AI uses less water than the public thinks • Hacker News Board

Re: AI uses less water than the public thinks

#61

Post by catlikesshrimp » Fri, May 01, 2026, 7:08 PM UTC

bee_rider wrote: post #38

I don’t really get the water concerns in datacenter cooling. Even if a lot of water was used for cooling with every prompt (which he argues against here, but, even if )… water “used up” by cooling just comes out a little hotter, right? Maybe evaporated. Then it’ll come back in the form of rain. This isn’t an industrial chemistry process that leaves some toxic waste in the water. Or an agricultural one that puts water…

I honestly don't know if you are an AI atroturfing bot. No, I am not being sarcastic. Given this is the top comment and there is no reply, here you go

For a pre-chewed eli5 overview, check this: https://www.eesi.org/articles/view/data-centers-and-water-co...

A responsible human must always verify information. I DW as "secondary l" information source. For instance https://www.dw.com/en/why-does-ai-need-so-much-energy/video-...

tldr: chip immersion uses less water but is more expensive. Water evaporation is the opposite. Datacenters will use the cheapest they can get away with. Water is scarse; evaporated water is as unavailable as contaminated water. Read the information sources.

Re: AI uses less water than the public thinks

#62

Post by loeg » Fri, May 01, 2026, 7:08 PM UTC

munk-a wrote: post #12

htx80nerd wrote: post #6

The author uses a measurement I'm not familiar with so I used AI to translate it. >Using the broader initial AI water use estimate of 32,000 acre-ft/year to 290,000 acre-ft/year Note : 1 acre-foot is approximately equal to 325,851 gallons. AI : That estimate converts to approximately 10.4 billion to 94.5 billion gallons per year. Ya 10 billion gallons of water (low estimate) is totally nothing. Thx for this informati…

To be fair to people's objections - agriculture is significantly more important than AI model training when it comes to improving the average standard of living - and to be fair to model training a lot of the water usage in agriculture is used on extremely water inefficient crops. Water usage is, in my opinion, a fair reason to object to AI datacenter placement and growth - but in the arena of public opinion it's mor…

Marginal agricultural water use is alfalfa / nut farming in the desert and ethanol corn, not products consumers actually care about. Consumers aren't clamoring for E15 fuel over E10.

Re: AI uses less water than the public thinks

#63

Post by traderj0e » Fri, May 01, 2026, 7:09 PM UTC

bee_rider wrote: post #38

I don’t really get the water concerns in datacenter cooling. Even if a lot of water was used for cooling with every prompt (which he argues against here, but, even if )… water “used up” by cooling just comes out a little hotter, right? Maybe evaporated. Then it’ll come back in the form of rain. This isn’t an industrial chemistry process that leaves some toxic waste in the water. Or an agricultural one that puts water…

It doesn't come out a little hotter, it gets evaporated in cooling towers. Same result as any other water usage. Cooling towers can't use seawater either. Most datacenters are in places where fresh water is abundant anyway, but some are not.

Anyway agricultural water usage is way worse in California.

Re: AI uses less water than the public thinks

#64

Post by AustinDev » Fri, May 01, 2026, 7:09 PM UTC

loeg wrote: post #43

bee_rider wrote: post #38

I don’t really get the water concerns in datacenter cooling. Even if a lot of water was used for cooling with every prompt (which he argues against here, but, even if )… water “used up” by cooling just comes out a little hotter, right? Maybe evaporated. Then it’ll come back in the form of rain. This isn’t an industrial chemistry process that leaves some toxic waste in the water. Or an agricultural one that puts water…

The absolute strongest complaint is that DCs consume treated, potable water, which is less abundant / easily re-created than any old non-potable source. (Of course the easy solution here is DCs just ingest / treat their own non-potable source. Or utilities charge rates sufficient to price in the externality of drawing down more potable water. The economics still work for DCs if they need to treat their own water -- t…

Why don’t data centers use gray water more often? Wouldn’t that be better for basically everyone?

My guess is it’s some combination of the infrastructure not existing, the distribution being bad, and the treatment costs not penciling out.

But that feels like the kind of thing municipal utilities could solve with pricing. Potable water should probably be priced differently for residential use than for big commercial/industrial users, in a way that pushes them toward non-potable sources wherever possible.

