Meh. The biggest data center (ChinaTel's Inner Mongolia Information Park) consumes about 150MWe, assuming all of it becomes waste heat it's basically nothing: a nuclear reactor (each plant has 2~8) releases 2Wt for each We it produces, and they're usually sized between 800 and 1300MWe.
Hell, earth averages 160W/m^2 from the sun, oceans cover 360m km^2, so oceans get 10^16 watts from the sun.
Not to say that it can't have a significant local effect, nuclear plants are strongly regulated to avoid heating their rivers too much (especially in warm summers), and again we're dealing with orders of magnitude more heat dumping heat waste in a very finite (though moving) amount of water.
"Experimental underwater data centres could be more sustainable if connected to offshore wind power, but Microsoft must focus more on investing in new renewable energy now. [...]"
Seems a shame to let all that heat go to waste. Surely we put that waste heat to use and a distillery or desalinization plant or something.
So combination data center, desalinization plant, and pickle factory then?
This gif: https://www.ucsusa.org/sites/default/files/images/2015/08/np... shows how typical nuclear reactors work. They're functionally just steam turbines, the nuclear power is just capable of heating a whole lot of water.
The waste heat, though, doesn't come in contact with the radioactive parts. That's what's happened on the bottom with the condenser.
My prediction is we'll be amazed at the life forms that develop and explode around such submerged cooling structures.
Ocean warming is extremely detrimental to ecosystems across the globe. You can't just simplify it to more heat == more energy == better
>In other non-tropical regions of the world, marine heat waves have been responsible for widespread loss of habitat-forming species, their distribution and the structure of their communities. This has a tremendous economic impact on seafood industries that have to deal with the decline of essential fishery species.
>It is likely that over the past century, the impacts on ecological chains have been more frequent as ocean temperatures have escalated decade after decade. This is the case in Nova Scotia, where kelp forests are literally being wiped-out by water which is much warmer than usual. In this corner of Canada, the ocean is not just a form of recreation, it also means a way of life for many that rely on fisheries and aquaculture as an important part of their economy.[1]
[1]https://www.theweathernetwork.com/news/articles/ocean-heat-w...
That's cute, but 1. nature will adapt just fine to both heat and cold so that's not exactly compelling; 2. the issue is we may not, human civilisations have arisen in fairly specific conditions, and tend not to be very resilient to significant environmental changes
> My prediction is we'll be amazed at the life forms that develop and explode around such submerged cooling structures.
My prediction is we won't live long enough to see that happen, it takes kilo- to mega-years for anything more complex than bacterial mats to evolve to use new sources of anything.
Not with the same ease! That's the point — it is a one-way street. "Having easy access to energy" or "not having easy access to energy" are NOT equivalent states for flourishment. They're not equally "just fine".
The rest seems like you're grinding some anthropomorphic axe unrelated to my post, so I'll abstain.
Life needs an energy gradient. In this case, direct access to colder water. No organism (or machine) can use the heat energy of its environment if it has no access to a colder medium.
Edit: I just saw that Retric explained it better (https://news.ycombinator.com/item?id=17245948).
It looks like my original comment hit some HN ideological hot spot (unintentionally), but it's entirely uncontroversial scientifically.
If a fish is swimming in 24°C water, it can't simultaneously be swimming in 19°C water. Maybe its friend 10 meters away is swimming in 19°C water, but that doesn't help the first fish.
Maybe that fish feels more comfortable in 24°C water, because it needs a certain body temperature to keep its internal processes running (i.e., to not freeze to death), but it cannot harvest energy from the 24°C water, which is what you claimed above. I'm not nitpicking, this is one of the most fundamental and important laws of physics.
This is probably more relevant at temperature gradients greater than 5C, but it's thermodynamically possible.
In this context, we're not worried about the literal definition of natural but about keeping an environment in a state in which humanity can survive.
https://en.m.wikipedia.org/wiki/Second_law_of_thermodynamics
Life wants entropy like sunlight or glucose becase it can do something with it. Heat can speed up chemical reactions which makes a minimal amount useful indirectly but not as an energy source.
PS: Heat gradients are a form of entropy and for example create thermals which are then useful.
I was actually pondering whether to expand on "energy", "water", "carbon" and "life" in the original post (none of them trivial concepts) but decided against it. It'd only muddy the waters, so to speak, missing the point:
A submerged data centre will be a net boon to the biological life around it.
Why would that be the case? If this were the case, the biological density of the highest-temperature locations in the ocean should be significantly higher than average. This has not been observed. Quite the opposite, actually.
Secondly, in thermodynamic terms, heat is the least useful form of energy. Heat is often the waste product of a chemical/mechanical process and cannot be easily be converted into other forms of energy without significant loss.
And no offense, but water and carbon are both trivial well defined concepts. Energy is also fairly well defined.
I agree making use of subtle energy gradients is not trivial, but life is pretty good at it nevertheless. Even in conditions you wouldn't expect it. And no surprise — it had billions of years to evolve that way.
If you wanted to be daring, you could even say that's what life is for.
That's absolutely not what the comment you're replying to says. What it says is:
> If this were the case, the biological density of the highest-temperature locations in the ocean should be significantly higher than average.
> Thermals mentioned by OP are just one obvious example.
Thermals are not just heat, and by and large the heat is not a source of energy (sulphur chemistry is the basal energy source of thermals). And shallow waters have much higher biological densities.
Ambient heat is only useful so far as helping the organism improve the efficiency of its chemical and biological reactions, it's extremely rare for it to be an actual energy source (because as you've been told multiple times it's extremely hard to use/harvest). And organisms are generally adapted to a certain level of ambient heat with compensatory mechanisms matching, most don't do very well if you drastically change their ambient heat levels, again aside from micro-organisms with short lifecycle which can adapt extremely quickly.
