Google relies on “evaporative cooling,” which evaporates water to cool the air around the processing units stacked inside data centers, according to its environmental report. The most common systems, known as computer room air conditioners, are energy intensive. Evaporative cooling uses less energy, but the process requires more water. Operators will often embrace the thirstier approach because it’s less expensive, said Cook from Stand.earth.
Google has paid more attention to water use in recent years. It relies on recycled water or seawater where it can to avoid using drinking water or draining local supplies. Google also says it saves water by recirculating it through cooling systems multiple times. In Mesa, the company is working with authorities on a water credits program, but said it’s too early to share more details.
From 2007 to 2012, Google used regular drinking water to cool its data center in Douglas County, just outside Atlanta. After realizing the water “didn’t need to be clean enough to drink,” the company shifted to recycled water to help conserve the nearby Chattahoochee River. It’s difficult to use similar approaches for other data center locations because the required technology isn’t always available, according to the company.
https://time.com/5814276/google-data-centers-water/
https://www.cnbc.com/2021/06/21/drought-stricken-communities-push-back-against-data-centers.html?mod=djemCIO