity of a follow-on underwater cluster, over 20 times larger

Submerged Off Shanghai's Lingang Coast, Ringed by 50-Plus Wind Turbines

The site location pairs deep water with strong, steady offshore wind.

›Positioned off Shanghai's Lingang Special Area, about 10 meters below the surface and more than six miles from shore.
›Surrounded by a farm of more than 50 offshore wind turbines that feed the bulk of its power directly.
›Built by Shanghai Hailanyun Technology, known as HiCloud, working with China Communications Construction and other state-linked firms.
›Full commercial operation began in 2026 after an earlier demonstration phase ran at 2.3 megawatts in May 2026.

How Seawater Cooling Replaces Energy-Hungry Air Conditioning

The ocean itself does the work that chillers do on land.

Land-based data centers spend a large share of their power running air conditioning and chillers to keep servers from overheating. Some sites use up to 40 percent of their energy on cooling alone. This facility avoids most of that cost by sitting in cold, stable seawater.

The design circulates surrounding seawater through radiator-equipped racks, using the water as a natural heat sink. Heat from the servers rises by buoyancy to an upper cooling layer, where a heat exchanger transfers it into the seawater. Operators report this cuts electricity use by about 22.8 percent compared with conventional land sites.

Near-1.15 Efficiency Rating and a $226 Million Build Cost

Efficiency numbers put the site among the cleanest large computing facilities running today.

›Reported power usage effectiveness below 1.15, against a typical industry figure near 1.5; lower numbers mean less wasted energy.
›Construction cost reported at about $226 million.
›About 95 percent of electricity comes from the adjacent wind farm, making it one of the lowest-carbon computing sites in operation.
›The approach eliminates freshwater use for cooling and reduces land footprint by more than 90 percent.

Inside the Subsea Modules: 192 Racks Running AI, Big Data, and 5G

The hardware is packed into sealed pressure-resistant pods.

›Holds close to 2,000 servers across 192 racks arranged over four levels inside sealed subsea modules.
›Includes GPU clusters supplied by Chinese telecom and computing companies for AI work.
›Workloads span AI model training, big data annotation, domestic large language model development, and 5G network support.
›Named clients include China Telecom and LinkWise.

How It Compares to Microsoft's Project Natick

China is not the first to test undersea servers, but it is the first to run a wind-powered grid-connected one at this scale.

Microsoft ran an earlier underwater experiment, Project Natick, off Scotland starting in 2018. That trial operated 855 servers for more than two years and recorded only 6 failures, against 8 failures among 135 comparable servers on land. The sealed, oxygen-free, temperature-stable environment appeared to improve reliability.

The Shanghai project pushes the idea from experiment toward commercial scale, tying servers directly to offshore wind and running live AI and network traffic. HiCloud also operated an earlier underwater site near Hainan in 2023, giving it operating history before this larger build.

Environmental Questions: Waste Heat and Marine Life

Dumping server heat into the ocean raises ecological questions worth watching.

Cooling with seawater means waste heat goes into surrounding waters. Studies of thermal discharge show it can change oxygen and pH levels and sediment composition, which sometimes lowers local marine biodiversity. Critics point to this as the main open concern with scaling the design.

HiCloud reports that water temperature around its 2023 Hainan facility rose less than 1 degree Celsius, and that fish gathered around the modules for shelter. Independent long-term monitoring at the larger Shanghai site will matter as capacity grows toward the planned 500-megawatt cluster.

A 500-Megawatt Cluster Signals a Bigger Subsea Bet

The current site is a first step toward a far larger plan.

›Partners have signed an agreement to develop a 500-megawatt underwater data center cluster.
›That target is more than 20 times the capacity of the current 24-megawatt facility.
›The plan reflects a view that subsea computing can cut both energy costs and the freshwater strain that AI data centers place on land.
›If realized, the cluster would mark one of the largest commitments to underwater computing anywhere.

Frequently Asked Questions

Where is China's underwater data center located?

It sits off the coast of Shanghai's Lingang Special Area, about 10 meters below the surface and more than six miles from shore, surrounded by an offshore wind farm of over 50 turbines.

How does the data center stay cool without air conditioning?

Surrounding seawater circulates through radiator-equipped server racks and acts as a natural heat sink. This removes most of the power that land-based centers spend on chillers and air conditioning.

How much power does it use and where does it come from?

The facility runs at a capacity of 24 megawatts, with about 95 percent of its electricity supplied by the adjacent offshore wind farm. Operators report it uses about 22.8 percent less electricity than comparable land-based sites.

What does the facility do?

It houses close to 2,000 servers across 192 racks running AI model training, big data work, domestic large language model development, and 5G network tasks. Named clients include China Telecom and LinkWise.

Are there environmental concerns?

Yes. Releasing server waste heat into the ocean can alter water chemistry and affect marine life. HiCloud says water near its earlier Hainan site warmed less than 1 degree Celsius, but long-term monitoring will matter as capacity scales up.

China's offshore wind-powered underwater data center turns two of the biggest costs in AI computing, cooling power and freshwater, into design advantages. With a 500-megawatt cluster already planned, subsea computing is shifting from experiment to commercial strategy, though waste-heat effects on marine life remain the key open question.