Stupid question: datacenters need water for cooling right? But they don't boil that water, ie it comes out of the datacenter just a little warmer? If that is the case does it matter to the city? The warmer water can still be used for agriculture or any other common usage.
There are multiple ways. Closed loops, well not big deal you fill up and there is slight evaporation losses, but you could ship that in in tanker truck maybe once every few years.
Next is open loop cooling using secondary loop. Take a river, lake or sea. Pump some water from it, pass through heat exchanger and pump back out. Manageable for most of the year. Worse version is pump ground water and return it to these. Depletes the ground water...
And finally evaporative cooling. Which is boiling, but not at boiling point. Water goes to sky. No immediate return to local ground water or downstream the river... In this case you actually do in sense use up the water. Kinda like burning fossil fuels returns co2 to atmosphere. It will later turn to biomass, but that is a separate cycle.
The CO2 cycle is problematic because of timelines. We are releasing millions of years of CO2 accumulation.
Rain is more of a location problem. The evaporated water returns as rain quickly, but maybe somewhere else, such as over ocean. And the aquifer compresses and loses water retention ability.
It's not a stupid question but: technically, after passing through Google's facility that is now gray water, and you can't use that for agriculture or any other 'common usage' without a whole raft of work and you can't just dump it into the aquifer either.
But if it just went through some heat exchangers, it's not like if it was dirty? As far as I know, nuclear power plants return the water they consume to the rivers they extracted it from.
Heat exchangers could easily contaminate the water. If they're not kept hot enough they could be breeding ground for Legionella and a whole raft of other bacteria. Clean water is science, not just a matter of bulk pumping stuff from one place to another (though that's definitely a part of it). Water treatment plants are complex and have a ton of QA on their product. You can't just run it into a factory and pretend it is the same stuff going in modulo some increase in temperature.
But you are talking about drinking water. I would be surprised if they even use that for cooling. But any non human consumption use of water (like agriculture) should happily use that water, shouldn't it?
No, agriculture has fairly strict standards about the quality of the water, they can't use gray water to irrigate. Of course it will still work but depending on where you live the produce may then no longer be fit for human consumption.
You can use it for irrigating your lawn but not for vegetables, especially not if you plan on selling them. But 'light' gray water requires relatively little treatment before you can use it again, however this could still be quite expensive compared to just letting it go. I wonder if they've done any quantitative research on this that's public.
That's very interesting, thanks! I had no idea that legionella risk was a thing for data centers. This article mentions that to avoid the risk most data centers treat the water with disinfectants which are sometimes toxic:
They're really nasty bacteria and once in a system they are hard to get rid of because then you have to heat everything to temperatures that the system normally might never reach.
That's why central heating systems that run 'low' every now and then stoke up to 60 degrees or more on the secondary circuit for tap water.
And data centers are the perfect location, endless 35 to 45 degree water. Cooling towers are the main problem for this, another is aerosols of water that has been sitting in the sun for a while, for instance in a garden hose exposed to the sun.
This is America. Our toilets use _clean potable water_ to flush our shit.
Drinking water from the mains is metered, so it is observable from the business perspective. Life finds a way. Heat exchangers and datacenter plumbing absolutely breed life and put things into the water that were not there when it was pumped in.
Imagine if a datacenter used a shady supplier of pipe that used, say, lead in their alloy. Do you want that datacenter grey water going into crops?
Do you think that water that the water that flows from kitchen sink and water that flushes in the toilet in normal house/apartment come from different pipes in any other place of the world?
The water from the lake isn't drinking water either, it is contaminated with all sort of stuff including dead animals and animals excrements. But it doesn't mean it is not suitable for agriculture.
Yes, but that does not mean it is now clean water. Anything could happen between the moment Google ingests it and spits it back out, the assumption that it is 'just' a little warmer is nice but it misses the option of for instance contamination from a secondary circuit or various substances leaching into the water used as a coolant.
It’s gray water, and just as how I can’t dump gray water from my RV camper into the river, neither can a data center. After running through a heat exchanger there can be all kinds of crap in that water.
