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Underground 'Wind Mines' Could Keep Datacenters Powered
Nerval's Lobster writes "Major IT vendors have been including custom-built wind- and solar-power farms in their datacenter construction plans. But while wind and solar power may be clean, they're often unreliable, especially by the standards of datacenters that need a way to keep operating through any unexpected surges or drops in power. How about saving the wind that generates the power? That might work, according to researchers at the federal Bonneville Power Administration (BPA), and U.S. Department of Energy's Pacific Northwest National Laboratory. A study published in February (PDF) outlined the potential benefit of pumping pressurized air into caverns deep underground as a way to store wind energy, then letting it out whenever demand spikes, or the wind drops, and the above-ground facilities need help spinning enough turbines to keep power levels steady. The technique, called Compressed Air Energy Storage (CAES) isn't new: existing CAES plants in Alabama and Huntorf, Germany (built in 1991 and 1978, respectively) store compressed air in underground salt caverns hollowed out by solution mining (pumping salt-saturated water out of concentrations of salt buried far underground and replacing it with fresh water). But implementing such a technique for datacenters might take a little work. The BPA and the Pacific Northwest National Laboratory have already identified, and are evaluating, sites in the Pacific Northwest that would be suitable for CAES underground reservoirs; the first, which could be located in Washington's Columbia Hills could—via existing CAES technology—store enough compressed air to generate a steady 207MW for 40 days of continuous usage, ultimately delivering 400 additional hours without adding any compressed air."
burritos. Then we have them run over to the turbines and release any stored energy. The department of energy calls it Flatulence Assisted Regeneration Technology. Doesn't work quite as well as pumping the earth's crust up like a baloon though.
This is power storage, not generation. Think of it as a big underground air tank. You pump air in to store power (when your wind farm is making more than you need), release it though some turbines when you need power later.
Wouldn't it take a buttload more power to move the air down, and then back up, than it would generate?
I think it presumes excess power during some periods. High winds, excess hydro power, what ever.
They do this at Grand Coulee Dam already by pumping water up-hill to an additional reservoir in periods of excess runoff when they would otherwise have to open the spillways just to get rid of the excess.
Pumping water uphill is probably far more efficient than compressing air.
Sig Battery depleted. Reverting to safe mode.
If you use an air-water mixture, this can be done quite efficiently: http://lightsailenergy.com/
Calling a chamber to store energy as pressurized air a "wind mine" is like calling the fuel tank in my car a "gasoline well".
207MW * 40 days =
207MW * 3456000 s =
715392000MJ =
7.15392*10^11J
This is roughly equivalent to 170 megatons of TNT. 1.7 times the size of the maximum theoretical yield of the Tsar Bomba.
Probably more than enough to start an earthquake in an area that is susceptible (such as the pacific northwest).
"Evil will always triumph over good, because good is dumb." - Dark Helmet (Spaceballs)
Quite many buttloads, I'd presume.
Fortunately a buttload of pressurized air doesn't actually have much force behind it.
Source: personal experience.
Does this rag smell like chloroform to you?
"Hey look, Bob, I found a new cave! All we have to do is move those rocks out of the way and..."
Table-ized A.I.
Wouldn't it take a buttload more power to move the air down, and then back up, than it would generate?
Any flavor of energy storage is going to introduce some sort of conversion losses: battery banks aren't 100% efficient to charge or discharge, flywheels suffer from friction losses, pumped-water hydro suffers from inefficiency in the pumping uphill and the conversion to electricity downhill backup generators suffer from the fact that small heat engines generally get lousy efficiency compared to big ones(and need to be kept supplied with diesel, which doesn't help you 'green' cred).
The advantage to pressurised air is that(in geologically suitable locations) you can build in fairly large amounts of storage without anything obtrusive on the surface, and at comparatively low cost(compared to buying and keeping fresh huge banks of batteries, say).
The Bath County Pumped Storage Station in Virginia is a pumped storage hydroelectric power plant with a generation capacity of 3,003 MW:
Water is released from the upper reservoir during periods of high demand and is used to generate electricity. What makes this different from other hydroelectric dams is that during times of low demand, power is taken from coal, nuclear, and other power plants and is used to pump water from the lower to the upper reservoir. Although this plant uses more power than it generates, it allows these other plants to operate at close to peak efficiency for an overall cost savings.
It must have been something you assimilated. . . .
sure. not to mention the atrocious efficiency of wind power. Just pump water to a reservoir instead and let it out when you need it.
I think that the article is trying to be clever, but missing an important point in doing so. Energy is generated from the compressed air using a more conventional turbine/generator setup... not a wind farm. This system is just an ENORMOUS UPS.