You disagree, giving reasons I find irrelevant here (a data centre won't make a dent in the average ocean temperature, and certainly won't make it "the highest-temperature location in the ocean"), but I respect that. The good news is that the impact will be easy to evaluate once deployed.
In fact, testing the data centre's impact on the surrounding ecosystem will surely be a mandatory component of any such project, so we'll get to see the hard data. Let evidence be the judge of the "absolutely nots".
Is it to steadfastly argue positions far outside your domain expertise or engage in discourse and learn?
Of course you could argue that the lower cost of this cooling method will create a larger demand for cheaper servers/data storage, which increases net harm, for which I have no answer.
That argument doensn't apply here: demand isn't currently being constrained by us being affraid of the environmental impact of datacenters.
Conversely, if it became literally free to operate, you can imagine we'd have a higher demand for data, storage, etc.
It's like how center pivot irrigation reduced the water usage rate per acre but increased demand for water usage in various areas because costs were lowered as well.
That's not the case if you're comparing with AC. You have to use energy (generating more waste heat) to pump heat up a temperature gradient.
Find a desert under the sea and drop them all there. Some place that's basically water and dirt. It's probably going to be large enough that you could dump all of humanity's data centers there for the next 100 years and still have room to spare.
It's rather easy to calculate because one calorie is the energy required to heat up one gramme of water by one degree Celsius, the rest is just unit conversions, but I could have messed up anywhere of course.
Even if I'm off by a few orders of magnitude I'm confident that datacenters won't be noticeably heating up the sea for a long time.
I'm not saying there is a problem with your calculations, but if you were just one order of magnitude off, then after 10 years that would be 1°C, which is a colossal amount. The main problem with global warming, as I understand it, is that 1 or 2 degrees change to the atmosphere would melt a huge amount of polar ice. I imagine that if the sea were increase in temperature by that amount, given that water has better thermal conductivity than air and that's kinda where the polar ice mostly is, the effects would be at least as bad (?)
Edit: given that some of the heat would dissipate into the atmosphere and sea bed, maybe it would need to be more than one order of magnitude higher to have this effect.
That is assuming that all the electricity produced on Earth is used to heat the oceans, which is not realistic. Oceanic datacenters are not likely to ever amount to more than a few percent (and even that is unlikely) of the total human electric consumption.
For reference, apparently datacenters used 416 TWh in 2015, which is 0,002% of the total electricity usage.
That's why I'm confident that there is a lot of margin in my calculation.
Oops, I misread your comment, sorry. I thought you were talking about all electricity used in data centres worldwide.
or 1000 years if off in the other direction
$ units -t '24816400 GWh / (1347000000 km^3) / (1 kg/dm^3) / (4200 J/kg/K)'
1.5908368e-05 K $ units -t '24816400 GWh / (1347000000 km^3) / waterdensity / water_specificheat'
1.5851925e-05 K
Since that's the same order of magnitude as, say, a US household, that does seem credible.
You're not putting all of the planet's datacenters within 5km^3 either. The calculation is fine.
Your calculation is stupid because you dont need to heat up whole ocean, heating up small areas it will be butterfly effect, enough to badly affect bigger areas. Look at this:
>As the concentration of carbon dioxide in the atmosphere rises due to emissions of fossil fuels, more of the gas is dissolving in the ocean. That is lowering the pH of the water, or making it more acidic, which can make it harder for reef-building organisms to construct their hard skeletons.
Minor change in CO2 changed pH of water, which kills organism in wider area.
https://news.nationalgeographic.com/2016/03/160321-coral-ble...
There are also closed seas like Baltic that need over 100 years to fully mix sea water with ocean water, it's much less salty than other seas and warmer, also much more polluted from toxins that were sinked there during and after WW2.
No need to be rude. "There is an issue with your calculation because" would have worked :/
Then there's natural geothermal vents doing that, but probably an order of magnitude more, since before humans were around.
The ocean is a pretty big thermal mass.
Take the mediterranean for example, a relatively small ocean. It has a volume of 3.75e15m3, with a mass of 3.75e18kg.
We need 4kJ/kg/K to heat up water. To heat the whole mediterranean by 1K, we need an energy of 1.5e19kJ, or 4.16e6 TWh.
In 2008, total worldwide primary energy consumption was 1.32e5 TWh, 31x less energy than needed to heat the mediterranean by 1K.
I doubt it will become popular because it involves waterproofing the enclosures, complicates maintenance staff access, and also carries the risk of water getting in and damaging the equipment.
There are other alternatives to AC. Using a cooling tower is a much better alternative to submerging the whole datacenter.
>> "Microsoft's Ben Cutler insists the warming effect will be minimal - "the water just metres downstream would get a few thousandths of a degree warmer at most" - and the overall environmental impact of the Orkney data centre will be positive."
It's not like we've heard that before about carbon dioxide emissions and other environmental pollution. Companies have mostly a different interests than the protection of our environment, from past experience.
I'm very interested to see what scientists and researchers think of this.
This is more a lot more efficient.
Perhaps there might be a localised effect, but I doubt the effects would be as severe as the carbon emissions saved.
[1] https://en.m.wikipedia.org/wiki/Thermal_pollution
[2] https://www3.epa.gov/region1/npdes/merrimackstation/pdfs/ar/...
Makes as much sense as the people who think that windfarms will eventually stop the wind, or people who worry that smoking is contributing to global warming.
But since the goal is to cool the datacenter, we want the temperature difference to be as small as possible.
Reclaiming energy from waste heat usually only pays off in industrial settings. If you have very hot steam, you can use it to power a steam turbine and generate electricity. But at lower temperatures, the efficiency is too low.