The Newest Thing on the Seafloor Isn’t a Wreck, It’s a Data Center
We ask a lot of the water. It feeds us, floats us, carries our freight, and gives us somewhere to adventure and explore. Water also provides temperature stability because it absorbs and releases heat more slowly. Air heats and cools much faster than water so in coastal regions water keeps temperatures cooler in the summer and warmer in the winter. Water’s high specific heat capacity (it takes more energy to change water’s temperature) allows it to be used for many cooling purposes. Water can cool our bodies with a quick summer plunge, keep boat engines from overheating, or be used in industrial applications to cool factories and power plants. Water’s unique thermal capabilities are now being tested as a method to cool the world’s computers.
Off the coast of Shanghai, in the middle of an operational offshore wind farm, the world’s first wind-powered underwater data center began full commercial operations in May 2026. From the surface, you see only the tip of the structure standing among the turbines. Below it, sealed modules holding roughly 2,000 servers sit about 10 meters/30 feet down, cooled by the sea itself.
Cool tech? Absolutely. But with the vast expansion of data centers driven by AI, could this type of cooling, over time, do more harm than good? Anyone who spends time on the water, and even those who don’t, must wonder what the eventual consequences of data center heat exchangers are for the planet and the waters we boat, fish, and live on.
Unless something changes radically, the data centers are coming whether we like it or not. The AI boom appears to be real and every one of those servers throws off heat around the clock. On land, that heat gets dumped into the air around the facility while the cooling systems drink deeply from freshwater supplies that people and agriculture depend on.
Ocean cooling is not a magic fix. It is a tradeoff, one that potentially moves the thermal burden out of stressed watersheds and into the sea. At this time, it is unclear whether this is a better solution. Realistically it is a compromise between competing environmental costs, and it deserves scrutiny. Small amounts of heat added to the oceans vs. the loss of freshwater is a tradeoff worth analyzing and we all should try to be aware and weigh in when it makes sense.
Why stick servers in the ocean?
The use of underwater ocean servers can conserve fresh water. The scale of what land-based cooling using fresh water goes through is bigger than most people realize.
In a conventional facility, cooling infrastructure can account for approximately 20 to 40 percent of a data center’s energy consumption, depending on the design, climate, and workload. The water itself adds up fast. Some of the largest hyperscale data centers can consume several million gallons of freshwater per day, though actual usage varies widely by facility, cooling design, and climate. Think of it as the water supply for a town of 10,000 to 50,000 people used for cooling computers. A study in the journal npj Clean Water (an open access, international, peer-reviewed journal dedicated to publishing high quality research relevant to all aspects of the sustainable supply of clean water) found that in some cases, more than half of that water comes straight from potable supplies, and fewer than a third of operators even track how much they use.
The United Nations University warned that high-growth AI adoptions and data centers worldwide could consume 2.45 trillion gallons of water a year by 2030. To put this into perspective, it is roughly the annual household water needs of all of sub-Saharan Africa. That amount of water would be used to keep servers comfortable. Their report flags land use noting the growing footprint too, since these facilities can sprawl across hundreds of acres apiece.
Many big cloud and AI players are trying to solve the problem from land, with zero-water cooling designs, watershed replenishment pledges, and a race toward carbon-free power (see sidebar). Some of that technology, especially closed-loop systems that cool at the chip level without using any water, could prove to be the better answer in the long run. If those designs deliver at scale, the case for putting servers in the ocean gets weaker. Until then, ocean cooling may remain a viable option.
The one thing all these tech giants have in common with China’s underwater experiment is the numbers, while impressive, are largely self-reported. Independent verification is the next frontier and is more necessary than ever.
China’s answer may be the boldest of the bunch: instead of competing for freshwater resources, put the servers where the coolant already exists, in the ocean.
A look inside the underwater data center
The Shanghai Lingang project’s numbers are worth a closer look. The $226 million facility developed by HiCloud Technology with state-owned China Communications Construction sits about six miles offshore. Its planned capacity is 24 megawatts, about what 20,000 American homes draw, packed into 198 server racks.
The cooling concept is simple. Sealed copper piping circulates seawater across radiators behind the racks and carries the heat away in a slow, constant flow. No chillers and no cooling towers, and the developers say the design eliminates freshwater use entirely. They also claim it cuts electricity use by more than 20 percent compared with the same facility on land and shrinks the land footprint by over 90 percent.
The power is the other half of the story. More than 50 offshore wind turbines surround the site, feeding it through subsea cables and, according to project developers, supplying an estimated 95 to 97 percent of its electricity. The juice gets used a few hundred yards from where it is generated, which is about as efficient as renewable energy gets.
Haven’t we seen this before?
