Thread

Most data centers refusing to say how much water, electricity they use

216 points · 199 comments · Thom2503

stingraycharles · 1790769649 · focus · HN ↗
Playing the devil’s advocate: don’t “freedom of information” laws mostly apply to government agencies? If so, why would a private company provide this information?
I personally believe at the very least the water usage is heavily overblown compared to the agriculture industry. Elecricity is a different issue, and governments should consider reporting requirements or something like that.
Being angry with datacenter providers is not the solution. And they also need to be built somewhere, and that place is probably best where electricity is abundant and/or cheap.
1. n4r9 · 1790771200 · focus · HN ↗
  > the water usage is heavily overblown compared to the agriculture industry
  Data centers tend to concentrate their water usage within urban areas, causing a strain on local resources. The value of their output is much less tangible. Their water consumption scales up around tenfold if you consider the indirect usage from generating the electricity.
  But on the other hand; yes, it would also help enormously if people ate less meat.
  1. kemotep · 1790772079 · focus · HN ↗
    Essentially, telling people to go vegan and get rid of their golf courses is going to piss them off, hence the reaction people have to being told that datacenters are more important than their comfort.
    bayindirh · 1790772637 · focus · HN ↗
    It's not black and white as it looks.
    I'm personally willing to change my life to help the planet and nature in general to the point it doesn't affect my wellbeing (as in health and safety). For me, personally, the problem is not changing per se, but people finding no amount of change enough, always moving the goalposts with "but, what if" clauses.
    The problem with datacenter water use is the state of the water leaving the data center. Agriculture and meat industry can reuse the water multiple times from cleaner to dirtier processes and return it to the nature with reasonable processing.
    The additives used by datacenters in some cases can't be filtered or processed out practically or in economically viable ways, so the water returns back as unusable, esp. if they get water from a body of water and return it with added chemicals the process gets very damaging.
    MC995 · 1790773416 · focus · HN ↗
    > The additives used by datacenters in some cases can't be filtered or processed out practically or in economically viable ways, so the water returns back as unusable, esp. if they get water from a body of water and return it with added chemicals the process gets very damaging.
    Why would any water be returned? Datacenters (and literally every industrial process that requires cooling) use water for evaporative cooling. The water evaporates, then returns as rain elsewhere.
    The only water being "returned" I can think of would be from the intermittent or continuous blowdown systems to maintain TDS levels; but blowdown is a small fraction of the water consumed and is typically returned back via the city sewer system.
    n4r9 · 1790773573 · focus · HN ↗
    Roughly 80% of the water evaporates into the atmosphere. The remaining 20% is flushed out of the system to remove mineral build-ups and sent to local treatment plants.
    BikiniPrince · 1790778183 · focus · HN ↗
    I have yet to see the standardization in that claim. Are there some reliable papers on this topic?
    MC995 · 1790780843 · focus · HN ↗
    It's complicated, and depends on the hardness of the water entering the system from the water supply as well, since blowdown is ultimately to control the level of dissolved solids in the water so it does not contrate enough to start coming out of solution. Rarely if ever is true demineralized water used in open loop cooling systems; it's simply too expensive to produce to then "throw away" into evaporation.
    The previously stated 80/20 isn't a bad general estimate, but it varies depending on the specific site. 10%-25% of makeup water being lost to blowdown is a reasonable range.
    As for papers about it, I was only able to find a few in my brief search, but they don't land on a single number since it depends on the ratio of dissolved minerals/solids in the circulating cooling-tower water compared with the incoming makeup water, which varies due to acceptability for the process and due to the incoming water quality.
    This short PDF on "Mechanical Systems Water Efficiency Management" from the EPA goes over the concepts pretty well though
    - <a href="https://www.epa.gov/sites/default/files/2017-12/documents/ws-commercialbuildings-waterscore-mechanical-systems-guide.pdf" rel="nofollow">https://www.epa.gov/sites/default/files/2017-12/documents/ws...
