Air Cooling Cut Total Water Use 44% in Michigan Data Center Model

An air-cooled chiller reduced modeled total annual water consumption by 44% at a hypothetical data center in southeast Michigan, despite increasing electricity use and water consumption tied to power generation. The scenario modeled a 200-megawatt IT-load facility in Oakland County over a year of operation.

Direct water consumption at the facility fell 97%, from 6.45 million cubic meters a year to 0.21 million. Electricity demand rose 32%, from 3.08 terawatt-hours (TWh) to 4.06 TWh. The added demand increased modeled indirect water consumption at electricity-generation facilities by 32%, from 4.48 million cubic meters to 5.91 million.

The increase in generation-related water use did not offset the modeled on-site reduction. Total annual consumption fell from 10.93 million cubic meters with a water-cooled chiller to 6.12 million with an air-cooled chiller.

The distinction matters because direct consumption is water used at the data center, primarily for cooling. Indirect consumption occurs at power-generation facilities supplying the center’s electricity. The two measures capture water use in different parts of the system, and the model’s total combines them.

A hybrid system produced a middle result, with modeled electricity use of 2.76 TWh and total water consumption of 7.19 million cubic meters a year. It used 3.20 million cubic meters directly and 3.98 million indirectly, and operated in airside-economizer mode for 25% of the year.

The results are estimates for a hypothetical facility, not measurements from an operating data center. The model used estimated cooling performance and represented Michigan’s electricity grid as four regions. Actual water impacts can vary with local generation and water conditions.

For national context, U.S. data centers consumed about 66 billion liters of water directly in 2023, while their electricity use was linked to nearly 800 billion liters consumed at power plants. Those figures describe U.S. data-center water use in 2023.