A fun Texas water fact I always bring up: the entire state’s monthly freshwater use is roughly a week of freshwater inflow into the Chesapeake Bay. Texas would be the 8th-largest GDP in the world if it were a country, and its whole monthly freshwater demand is basically a few months of water that the Chesapeake just dumps into the ocean. (Of course, estuaries make use of the water so it's not just wasted but it's illustrative imo)

Another fun comparison point is yearly Texas uses 0.08% the volume of the Great Lakes in freshwater but ~ 30-50% of the volume of all the lakes in Texas.

We've got a lot of water but it's not distributed evenly and we should probably build some sort of water pipeline eventually so water rich states can sell to water poor states.

Again, this is all just speculation by someone who knows not a damn thing about municipal water management.

Re: AI uses less water than the public thinks

#65

Post by hnav » Fri, May 01, 2026, 7:09 PM UTC

mrinterweb wrote: post #9

If data center water use is such a concern, why not require that data centers invest in closed-loop cooling systems? By closed-loop, I'm talking about re-condensing evaporated water and allowing the water to cool. Cooling the water would be more expensive in hotter environments, but still achievable. These data centers seem to have wild amounts of money for investment, why not just mandate conservation requirements?

The tradeoff is power vs water. Water is currently cheaper.

Re: AI uses less water than the public thinks

#66

Post by sublinear » Fri, May 01, 2026, 7:10 PM UTC

bee_rider wrote: post #38

I don’t really get the water concerns in datacenter cooling. Even if a lot of water was used for cooling with every prompt (which he argues against here, but, even if )… water “used up” by cooling just comes out a little hotter, right? Maybe evaporated. Then it’ll come back in the form of rain. This isn’t an industrial chemistry process that leaves some toxic waste in the water. Or an agricultural one that puts water…

I have also wondered this and came to a similar conclusion about the politics.

This whole time I've been wondering how it's possible that people don't realize how common evaporative cooling is for much larger buildings that are far more numerous than these data centers, and especially in dry climates where drought is common.

Re: AI uses less water than the public thinks

#67

Post by traderj0e » Fri, May 01, 2026, 7:11 PM UTC

bigmadshoe wrote: post #56

Did anyone find it weird that the author uses AI itself to perform the calculations? Seems like a very poor quality piece

I stopped reading at the crappy ChatGPT comic that shows "water usage" as some pipes pouring water and others pumping it in. How trustworthy is the text going to be after that?

Re: AI uses less water than the public thinks

#68

Post by mbesto » Fri, May 01, 2026, 7:11 PM UTC

mrinterweb wrote: post #9

If data center water use is such a concern, why not require that data centers invest in closed-loop cooling systems? By closed-loop, I'm talking about re-condensing evaporated water and allowing the water to cool. Cooling the water would be more expensive in hotter environments, but still achievable. These data centers seem to have wild amounts of money for investment, why not just mandate conservation requirements?

> These data centers seem to have wild amounts of money for investment, why not just mandate conservation requirements

This IS the complaint.

Re: AI uses less water than the public thinks

#69

Post by parsimo2010 » Fri, May 01, 2026, 7:11 PM UTC

Comparing water usage of AI to agriculture and cities is a little misleading. The cities' water usage is to keep people alive with basically mandatory things, like hygiene, and drinking. Agricultural water usage is required because we have to eat to live. Don't compare something optional to something mandatory.

Instead, compare AI water usage to that of optional things in a city, such as car washes and water parks. Or compare AI water usage to that of what it would take a human to do a comparable task (what does it take to keep a human alive for a few hours compared to running a 15 minute long task to write a report with AI?). While AI water usage might still not look that bad, it would be a more honest comparison.

Re: AI uses less water than the public thinks

#70

Post by legitster » Fri, May 01, 2026, 7:11 PM UTC

> Using the prompt, “How much water is likely to evaporate from data centers in California per year, assuming they are all using mostly evaporative cooling?” several free AI websites provided ranges of estimates, below. These AI also can provide ranges and sources for calculation assumptions.

Data centers with closed loop cooling systems are absolutely built all of the time. Total evaporative cooling has the advantage of being more power efficient (and therefor cheaper) - the only reason they bother with total evap is because the water is being offered plentifully and cheap.

People have no reality of how cheaply priced industrial water is in this country. My parents had a cherry orchard and their annual water bill was $100 an acre per year for as much as they wanted. Which is why the water consumption for data centers is only still a fraction of what we lose to evaporation from inefficient spray irrigation.