Sort of. Microsoft sank a shipping container-sized pod holding more than 800 servers off the coast of Scotland in 2018 under the name Project Natick. When they hauled it up two years later, the sealed, nitrogen-filled vessel had suffered a fraction of the server failures seen on land. Nitrogen does not corrode like oxygen, and no technician ever bumped a rack. Microsoft shelved the program anyway, but the data was out there, and China ran with it. HiCloud tested its own modules off Hainan Island starting in 2022. Shanghai is betting that the idea can be commercially successful on a larger scale.
Microsofts Project Natick photo courtesy of Microsoft 
Natick Retrieval photo courtesy of Microsoft
What happens to the fish?
For people concerned about fish and seawater temperature rising this is the most important part. All that server heat has to go somewhere, and where it goes is the surrounding sea.
Marine scientists have legitimate concerns. Studies of thermal discharge from power plants show warm outflows can lower dissolved oxygen, shift pH, and change sediment chemistry, thinning out the life nearby. Plenty of species depend on stable temperatures to spawn, feed, and migrate. The worry intensifies during marine heat waves, when fish already stressed by warm water encounter even warmer outflows. Add construction noise, electromagnetic fields from the cables, seabed disruption, and the chance of attracting invasive species, and there is real need for concern.
The operators tell a calmer story. HiCloud says monitoring at its Hainan site shows that the water around the modules is warming by less than one degree Celsius (33.8 Fahrenheit), and that schools of fish have moved in, using the structures for shelter. Any angler who has worked a wreck, a bridge piling, or an oil platform knows exactly how that goes. Hard structures often become habitat or aggregation points for marine life.
Some independent voices think it is worth the risk. Rick Stafford, a marine biology professor at Bournemouth University, doesn’t think the localized warming is likely to have far reaching impacts. Other experts see the risks as manageable but stress the need for continued monitoring.
This all comes with one caveat. Nearly all the numbers so far come from the company itself, and a 24 megawatt pilot is significantly smaller than the 500 megawatt undersea facilities already being sketched out. Nobody has published an estimate of what a facility that size would do to the surrounding water, let alone the even bigger ones that may follow if the technology appears to be working well. The only hard numbers we have come from installations a fraction of that scale, in different oceans, under different conditions. Independent, long-term monitoring is the right ask before server pods become a fixture of coastal waters. The ocean cooling these computers is, after all, already warming on its own.
Coming soon to a coastline near you?
If the Shanghai servers perform well, expect proposals elsewhere. Many of the same offshore wind lease areas being developed along the Atlantic coast could eventually host similar infrastructure, which means the concept may not stay distant for U.S. boaters. New pods could mean new exclusion zones on the chart but also new structure for fish to gather around. They would raise fresh questions about navigation, fisheries, marine habitat, and who keeps an eye on the seabed.
AI is on the rise and all those data centers that make it work use a lot of energy which requires cooling. How the energy is sourced, where these computer banks are located and how to cool them are serious questions that still need to be answered. Environmental concerns regarding freshwater consumption and/or heat pollution in the oceans must be addressed before data center induced heat spikes cause irreparable damage. As boaters, we know how precious our water resources are and we should keep a close eye on this situation.
We ask a lot of the water, and now we may be asking it to cool our computers too. How this shakes out depends on whether the monitoring keeps pace with the ambition. For now, somewhere off Shanghai, the turbines are spinning, the servers are humming, and the fish, reportedly, are moving in.
Are there better solutions that don’t use water or use less of it?
Many tech giants are attacking data center water and energy use from different angles. While much of this information is just PR from the companies themselves it is interesting to see some of the solutions being touted.
Microsoft went underwater first with Project Natick, then shelved it and changed course. Since August 2024, every new Microsoft data center design uses closed-loop, chip-level cooling that consumes zero water, saving more than 33 million gallons per facility each year. The first zero-water sites will come online in Phoenix and Wisconsin.
Google recently announced that it will use air cooling in at-risk watersheds. It will shift toward reclaimed wastewater and replenishing 120 percent of the water its data centers consume by 2030. It says it restored more than 7 billion gallons in 2025 across 165 watershed projects.
Amazon Web Services (AWS) has the most established program. It targets net-zero carbon by 2040 and water positive by 2030. AWS cut its water use to 0.15 liters per kilowatt-hour (the industry average is 1.9) and signed four nuclear energy deals in 2024 to power data centers with carbon-free electricity. (How the nuclear power is cooled is another question.)
OpenAI, the company behind ChatGPT, says its Stargate developments are being designed to minimize impacts on local energy infrastructure through dedicated power investments while prioritizing closed-loop, low-water cooling systems. Its new Wisconsin campus aims to be water positive through local restoration projects.
Anthropic, maker of the Claude AI assistant, committed in February to covering the electricity cost increases its data centers create for ratepayers and to deploying water-efficient cooling, though it has published less environmental data than its peers. It is a bit unclear how they are going to manage this and what the actual impacts will be.
Works Cited
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