Want to wade into the snowy surf of the abyss? Have a sneer percolating in your system but not enough time/energy to make a whole post about it? Go forth and be mid.
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Any awful.systems sub may be subsneered in this subthread, techtakes or no.
If your sneer seems higher quality than you thought, feel free to cut’n’paste it into its own post — there’s no quota for posting and the bar really isn’t that high.
The post Xitter web has spawned so many “esoteric” right wing freaks, but there’s no appropriate sneer-space for them. I’m talking redscare-ish, reality challenged “culture critics” who write about everything but understand nothing. I’m talking about reply-guys who make the same 6 tweets about the same 3 subjects. They’re inescapable at this point, yet I don’t see them mocked (as much as they should be)
Like, there was one dude a while back who insisted that women couldn’t be surgeons because they didn’t believe in the moon or in stars? I think each and every one of these guys is uniquely fucked up and if I can’t escape them, I would love to sneer at them.
(Credit and/or blame to David Gerard for starting this.)
So the water usage of data centers/ai has long been controversial (either a huge issue/a non issue/distraction depending on who you ask) and the lack of real numbers around it made it hard to know more (but data center owners keeping it a secret made it sus). But now the stats of one google data center have been released due to legal pressure. 2-8 million gallons a day
Genuine questions borne of ignorance:
When they say "using" water, is this water that has to be actively removed from the supply each day, or does this number just say how much water is circulating in the center? I'm assuming it doesn't all disappear, or does a lot of it end up released as steam or piped away as contaminated water or something?
The data center nearest to me uses sea-water, but I have no idea how much. And it doesn't seem to put out steam or dump bad water back into the sea (not that I could tell if they were doing that).
I totally understand the electricity resource issue for data centers but the water usage thing confuses me, because I assumed it would be for cooling and therefore mostly contained and recirculated. With the exception of predictable maintenance issues like leaks and waste from mineral scale or algae, I don't understand why this water would need to disappear, or why they would need to use potable water from the outset.
Admittedly my mental model is based on consumer CPU water-cooling setups at an imagined industrial scale. What am I missing?
the thing you're missing is scale. what you're describing is overgrown car radiator type scheme, and it works up to some couple MW if need be. when you have access to sea, or large river, you can just use that water as a coolant and dissipate some couple GW this way. this is the reason why so many nuclear powerplants are on seashore. because sea is generally very big [citation needed] temperature increase is slight and mostly harmless in usual cases
inland, in absence of large river, the other way to provide cooling is by evaporation of water. one form is to take that oversized car radiator and spray water on it, water evaporates taking away some heat. this arrangement allows for no-added-water operation in low load conditions. in principle this means that lowest possible temperature is not air temperature, but instead it's wet bulb temperature, which is always lower, and difference is greatest when air humidity is low. in practice this doesn't allow to reach this lower temperature, but the other approach does. for bigger scale still, instead of using heat exchanger, water is dripped in a tower of some shape and air is moved in some way against it. small part of water evaporates, and the rest, now cooled down, is collected at the bottom. this is how these large cooling towers near coal or nuclear powerplants work, but so do smaller towers that rely on fans instead of chimney effect. extra water is always needed, and temperature closer to wet bulb temperature is achieved in all load conditions. rarely used alternative is to make an artificial lake, and allow for evaporation from water surface
notice that if water is evaporated, it'll leave whatever is dissolved in evaporator part, which means it has to demineralized at all times. in practice it means that some part of evaporated water is treated continuously by reverse osmosis, and the less saline input water is, the easier and more energy efficient it is to do it
the thing with heat exchangers is, without water evaporation, that they have some constant thermal resistance. if you want to dissipate more heat, you need more of heat exchanger, or alternatively have to allow for higher temperature. the former means more metal needed, the latter means limits to other parts of coolant loop, or using heat pump to cool down silicon, while increasing temperature of coolant. both of these mean extra capex and/or energy use, but evaporating water is cheap, so it's done instead. it doesn't help that one of dc ratings is ratio of how much energy gets into dc to how much energy powers actual silicon. evaporating water does not add to energy use, so designs chasing this rating are likely to use that solution
Ok, now I understand, thanks for the crash course on dc cooling!
I assumed scale was my issue but having only second-hand knowledge of coastal larger-scale cooling systems was the big part of my problem. Then I couldn't understand why they were building them inland, especially with the mineralization issue when drawing from inland reservoirs. So I thought that might be a tax jurisdiction reason, plus comparative cost of metal or pump heat exchange setups, especially because Altman said they weren't using evaporative cooling (not that he's a trustworthy source).
But this made it all click:
They were always optimizing for the cost, but I didn't know about this regulation. Water usage is probably either absent from the regulations or a minimal contribution to it, so they've used it as the trade-off without adequate (if any) modeling for impact. They've probably since done a little of that and found it's pretty catastrophic. A little extra reading indicates the 2-8 million gallons is the supply per day by the county, and not total (re)circulating water in the dc, which implies evaporative cooling and aligns with what you're saying about it being the cheapest solution.
