Nvidia has unveiled a warm-water cooling system designed to significantly cut down on water usage in data centers — claiming to eradicate “virtually all water usage” within the data center, as stated by an Nvidia official in a press release.  

“The challenge of water consumption in data centers is largely addressed,” Josh Parker, Nvidia’s chief sustainability officer, recently shared with Axios.

However, this aspect is just a portion of the overall water narrative. As long as AI data centers rely on fossil fuels — a decision increasingly made by tech firms — the reductions cease at the perimeter of the data center.

The fundamental concern lies in how Nvidia gauges data center water consumption. Based on its blog entry, the company essentially delineates a boundary around the data center. Anything within this boundary is counted, while anything outside is disregarded.

To be fair, Nvidia’s system seems to fulfill its facility-level promises — the coolant circulates in a closed loop, filled once and recirculated throughout the facility’s lifespan, thus requiring no additional water to cool the chips. In favorable environments, the company claims this can lead to a 100% reduction in onsite water usage.

TechCrunch has reached out to Nvidia for clarification, and this article will be updated if a response is received.

The issue is that water usage beyond the data center — mainly for electricity generation and chip production — can double or triple the overall water impact of a facility. Thus, Nvidia’s solution effectively addresses about 25% to 33% of AI data centers’ total water consumption. 

The new cooling system is innovative, delivering coolant into racks at 45°C (113°F). This temperature is high for humans but not for the chips. After passing through a server, the coolant exits at 55°C (131°F), Nvidia stated, effectively transferring a significant amount of heat away from the hardware. 

At this temperature, the external air in most climates can draw heat from passive radiators without the need for evaporative cooling or, in some cases, fans. A data center devoid of fans or chillers would not only utilize less water but also be more efficient and quieter. 

Yet, no data center can function without a power supply, and numerous types of power plants are themselves considerable water consumers.

Fossil fuel power plants rank among the largest water consumers in the U.S., using 2.7 billion gallons daily, as reported by the U.S. Geological Survey — primarily for evaporative cooling. Natural gas plants consume 1.17 liters of water for every kilowatt-hour of electricity generated, according to a recent analysis. Coal facilities are even more water-intensive, utilizing 2.2 liters per kilowatt-hour. Fossil fuel power plants together supply approximately half of the power used in data centers today, according to the IEA.

Hydropower dams, which provide around 10% of the power for data centers, do not consume water in a direct manner, but evaporation from their reservoirs leads to 6.8 liters lost per kilowatt-hour produced. Geothermal energy, a source that tech companies are beginning to investigate, varies significantly — it can be higher or lower depending on the specific methods used. Some enhanced geothermal startups, such as Fervo, have committed to using mainly “degraded” water that would otherwise remain unused.

On the contrary, wind and solar energy utilize vanishingly small quantities of water, about 0.01 liters and 0.03 liters per kilowatt-hour, respectively — these figures include the water required for manufacturing and cleaning solar panels. 

While renewable sources are contributing an increasing share of new electricity capacity, natural gas and coal are projected to account for more than 40% of the new electricity needed to satisfy data center demand by 2030, the IEA forecasts. Without substantial changes to this trend, data centers will continue to consume significant amounts of water, irrespective of Nvidia’s actions within its confines.