Nah it goes down due to gravity see...
Seriously though, energy efficiency is not the problem when you are producing far more energy than demand. As long as it makes sense and pays the cost/maintenance on the pumps/storage site, it's a workable idea.
Seven puppies were harmed during the making of this post.
Using compressed air as a storage medium has a number of problems:
1) Low energy density. Air is very compressible. While that's what makes it usable as power storage in the first place, the amount of energy that can be saved in a gallon-sized container as compressed air pales next to a gallon of gasoline.
2) Power loss through thermal contraction.. When you compress air, it heats up. As that heat energy escapes, it effectively takes away a good chunk of the energy you consumed compressing it in the first place. Once the compressed air has cooled, the effective pressure drops. The more air you compress into the same space (See Energy Density above) the worse this effect is.
3) Power loss through leakage Even when available, caves are terrible places to store compressed air. Even if you seal the cave somehow, you then have to deal with seismic shifting, creating leaks and causing your beautiful, N-redundant power source to leak into an underwater stream bed. Lastly, even when sealed properly, air will *still* leak out. Ever wonder why your bike/car tires need to be aired up every so often even when they *aren't leaking?
Air molecules are wily little critters
4) turbine inefficiency The higher the pressure of compressed air, the more the above problems manifest themselves. However, the lower the pressure of compressed air, the less efficient it is to convert the compressed air back to electricity!
Good solutions address the multiple facets of the problem. For example, much of the cost of running a data center is spent on cooling. It might be preferable to store "coolth" in a stone or liquid cooling chamber under the facility than to try to store compressed air. Compressed air can be turned into electricity, which is more flexible, but is also more lossy for the reasons listed above. A combination of technologies will be needed to provide the best answer for redundancy and efficiency.
I have no problem with your religion until you decide it's reason to deprive others of the truth.
If the (wind|water|nuke) energy is just going to go unharvested/unused due to low demand during high or peak production, it's much less of an issue.
If you lose 20% of something that you were throwing away anyway, you're still ahead of the game.
I did see they are trying out (or by now using) heat exchangers to help lessen the thermodynamic losses, storing the heat as well as the air.
One plan even used some natural gas heaters during the generation phase.
Won't this inevitably lead to a situation where we are forced to purchase wind-generated energy just to get the wind farmers to release enough breathable air for humanity to survive? I, for one, say "no thank you" to eternal debt slavery to the alternative energy consortium.
another example:
http://en.wikipedia.org/wiki/Salina_Pumped_Storage_Project
I believe this is where Google has a datacenter that consumes hydroelectric power.
...So you're telling me, they've invented a way to store wind in caves, and they called the acronym CAES?
Come on guys, figure out something to slap a V in there.
Where's the water going to go?
So just to be clear, you don't care about salmon? Because to me, they are very tasty, and I want them to not be extinct because then I cannot eat them.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
I was thinking the same thing but then I realized nobody ever includes the cost and efficiencies of actually making giant storage batteries. So I suppose if you live next to a salt mine and have plenty of wind, it might be worth it.
They're going to be injecting the air into deep reservoirs that are already pretty hot to start with. Somewhere in the paper it stated that the temperature went as high as 175C in the basalt basin.
Except the warm surface air you pumped down underground will cool, PV==nRT resulting in less volume and less pressure, so while the air may be under great pressure when you send it down however it will loose pressure and there for potential energy over time.
entropy is a bitch.
---Saying gnome 3 is better than windows 8 not so much a compliment as it is damning with light praise.
Err...all that means is that you pump in more surface air until you achieve the desired pressure in the cavern. I don't think they are talking about using existing pressurized air...they are talking about utilizing large pumps to continually fill the underground reservoir until a desired pressure is acheived, after which it is kept constant by adding more air as needed.
Ultimately I can even see the expulsion of the air in the reservoir passing through heat collection systems in the datacenter to cause expansion of the compressed, cooled air as it is exhausted, thereby creating even more pressure. This would serve the dual purpose of heat reduction in the facility and more potential energy from the usage of the now heated pressurized air. Hell you could even just pass the air through a pressurized pipe maze that runs across the ground's surface or the facility's roof and allows the sun to heat the air as it is released. Obviously this would not work as well at night but through a combination of techniques, additional pressure could be created to eke every last bit of energy out of the compressed air.
Using some engineering, PV==nRT can be made to work for you instead of against you.
The lost GDP in Salmon exports outweighs the Power exports in Washington State: Grand Coulee's primarily provides power to the US Government facilities, not anyone in Washington State. It also provides power to Arizona. People buy power from Bonneville Power in Washington State. The return of proper salmon runs will currently add > $4 Billion in GDP.