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Cheaper Energy From Caverns of Compressed Air
An anonymous reader writes "By using the Earth's vast underground caverns to store compressed air generated by wind farms at night, several U.S. municipalities will be 'going green' by using that stored energy to generate daytime electricity on the cheap. Engineers at a National Lab think compressed air stored in underground caverns could cut in half the cost of electricity."
Earth's vast underground caverns? Oh please. If scientists actually tried doing this, it would surely bring about the end of life as we know it. The atmosphere would all be sucked up into these vast caverns leaving nothing but a vast vacuum on the surface. No, thank you!
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How far are the turbines from the caves? What happens if the wind that should be generating electricity for the compressors takes the day off and chooses to make an unfashionably late arrival? How much of a boost do the turbines get from the compressed air?
I'd think with enough losses along the way (steps up/down in voltage at transformers to transmit the power to the compressors, mechanical inefficiencies of the compressors, dependence of the turbines' optimum performance on this assistance) the project, while novel, could take a while to pay for itself. I'm not suggesting that bleeding-edge science should be economically feasible - that should come after the science is established - but that efficiency should be priority number one so that the technology can become competitive with other ways to store potential energy.
I'll be your candy shop of infinite deliciousity if you'll be my discotheque of endless rump-shaking.
I'd think geothermal or tidal power generation would be much better personally, harnessing an easily recyclable process seems like a much better idea. I've often wondered if the pressure of the ocean at extreme depths could make mechanical generational of power viable using simply the pressure of the ocean itself.
Underground caverns where newfangled energy producing technology has been introduced might not be the optimum place to own real estate.
I think those guys are full of vast hot air.
For me, it is far better to grasp the Universe as it really is than to persist in delusion
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Yeah well if you stand out in the sun for 10 seconds in black clothes, you get hot. It doesn't get much easier than that. Why drill into the earth when we're being bombarded by unbelievable amount of solar energy right here on the surface. If I was president, almost all funding would go to developing solar hydraulic towers and more effective solar panels. Plus, compressed air runs out. The sun won't for quite a while.
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...for that new movie with Brendan Fraser and the dinosaurs?
This has been done on large scales by a couple of power plants in the past.
http://en.wikipedia.org/wiki/Compressed_air_energy_storage
In Xanadu did Kubla Khan
a stately pleasure dome decree
where Aleph, the sacred river ran
down to caverns measureless to man...
from memory, apologies to Coleridge
Those words were famously written after an opium-induced hallucination, as was this plan
my insights may be modded Funny, but at least some of my jokes are modded Insightful
Yeah, I keep a lot of compressed air in my cavern. It's so powerful that sometimes I can't contain it any longer and it escapes. /ducks
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It is the rest of us that have to duck, not you.
I can just imagine some poor hiker being blasted into the sky walking or climbing over one of these pressurized caverns, just because the engineers had missed a hole somewhere inside the main cavern.
It'd be ideal if they could spray some kind of airtight lining along the walls, but that wouldn't be too eco-friendly, would it?
"If a nation expects to be ignorant and free in a state of civilization, it expects what never was and never will be."
Caverns of Compressed Air
Earth is farting?
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Maybe I didn't understand the article well enough, but it just seems to me like they're using energy to compress air in caverns during the night, then using that air to make energy production during the day more efficient. Unless they're violating thermodynamics here, the amount of energy gained by using this compressed air system can't be more than the amount of energy used to compress this air into the caverns.
So, is it that only benefit here, cheaper energy costs, comes about because they're buying the energy when it's cheaper, and storing it for use when paying for this energy is more expensive?
Interesting idea, but IMHO, these will be obsolete fairly soon. Plug-in hybrid cars are right around the corner, and they're going to use up a lot of off-peak power - I think. I've never seen the math, but I imagine that moving a car 20 miles on batteries is equivalent to a whole lot of light bulbs, computers, and TV hours. That's the exact same target power that compressed air, and gravity storage (i.e. pump water uphill) are meant to store for peak time. Also, solar power, the other power plant of the future doesn't work very well at night. So, for the overall grid, the peak aren't going to be as dramatic.
You've deflated the Earth!!!
I don't really know much about earth or soil sciences, but just off the top of my head, would this not cause destabilization in the ground above the surface of these caverns? I'm just thinking about things like cave-ins and whatnot.
Production ... used up all the easily available vacuum on earth (mined from the air which contained precious little vacuum! - bringing it down from space is not cost-effective!)
