Google flushes heat from data center with toilet water
arstechnica.com
arstechnica.com
I joke with folks who think running a datacenter is 'exciting' its like watching grass grow, except its dark and their is no grass. Maybe I should blog about this stuff, but at social events it seems impossible to maintain a conversation about apex cooling vs planar cooling vs directed airflow or conduction, or 208 three phase vs 120 single phase vs DC. Perhaps I go to the wrong types of parties :-)
sigh
From the outside, the datacenter is an inaccessible realm of high technology, carefully engineered to maximize various important features. From the inside, it's cabinets and wiring and plumbing.
http://degiorgi.math.hr/~vsego/phun/beautiful_supercomputer/
I look forward to the fun stories we'll hear when data centers save a power conversion step by boosting line voltage to around 300VDC (necessary for PFC), and then put say 25 servers in series (floating from ground).
To be fair, I expect it helps that after all that stuff is dealt with, the equipment turns all those watts and volts into waves of pounding bass and hordes of dancing people, as opposed to just pushing bits around.
BTW for anyone who does want to debate pro audio, head over to http://forum.speakerplans.com/
1) Some people don't know just how noisy a data centre can be.
2) Some people just like seeing a rack with a caption saying "48 TB across X drives in Raid Y"; or lots of cat 5 / 5e / 6.
3) Innovative solutions for heat, aural noise, electrical noise, power, security, bandwidth, etc.
Most people on HN aren't going to be in group 2. But there's so many smart people on HN, and I'm surprised that this stuff feels so (and I know this is the wrong word) "backwards". (Maybe "stagnant" is better?)
Energy has cost, and reducing that cost is a space for making money.
So it would be blasting full cold all day and all night, and we were miserably cold. Nothing like wearing three jackets to work in the middle of August in Maryland.
So one day, we brought in a few refrigerator boxes, attached them to the ceiling to make a make-shift vent, and then we shunted all the cool air to the "server" side of the room.
We were much happier after that.
Basically they're taking pre-treated water from the city sewage plant and running it through their own mini-treatment plant to a level that allows them to use it in their cooling system. They do mention filtration & sterilization from chlorine, so I am wondering really how much different the cooling water is compared to potable drinking water.
The water they're getting from the sewage treatment plant is definitely not raw toilet water. I imagine Google is getting a big discount by treating their own water.
Google must treat the water with chlorine, because of risks like Legionnaires' disease.
http://blogs.technet.com/b/msdatacenters/archive/2011/10/13/...
This area of the united states suffers from huge water shortages, and the river they are using is a major source of water for Atlanta (I'm not sure if they are upsteam or down from Atlanta).
As a result by the time the river flows out of Georgia into Alabama and Florida it is very diminished. This makes those states pretty upset since they also want to use the water.
So what does Google do? They evaporate the water! What a waste.
Water cooling is not really a very clean thing in this part of the country.
I would like to see some numbers: How much energy does it cost to desalinate the amount of water they are wasting? If it's more than the energy they are saving then they do not have a net win.
If Google cools with fossil fuels during only droughts, that is still much better than using fossil fuels all the time.
The two reservoirs which provide water for Atlanta are located far north of Douglas County (I'm a resident).
I do find it odd that they are using evaporation cooling, since humidity is so high here.
Quite literally a drop in the bucket. The back of my envelope has too much written on it at the moment, but if you look at the total water flow in that watershed and multiply it by the heat of vapoization of water you get a staggeringly large energy flow. There's no way; absolutely no way at all a few megawatts of server heating would be measurable at all. None.
However, I don't think they actually want to evaporate all that much water which leaves a lot of residue issues and instead focus on heating a much larger volume of water.
PS: The article is also wrong in that they don't directly cool hot air from their servers with this water. They are cooling air heated by there cooling system and depending on how hot the air from there servers are they may simply vent that if it's warmer than the outside air.
I see that Atlanta rainfall is about 48" (122cm) a year.
422 gallons * 24 * 365 (* 3.785 litres/gallon) * 100 cc/L == 1.4e9 cc/year.
So converting to rainfall area: 1.4e9cc/122cm = 1148 m^2
Basically a 100' square catch basin on the roof of the building would provide all the water they need. Noise.
Which raises the question: Why don't they just do that? I'd imagine it would be less effort to process, and even though you do need to have a buffer against low rainfall periods, water is one of the easiest things to store.
Google's total worldwide power usage is about 220 megawatts, calculate the amount of water starting at about 20 deg. C average needed to evaporate to carry away all that energy and that works out to about 700 million gallons of water needed per year. Which is about one or two days of water usage for Atlanta. Keep in mind that this is for all of google's data centers worldwide. For only the servers that are actually in Georgia the amount of water carried away is incredibly small compared to total usage.
Also I didn't account for radiative cooling which is probably fairly significant but likely not more than, say, 50% of the necessary cooling load.
i'm guessing google has a big datacenter PR disaster that they think is going to leak soon, or else Mr Kava is looking for a raise.
"Green Google" also is a halo for the company overall, and might be heading off negative press about how Google alone uses more electrical power than all the households in (several lightly populated states, chosen to mislead).