    This document from the US DOD (UFM 3-230-13, Industrial Water Treatment Operation and Maintenance (2026), Chapter 5) says that most cooling towers operate at 3-10 CoC, with 5-7 CoC identified as a cost-effective range. Where CoC is Cycles of concentration described in the previous PDF, and a higher CoC means less blowdown and better water efficiency, with the trade-off of a greater risk of scaling, corrosion, and biological/water-chemistry problems.
    - <a href="https://www.wbdg.org/FFC/DOD/UFC/ufm_3_230_13_2026.pdf" rel="nofollow">https://www.wbdg.org/FFC/DOD/UFC/ufm_3_230_13_2026.pdf
    Veolia also has a "Open Recirculating Cooling Systems" handbook that shows some good examples with real numbers in table 31-1.
    - <a href="https://www.watertechnologies.com/handbook/chapter-31-open-recirculating-cooling-systems" rel="nofollow">https://www.watertechnologies.com/handbook/chapter-31-open-r...
    Dylan16807 · 1790774352 · focus · HN ↗
    Additives like what?
    We're talking about water that's released in general use, right? I would expect a closed cooling loop to have some biocides but have almost none of that leave the system.
    And one datacenter had a weird bacteria that one time.
  2. [deleted] · 1790772155 · focus · HN ↗
    [deleted]
  3. SiempreViernes · 1790772320 · focus · HN ↗
    > But on the other hand; yes, it would also help enormously if people ate less meat.
    At first you had me, but then I realised it's not true if the price is building more data centres! That was just a trick to make the climate worse! Grr /s
  4. thenthenthen · 1790773362 · focus · HN ↗
    Mmm most datacenters i went to were in the middle of nowhere, sharing land with farms (and oil/gas mining)
    n4r9 · 1790774098 · focus · HN ↗
    > we demonstrate that data centers are an overwhelmingly urban phenomenon, with 97.5% of facilities situated in metropolitan and micropolitan statistical areas
    <a href="https://www.nature.com/articles/s44284-026-00487-z" rel="nofollow">https://www.nature.com/articles/s44284-026-00487-z
    Aurornis · 1790774455 · focus · HN ↗
    “Metropolitan area” is doing a lot of work. Every metropolitan area I’ve lived or worked in has had industrial areas, too. Those industrial areas have buildings that use a lot of electricity, water, or natural gas and produce a lot of noise.
    This isn’t some unusual outcome. It’s like one of those maps that purports to show one thing but really just shows population density.
    jeffbee · 1790775470 · focus · HN ↗
    Also using N as the denominator, instead of weighting by floor area?
    n4r9 · 1790775539 · focus · HN ↗
    The point is that they create a heavy and volatile local water demand on those metropolitan areas.
    BikiniPrince · 1790778052 · focus · HN ↗
    Industry uses resources and they pay for those resources at significant cost. It’s not a surprise when the pipes are enabled.
    n4r9 · 1790848829 · focus · HN ↗
    If the data center is built despite multiple demands to desist, then it may not be a surprise per se, but it can still be an unaccounted stress on local resources.
    jmye · 1790779226 · focus · HN ↗
    [dead]
    Joakal · 1790781614 · focus · HN ↗
    Most data centres in Australia (even the announced biggest one in the Southern Hemisphere) are close to a water processing plant in an industrial zone in Sydney. The same plant that supplies 85% of Sydney with drinking water. At least there's an upgrade.
    quickthrowman · 1790787110 · focus · HN ↗
    94% of the US population lives in a metropolitan or micropolitan area. There are ‘micropolitan’ areas in my state that’d I would colloquially consider rural, and there are large areas of the metropolitan area I live in that I would consider rural.
    n4r9 · 1790848935 · focus · HN ↗
    I don't dispute your lived experience. But if you have evidence to cite in contrast to what I've cited, then please do so.
  5. Aurornis · 1790774302 · focus · HN ↗
    > causing a strain on local resources
    By “strain on local resources” are you just stating the fact that they use resources? Or are you trying to imply that it causes problems for those resources?
    Companies don’t just buy land, connect to water and power, and then the utilities get caught off guard when the water system is suddenly strained by water going somewhere. There are processes for approving this before connection.
