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The Future of Wind Power May Be Underground

samzenpus posted more than 4 years ago | from the blow-from-down-below dept.

Earth 223

Hugh Pickens writes "When the wind is blowing, it is usually the cheapest peaking power available. However utilities need consistent always-on power from large, cheap coal and nuclear power plants that are the backbone of the electric grid. Wired reports that operators are looking at Compressed Air Energy Storage (CAES) using abandoned mines and sandstones of the Midwest to store compressed-air. This converts the intermittent motions of the air into a steady power source by using it to run air compressors to pump air into an underground cave where it's stored under pressure. The first CAES plant in the United States actually went online in McIntosh, Alabama in 1991 where engineers created a geological pocket 900 feet long and up to 238 feet wide in a dome by pumping water into it to dissolve the rock salt. When the (briny) water was pumped back out, the salt resealed itself and they had an air-tight container."

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223 comments

Generate a Vacuum (5, Interesting)

rally2xs (1093023) | more than 4 years ago | (#31435218)

Instead, build long tunnels between major cities, evacuate them down to between 0 and 3 psi, and run high speed trains through them. The trains would need very little energy to run thru the extremely thin atmosphere, and the pressure diffential can be used to generate electricity when needed. 2 birds, 1 stone.

Re:Generate a Vacuum (2, Insightful)

Black Gold Alchemist (1747136) | more than 4 years ago | (#31435232)

It would also transmit the electricity. 3 birds, 1 stone.

Re:Generate a Vacuum (0)

Anonymous Coward | more than 4 years ago | (#31435252)

Alien life forms couldn't pass the evacuated tunnels. 4 birds, 1 stone.

Re:Generate a Vacuum (1)

Statecraftsman (718862) | more than 4 years ago | (#31435278)

This would also employ like 1 milllion people so...yeah. 5 birds.

Re:Generate a Vacuum (4, Funny)

Patrik_AKA_RedX (624423) | more than 4 years ago | (#31435310)

We could use those stones to build houses for the poor. So, ... Six stones?

Re:Generate a Vacuum (0)

Anonymous Coward | more than 4 years ago | (#31435628)

We can gain wait sitting in our basement thinking up futuristic ideas for Slashdot posts. So, ... er, 16 stone?

Re:Generate a Vacuum (5, Insightful)

Avin22 (1438931) | more than 4 years ago | (#31435318)

2 birds, 1 very expensive stone. It would probably cost a great deal of money to build tunnels, evacuate out almost all the air, and maintain that low atmosphere. Sure, it might save some energy of running the train, but the money and resources needed to do this would greatly outweigh any benefit. We are almost certainly much better off investing in other ways of producing or saving energy.

Re:Generate a Vacuum (2, Informative)

Darkman, Walkin Dude (707389) | more than 4 years ago | (#31435738)

Indeed, especially when there are many alternatives available. Pumped storage hydro (which China is rolling out as fast as it can) is a good one, or if you just wanted to string HVDC lines between main networks, you can get a smoothed power supply because the wind is always blowing somewhere, see for reference the European supergrid concept.

Re:Generate a Vacuum (1)

nagnamer (1046654) | more than 4 years ago | (#31436148)

2 birds, 1 very expensive stone. It would probably cost a great deal of money to build tunnels, evacuate out almost all the air, and maintain that low atmosphere. Sure, it might save some energy of running the train, but the money and resources needed to do this would greatly outweigh any benefit. We are almost certainly much better off investing in other ways of producing or saving energy.

And build trains that can run in such conditions with a bunch of safety concerns akin to those you have when you're building an aircraft. But, I think it's a great idea, still.

Oil and coal are cheap. But they also create problems. I think a good solution deserves to have money thrown at it.

Re:Generate a Vacuum (0)

Anonymous Coward | more than 4 years ago | (#31435476)

But what happens if the train breaks down? Will people need space suits to get to the nearest exit from the tunnel?

Re:Generate a Vacuum (1)

MichaelSmith (789609) | more than 4 years ago | (#31435514)

But what happens if the train breaks down? Will people need space suits to get to the nearest exit from the tunnel?

Maybe oxygen masks.

Re:Generate a Vacuum (1)

nacturation (646836) | more than 4 years ago | (#31435620)

But what happens if the train breaks down? Will people need space suits to get to the nearest exit from the tunnel?

Maybe oxygen masks.

Connected to a tank of oxygen sufficiently large to fill the entire tunnel close to 1 atmosphere of pressure?

Re:Generate a Vacuum (1)

richard.cs (1062366) | more than 4 years ago | (#31435772)

But what happens if the train breaks down? Will people need space suits to get to the nearest exit from the tunnel?

Maybe oxygen masks.

Connected to a tank of oxygen sufficiently large to fill the entire tunnel close to 1 atmosphere of pressure?

