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Data Centers Work To Reduce Water Usage
miller60 writes "As data centers get larger, they are getting thirstier as well. A large server farm can use up to 360,000 gallons of water a day in its cooling systems, a trend that has data center operators looking at ways to reduce their water use and impact on local water utilities. Google says two of its data centers now are "water self-sufficient." The company has built a water treatment plant at its new facility in Belgium, allowing the data center to rely on water from a nearby industrial canal. Microsoft chose San Antonio for a huge data center so it could use the local utility's recycled water ('gray water') service for the 8 million gallons it will use each month."
It doesn't really work for a couple reasons. First, heat doesn't get destroyed in the ground or wicked away (unless you have an underground river, which changes the whole story), it is stored. This is awesome for a building that pumps heat into the ground in the summer and then needs to pull it back out in the winter, but sucks for a datacenter that is pumping out MW of heat 8760 hours a year. Second, massive quantities of heat. A rule of thumb would be 200 feet of well per 3.5 kW of cooling. A modest datacenter is around 15 MW of waste heat, so you need 860,000 linear feet of well (with double that much piping making a U down each well). And after a year you're screwed anyhow because of issue #1.
Datacenters, like 99% of facilities with large cooling loads, evaporate water to reject the heat. The water comes in and is essentially boiled off through devices called cooling towers. You reject 1000 btus per pound of water evaporated - there is no more efficient way to reject heat. Not coincidently (if you believe in evolution), your body rejects heat the exact same way.