Nvidia wants to reduce water use in data centers, but that’s not the same as fixing the water problem in AI

Nvidia just announced a warm-water cooling system that it says can significantly reduce the amount of water a data center uses — eliminating “almost all water use” inside the data center, an Nvidia executive said in a report. press release.

“The challenge of water consumption in data centers has largely been solved,” Nvidia chief sustainability officer Josh Parker said recently. He said Axios.

But that’s just part of the water story. As long as AI data centers run on fossil fuels, technology companies are the perfect choice Increasingly made — The savings stop at the data center walls.

The fundamental issue is how Nvidia measures data center water use. According to its blog post, the company is essentially drawing a line around the data center. Anything on the inside is counted, and anything on the outside is ignored.

To be fair, Nvidia’s system appears to be delivering on its promise at the facility level — the coolant operates in a closed loop, is filled once and recycled for the life of the facility, meaning no new water is consumed to cool the chips. The company says that in favorable climates, this can result in a 100% reduction in on-site water use.

TechCrunch has asked Nvidia to clarify the matter, and we will update this article if we hear back.

The problem is that water use outside the data center — primarily in electricity generation and chip manufacturing — can occur double or Triple The facility’s total water footprint. This means that Nvidia’s solution handles about a quarter to a third of the total water consumption in AI data centers.

The new system is smart, pumping coolant to the racks at a temperature of 45°C (113°F). That’s hot for humans but not for computer chips. After passing through the server, the cooler exits at a temperature of 55 degrees Celsius (131 degrees Fahrenheit), taking a significant amount of heat away from the hardware, Nvidia said.

At this temperature, outside air in most climates can draw heat from passive radiators without evaporative cooling or, in some cases, fans. A data center without fans or coolers will not only use less water, it will also be more efficient and quieter.

But no data center can operate without an electricity supply, and many types of power plants are themselves major consumers of water.

Fossil fuel power plants are one of the largest users of water in the United States, consuming 2.7 billion gallons per day. According to To the USGS – mostly for evaporative cooling. Natural gas power plants use 1.17 liters of water for every kilowatt-hour of electricity they generate, according to a Recent study. Coal plants also consume more water, using 2.2 liters per kilowatt-hour. Fossil fuel power plants combined generate about half of all data center power today. According to To the International Energy Agency.

Hydropower dams, which provide about 10% of data center power, do not consume water in the same direct way, but evaporation from their reservoirs amounts to 6.8 liters lost for every kilowatt-hour generated. Geothermal energy, the source that technology companies are beginning to explore, varies widely, and may be higher or lower depending on the specific technology. Some geothermal startups, such as Fervo, have done just that pledge To use mostly “degraded” water that may otherwise go unused.

Wind and solar, on the other hand, use very small amounts of water, about 0.01 liters and 0.03 liters per kilowatt-hour, respectively — numbers that include the water needed to manufacture and clean solar panels.

While renewables provide an increasing share of new electricity capacity, natural gas and coal are expected to provide more than 40% of the new electricity needed to meet data center demand through 2030, according to IEA projections. Without major changes in this direction, data centers will continue to consume large amounts of water, regardless of what Nvidia does within their walls.