Cool, everything is yet again awful, but at least it makes sense on some level. I have been educated, and I again thank you for your effort in that.
it's not regulation, it's a metric that looks nice to investors. but also lower energy use means lower cost
This is fresh water coming into the datacenter. A datacenter uses water for air conditioning; imagine spraying water on a screen door when wind is blowing through it and you'll have a good intuitive idea of the dynamics. Most of the water is recaptured and used for several sprays before it evaporates away. To force wind through the screens, they use windcatchers, tall towers which induce wind inside the building.
This is completely different from water-cooling gamer setups. It's more like a weather system. Water usually needs to be added because the datacenter is located in a dry biome; air conditioning doesn't thermodynamically work if the air is too dry. This is actually really delicate; too much water will cause clouds to form inside the building!
Ok that makes sense, thanks for the explanation!
The data center nearest to me works a bit differently, I know they use sea-water for their HVAC because they share the pipes with other buildings using it for the same purpose, and I was lucky enough to get a tour of the system in one of those buildings a few years back. It's multi-storey so perhaps I simply didn't notice the windcatcher parts in the architecture.
But that obviously means it's also near the coast and therefore not the driest biome from the start. I don't doubt it still impacts the ecosystem but at least it's not draining the potable reserves at the same time. To me this begs the question of why they're building these data centers so far inland.
As a side note, it's pretty amazing we still do the windcatcher setup. They've always been fascinating to me, but I can't help but be amazed they're still relevant even in the highest tech buildings.
I don't know the answers to a lot of these questions, I assume they heat up the water, and dump it back into the rivers, which causes some disruption to the local ecosystem. Which is fine if you do it in small amounts, but it will disrupt things. (powerplants have the problem for example that some flora/fauna gets attracted to these more warmer waters, risking clogs and more. (so a datacenter does this twice, first via the powerplant generating power, and then to cool the datacenter).
There is also the issue of contamination, while I assume they don't put extra dirty things in the water, this is not a guarantee, nor will every municipality/gov just go with the assumption that it is clean, I assume that in some places this cooling water will need to be cleaned extra as industrial waste. Esp when there are some odd laws interacting. (I know some of those laws re waste and what counts as waste interact weirdly in .nl causing weird busywork during roadwork so they don't run into extra costs by accidentally letting the waste count as a different class of waste).
But yes, I think they do not recirculate, and just pump it round and dump it back into the river directly (so no evaporative cooling where the water goes into the air, which you had at some powerplants, the big towers), and I assume they don't use lead pipes so the water isn't very contaminated. But these sort of processes do put a strain on the water quality. (In .nl we have some problems with river water quality because our big rivers come from industrial areas of other countries, (Germany mainly)).
I mostly posted it so that we now at least have some indication of the amounts we are talking about, as tech companies are very tight lipped about this. But as somebody who knows nothing, I do not know all the implications of it. I am however suspicious, due to a combination of natural paranoia, them being very mum about it, and me not trusting the big tech places.
But yeah, if they use up 90% of the daily flow of a river and heat it up, that will absolutely not be good for the local ecosystem. And any industrial site downstream who also wanted to use the water for cooling now also in trouble.
Bit like the same reason I posted about protonmail, more an FYI than a sneer (not a huge shock that eventually protonmail would reveal the data if forced by their gov, they always said they would do this, but it is an important thing to take into account if you worry about privacy).
Thanks for giving it a go, I mostly hoped there might be someone who had some experience in the area who could shed some light. But the numbers were certainly interesting. Then the pivot to AI post went up 30 mins after I posted and shed a little light on the while thing too.
It would seem odd to put the heated water back instead of cooling it off and re-using, but I don't have faith in any kind of sustainability designed or built into the system, so that would make sense for impact.
If they're being quiet about it, it means one or two things. Either they're actually considering it proprietary new tech, but there would almost certainly be patents filed somewhere for that case, and/or they have something they're not proud to announce. I have no idea what words would be used for a patent here, being an area well outside my expertise, but I've not heard any patents mentioned, so I'm going to assume it's squarely the shame reason.
The protonmail thing... I just assume nothing I do is private and keep all my services as decoupled as possible to make me more annoying to track down, should the situation arise that I become somehow not boring. One day I'll set up something more private and annoying, but I have a long list of todos that never become todones...
This is comparable to the amount of water used by cherry farmers near Google's site in The Dalles, who (according to my napkin) use somewhere between 2-8x what Google uses. This isn't that much water for the Columbia River though; on an average day, it has enough flow in less than a minute to provide for both the cherry farmers and Google all day. However, it would be a big problem for a smaller river. (Interestingly, while fresh water is essential for datacenters, Google originally desired that site because it was cheap land next to cheap hydroelectric power.)
I was trying to put this into perspective by comparing this to the flow rate of the Des Plaines river. At the high end, 8 million gallons a day is something like 12.4 cubic feet per second constantly. Currently the Des Plaines has a discharge rate of 86-87 cubic feet per second, so a bit above 14% of the Des Plaines per data center.
Fuuuuck, that's a lot. Thanks for doing the maths