    If a new project is causing a “strain on resources” then the utility planners have failed that community.
    n4r9 · 1790775155 · focus · HN ↗
    I agree that utility planners have their work cut out to plan for data centers. It's a different paradigm than what they're used to. I think they are being caught off-guard, but it's a matter of process and infrastructure. They typically plan around averaged or linear trends, but data centers can have volatile usage spikes, and supply can depend on e.g. seasonal rainfall which is challenging to predict.
    vel0city · 1790777055 · focus · HN ↗
    Households with yards will have far more volatile water usage spikes related to seasonal rainfalls than a fully built out datacenter will.
    A recent datacenter proposal near me was going to be built on a ~35 acre site. The entire site projected to use ~300 gallons of water a day when fully operational. That's including toilets, irrigation, etc. A household on a quarter acre lot in that area often uses 10-15,000 gallons of water in a month. 35 acres cut into quarter-acre-ish lots means a bit under 140 households. We'll cut it down and say 100 after streets and what not. That lot being a neighborhood like the others nearby would probably use at least a million gallons of water in a month, about 33,300+ gallons a day.
    n4r9 · 1790780043 · focus · HN ↗
    > A typical data center uses 300,000 gallons of water each day (equivalent to the demands of about 1,000 households), but large data centers can use an estimated 5 million gallons of water each day
    <a href="https://www.brookings.edu/articles/ai-data-centers-and-water/" rel="nofollow">https://www.brookings.edu/articles/ai-data-centers-and-water...
    vidarh · 1790780452 · focus · HN ↗
    Only if allowed to. Most data centres I've used have no connection to water from the data centre halls other than to the toilets. Using open loop water cooling is a cost cutting measure it's a choice whether or not to allow.
    n4r9 · 1790848470 · focus · HN ↗
    Firstly, who is deciding whether to "allow" open loop cooling? And secondly, from what I gather, closed-loop sites require an order of magnitude more power than open-loop to run. That's still going to have a large impact on local resources, especially as around 2/3 of power plants supplying data centers are also ocated in water-stressed regions [0].
    [0] <a href="https://fieldreport.caes.uga.edu/publications/TP121/how-data-centers-impact-surface-and-ground-waters/" rel="nofollow">https://fieldreport.caes.uga.edu/publications/TP121/how-data...
    vidarh · 1790852594 · focus · HN ↗
    > Firstly, who is deciding whether to "allow" open loop cooling?
    Your government.
    And I don't know why you put allow in quotes. This is a matter of laws and regulation, so it is used in its most literal meaning:
    Forbid construction that does not account for the externalities imposed by its water and energy usage.
    > And secondly, from what I gather, closed-loop sites require an order of magnitude more power than open-loop to run.
    Are you suggesting that removing x kilowatts of input takes at least 10x killowatts?
    Or are you suggesting they spend 10x more energy on the cooling than an open-loop system?
    The latter might well be true - an open-loop system is after all trading water for energy in a very extreme way - if you have a water source with pressure the simplest water cooling system "just" routes water over radiators. In practice you'll want a bit more than that for most setups, but it can be very cheap if you can ignore the volume of water used.
    That is still a regulatory issue. You can decide which resources are critical to you in a given location, and you restrict or allow different approaches accordingly, or require funding or licensing to suit.
    > That's still going to have a large impact on local resources, especially as around 2/3 of power plants supplying data centers are also ocated in water-stressed regions
    Still entirely a question of regulating externalities.
    Not all power generation requires significant water use. Your government is free to e.g. require new data centre capacity to be accompanied by an according buildup of generating capacity with according restrictions on water use.
    If that means data centres moves elsewhere, then so be it. That is part of the goal if you argue for pricing in and regulating externalities:
    Ensure that the cost of operating in a way that doesn't negatively impact the community is priced in so that decisions are taken based on the actual full cost to society.
    So to go full loop to my original comment (sorry): It's entirely a question of whether or not you want to allow it.
    This is what governments are for.
    n4r9 · 1790860007 · focus · HN ↗
    The government obviously has the power to regulate data centers. That's why people are petitioning them to do so, and why the lack of data transparency is frustrating. I'm not sure what argument you're making.
    vidarh · 1790935662 · focus · HN ↗
    The point I made was that the water use is not a property of building a data centre, but of building a data centre without regulating water use. As such there are plenty of data centres that don't use much water.