Oh, come off it. There are still plenty of untapped vacuum sources around.
There's about of cubic foot of the stuff in any PHB cranium, you just need to open the thing and tap it! Granted, you'd need quite a bit of source PHB, but that's easy enough to come by -- and it's renewable.
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As gas expands, it cools. Assuming the compressed gas has enough time to cool considerably before it's released again, couldn't this also be used like a reverse long-distance heating to save more energy during summer months?
The grass is always greener on the other side of the light cone.
Why not just put carbon dioxide down there, and burn more coal?
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Wind puffs during night turn the turbines, which compress air and store it underground. The stored air can then turn the turbines to regenerate the night puffs during the day, when people are awake and can appreciate them! Profit!
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..that thrive in these caverns? Who knows what kind of impact it would have on the earth as a whole if we eliminate dozens/hundreds of subterranian life forms with this plan.
This could possibly be the most short-sighted plan yet.
will it still be after you compress the air?
One of our competitors trademarked the term "hypothesis". From now on, we will call them "boneheaded ideas".
Without having read TFA, I imagined they were simply using the compressed air to power a generator... sort of like putting a pinwheel in front of the nozzle from a balloon. Which wouldn't have been so much more efficient, really.
It's more interesting than that, though. They're using the compressed air as the input to (natural gas)-powered turbines, saving on the energy that would have been used to run the compressors.
I'm still not sure where the energy savings comes in, though. The article says "uses fuel more efficiently"... but then why not treat the fuel that way ALL the time? Because you don't have the "excess" compressed air? But you're using power (the night-time wind generation) to create that excess.
The only case I can see where this actually buys you anything is if your wind generation at night is also in excess of your needs at night. I'll grant you "generation minimums" (below which the cost of restarting the gas/coal/whatever generators becomes an issue), which might help the wind power be "an excess".
My instantaneous reaction is . . . Caverns Leak . . .
We are Dead Stars looking back Up at the Sky
The problem being addresses is the intermittent nature some renewable power sources (e.g., wind & solar). In some cases the delivery curve from some sources will match your demand curve and then you have a win. Of course sometimes it does not match the demand curve so you have three options: 1) add more distributed capacity to handle any peak needs so that even if one hears has clouds or no wind the rest make up for that (very high capital cost), 2) create a storage medium such as pumped water, compressed air, chemical batteries, or in the case of thermal solar thermal storage (heat up a really big tank of sodium metal) - it is all a matter of creating "capacitance" in the system, 3) The best way to manage a non-ideal supply curve is to alter your demand curve. There are many big energy user such as ice plants, chemical plants, water pumping, and other industrial plants that can be interrupted on short notice or be scheduled to change the shape of the demand curve. Also, expect to start seeing appliance that will get cues from the utility company to postpone their demand until power is cheaper.
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This doesn't seem like a good thing for all the critters living in those caverns.
Why do I have to smack the Preview and Submit buttons about ten times each before slashdot finally takes the post now?
Newton's Laws and the Laws of Thermodynamics and whatnot. What are the long-term effects of all these?
Using tidal energy will give us lower tides.
Use enough solar power and the Earth gets less heat.
Use enough wind and weather patterns change.
Energy and matter are both finite, and every system favors entropy.
Seems to me we can't really escape it and every option has the potential to adversely affect the entire planet, whether people acknowledge it or not.
Anyone who says otherwise is selling something...
"People are stupid; given proper motivation, almost anyone will believe almost anything."
A similar system is used quite frequently today where water is pumped uphill into a reservoir at night, and then run through a hydro-electric plant during the day.
It isn't just that electricity costs more during the day though. With a traditional (coal or nuclear) power plant, it is less energy efficient to run at reduced capacity compared to running at full capacity (I think it has to do with the pressure in the steam chambers). You also waste a fair bit of energy to starting and stopping a plant. However, hydro-electric generators don't have as big of a problem with this.
So even with the energy losses incurred by changing state twice, it actually ends up being more energy efficient to keep the plant running at ideal capacity at all times and using the pump storage to balance the load than it does to try and balance the load with the coal plant itself.
With wind power it makes even more sense - the wind blows when it wants to, and if it's at night when people aren't using the energy you either let it go to waste or find some way to store it.
When you look back at it, it is hard to believe that the people in the 1900s were so short sighted and selfish; leaving their children and grandchildren with a vacuum deficiency. Luckily out generation if far more thoughtful and won't mess up the planet for our kids!
Engineering is the art of compromise.