Data centers and power plants can and do return cooling water from a river back to the same river but warmer. What do you think is inside their heat exchangers but metal and water?
What do you think is inside their heat exchangers but metal and water?
It's a bad idea to drink hot water from the tap because of the concentration of metals that accumulate in the water heater. Don't assume that a little metal in your water is perfectly safe. As for agriculture, now the metals can concentrate in your lettuce.
And, as other commenters have pointed out, what else is in there? How about Legionnaires Disease?
How is that different from the metal pipes through which drinking water goes through to reach your kitchen tap, some of which are over 100 years old if you live in the UK? The contact with metal shouldn't be the problem in itself. Legionnaires disease either, the water from the river isn't drinking water to start with and the water out of the datacenter wouldn't be drinking water either.
When you start of with 'a stupid question' and people then give you lots of reasonable answers and you persist with more such questions at some point you cause me to doubt if you were really asking your first question in good faith.
I apologize for not humbly submitting to the first comment on HN. If I gave the impression that you were not the ultimate authority on this topic, I certainly did not intend to do so. I should know better than to oppose common sense on a topic that is way over my head.
I'm definitely not the ultimate authority on this subject or any other but you are either interested and want to know about this or you can keep putting up objections that are masked as questions which seems to be what you are doing.
The main reason we are talking about this is because 'environmentalists' (which in itself gives a hint about the levels of expertise) are worried, they are not worried for no reason. Listing a multitude of reasons should at least make you pause about whether or not they are sincere in their concern.
The degree to which industry would wreck the environment if we let it is by now very well documented. But the EPA has been gutted and lots of safeguards have been abandoned in the name of 'progress'. This is not without risk and I am very happy that in spite of all this a lot of people are still willing to speak up and to make sure that at least the worst excesses are curbed.
You can approach this with curiosity to try to learn about the subject and to try to understand what drives the worry of people that have studied this stuff for a long time. These are not just idle musings. Or you can put up a barrage of questions effectively casting doubt on anything that might be of concern.
The problem with environmentalists is that it is full of militants that aren't engineers and have very strong opinions that don't pass the most cursory smell test.
I am all open to there being problems with re-using water used to cool datacenters (hence my question). But 1) "it boils" defies common sense, no component in a computer should run at >100 degree celcius continuously, so I find it hard to believe that datacentres boil water (and I would have noticed the big cooling tower on the side of them). 2) Legionnaire disease is certainly a big deal in residential buildings with stagnant warm water, sitting in pipes sometimes for days until someone takes a shower. I fail to see how it is a major issue for a continuously flowing industrial application where the water spends very little time at elevated temperature and is continuously flowing before being released into colder water. 3) "contact with metal is bad" certainly doesn't come from someone who has seen the water supply chain in the UK or any European country with ancient infrastructures. Many of which are still made of lead. 4) "water is then not suitable for human consumption", well neither is the water in a lake. All drinking water has been filtered and sterilised. I would be surprised water used for cooling has been treated that way. So unclear to me why there would be any expectation that the water coming out of a datacenter should be any cleaner than the water coming out of a lake.
Now there is common sense, and there are regulations. The two often form a perfectly disjoint venn diagram. So I am happy to believe that there are regulations resulting in absurd situations. But from an actual risk point of view, I don't see how a datacenter "consumes" water, in any comparable way than a swimming pool, agriculture, chemical plants, or gardening, where the water cannot be used for anything else after that. To me it is more akin to a nuclear power plant, which releases water at a slightly higher temperature (despite actually boiling it), and therefore has a fairly limited impact on the water supply.
> it comes out of the datacenter just a little warmer
Exact values matter. Some power plants had been found dumping +10 C water into lakes/rivers, while they had permit only for +5, and it totally destroyed local ecosystem. And most efficient (in terms of money) is evaporation cooling, where at least part of water is "lost".
A lot of it gets converted to water vapor in the evaporative coolers, so it doesn't flow out -- it becomes humidity or clouds. The coolers do also produce waste water, but with all the minerals left behind after evaporation it's not suitable for drinking.