    That matters when considering what to regulate. A lot of people pushing for regulation are pushing for blocking data centres instead of regulating the externalities they claim is their issue.
    n4r9 · 1790938011 · focus · HN ↗
    I disagree. There is community opposition against individual data centers. There are calls for moratoriums until rules and regulations are improved. Calls for outright blocking data centers even with improved regulations are a small minority in my experience.
    RHSeeger · 1790779457 · focus · HN ↗
    You say that, but over and over we see things like
    > You can't build an apartment complex here, because our water/sewer system is already over capacity
    /ignores that statement and builds the apartment complex because "omg, we need more housing" arguments are used to not pay attention to consequences
    /water and sewer system can't keep up and all kinds of expensive problems occur
    troyvit · 1790780296 · focus · HN ↗
    > If a new project is causing a “strain on resources” then the utility planners have failed that community.
    Call it an echo chamber but when it comes to data centers that's the preponderance of news that I read. These two stories are about the county next door to mine. The first story highlights how the builders of the data-center continuously broke zoning laws. The second story from a month later describes how the board of commissioners let all that slide and approved construction to continue.
    <a href="https://www.cpr.org/2026/08/07/weld-county-ai-data-center/" rel="nofollow">https://www.cpr.org/2026/08/07/weld-county-ai-data-center/ <a href="https://www.cpr.org/2026/09/10/weld-county-officials-approve-data-center/" rel="nofollow">https://www.cpr.org/2026/09/10/weld-county-officials-approve...
    But it's not just my state:
    <a href="https://www.theguardian.com/environment/2026/sep/25/new-jersey-fines-datacenter-unpermitted-generators" rel="nofollow">https://www.theguardian.com/environment/2026/sep/25/new-jers...
    Those guys were fined a "record" $1.1 million, and:
    > The state is mandating DataOne apply for and obtain the required permits or cease operations, but is giving the company 45 days to do so, according to a NJDEP spokesperson. During that time, regulators are allowing the facility to continue running the generators.
    That fine is a slap in the wrist.
    tzs · 1790794357 · focus · HN ↗
    We're talking about an order of magnitude increase in the number of data centers in less than a decade and way more than an order of magnitude increase in the power needs because the AI data centers use a lot more power than even the big data centers of several years ago.
    That's way beyond what utility planners can reasonably plan for.
  6. quickthrowman · 1790786973 · focus · HN ↗
    If a water system doesn’t have capacity for a data center, they shouldn’t connect the data center to the water system.
    When you apply for a connection to a utility, they make you tell them your potential usage so they can assess if they can even connect you.
  7. brnt · 1790789170 · focus · HN ↗
    The Netherlands does not have areas sufficiently far removed from urban areas for this to matter. In fact the entire country has a managed water table, the bodies which govern it are the oldest demicratic institutions in the world (over a millenium), and survived any change in ruler country and government in the meantime.
    There's no river or creek not used for drinkwater consumption or management, and they are all connected to agricultural use and transportation (canal water levels) as well. It's one big system, and farmers cheating on how much they pump up is already too big of a proboem for this to not matter.
  8. AngryData · 1790797581 · focus · HN ↗
    In my part of the US there is enough rain that no extra water is used to grow alfalfa. The only water usage from beef production here is what the cows themselves drink.
  9. throwaway2037 · 1790805024 · focus · HN ↗
    > Data centers tend to concentrate their water usage within urban areas
    Ahh, what? The world's greatest concentration of data centers is in the suburbs surrounding Washington, D.C., USA. Almost none of that would be classified as urban. I offer a counterpoint: The vast majority of data centers are suburban, rather than rural or urban.
    > Their water consumption scales up around tenfold if you consider the indirect usage from generating the electricity.
    This is bullshit. I already disproved this myth here: <a href="https://news.ycombinator.com/item?id=49119054">https://news.ycombinator.com/item?id=49119054
    In short, "More than 90% of this is returned to source."

Open on Hacker News to reply ↗

Unofficial Hacker News client; not affiliated with Y Combinator.