Now that is a good idea. Since such a tank would be large we could store it external to the train and have valves along the length of the tunnel which can be remotely operated from on board the train. Perhaps we could confine this external source of air gravitationally rather than in a tank and call it the atmosphere?

Seriously though, that's all that would be needed. You could include one oxygen mask for someone to go out and open the next valve down if it gets stuck or something like that. Bear in mind that 3 psi isn't that low - humans are quite happy at that pressure if they're breathing pure oxygen - that's what was used on the apollo moon missions.

Been thought off and rejected as to complex (3, Insightful)

SmallFurryCreature (593017) | more than 4 years ago | (#31435784)

The problem is that trains need people on board who in general want to breath, spoiled brats they are.

So, the train would need an oxygen supply on board, added weight and explosion risk and a LOT of oxygen because people do a lot of breathing. It would also need to scrub the CO2 out, because it is after all a closed system.

Then the train needs to enter a normal area to let people in and out without explosive decompression.

It can be done, but is just not worth the hassle, especially when aerodynamics don't matter all that much for a train. The nose after all is only a small part of a LOOOOOOOOOOOONG train. The carriages don't add much to wind resistance, you can in a way decrease air-resistance per carried passenger by just carrying more passengers.

Re:Been thought off and rejected as to complex (2, Informative)

Gordonjcp (186804) | more than 4 years ago | (#31435918)

3psi is about atmospheric pressure at 40,000 feet - roughly where commercial airliners fly. Inside a commercial airliner the pressure altitude is around 8000-10000 feet, or about 11-10psi.

It's not entirely a solved problem, but it's not as bad as you think.

Re:Generate a Vacuum (0)

jamesh (87723) | more than 4 years ago | (#31435894)

Alternatively, build the cities underground and reduce the surface atmosphere to 0-3psi and run the trains on the surface. The surface will be uninhabitable in another 100 years anyway so we might as well make it useful for something.

advantages and disadvantages of compressed air (5, Informative)

FishTankX (1539069) | more than 4 years ago | (#31436008)

Sadly, tunnels large enough to carry trains, as modern subways will prove, are prohibitivley expensive.

however, compressed air is a good energy storage medium.

Assuming a 900 foot by 300 foot by 300 foot cavern was filled with compressed air with a pressure of 300 bars, would have a potential energy of roughly 50 gigawatt hours. (source: http://www.tinaja.com/glib/energfun.pdf [tinaja.com]) Or enough to run the entire united states for about an hour. This is a massive pool of energy, and significantly more cost effective than a battery.

HOWEVER, there lies a rub. When you compress air, you generate a massive amount of heat as the thermal energy stored in the air is highly compressed. This heat energy, unless properly reclaimed and stored (I.E. In a molten salt bath) just leaks away, stealing a huge chunk of the potential energy with it. When the air is uncompressed, there is significantly less heat energy stored in the air, and thus the expanded gas is very cold. This limits how far it can expand again, and creates a formidable problem in the form of condensation.

What you need to do to get EFFICENT compressed air storage, is either store the heat in an efficent manner, and add it back to the compressed air. OR you can gradually warm it back up to room temperature through a heat exchanger as it expands.

All in all, the challenges to attaining decent efficency are considerable.

What might be an easier way to achieve the same energy storage using similar principles, is to turn that same cavern they created into a giant hydro dam. Basically, create an enclosure of equal size below it. When energy needs to be stored, pump the water up to the higher cavern. When energy needs to be released, release it through hydro turbines into the lower cavern.

Re:advantages and disadvantages of compressed air (1)

FishTankX (1539069) | more than 4 years ago | (#31436014)

Oops. Sloppy editing. 50 gigawatt hours is roughly the amount of energy generated by a large nuke plant, in about a day.

Re:advantages and disadvantages of compressed air (0)

Anonymous Coward | more than 4 years ago | (#31436300)

300 bar in a volume the size of a scuba tank has enough explosive potential energy to level a suburban house.

That pressure in a 900*300*300 foot volume is something I do *not* want anywhere near me, at all, ever. Even an earth tremor that caused a minor fissure to form could eventually lead to explosive decompression.

Re:Generate a Vacuum (0)

Anonymous Coward | more than 4 years ago | (#31436098)

Alternatively we could build flat escalators from our front doors onto a major highway, "walk" everywhere quickly with minimal energy and power the whole thing with hamsters fed on organic cheese.

It would probably cost the same.

Re: Travelling with using hardly any energy (1)

kanweg (771128) | more than 4 years ago | (#31436330)

Even better (but not for generating energy): Make the trains levitate on magnets in the vacuum tube, and make the tube slope down away from the station. You get speed by going down the slope, lose little energy on the way, and at the destination the slope goes up, storing the energy for the next ride.

Bert
PS Don't do this in Chile

circus (-1, Troll)

Anonymous Coward | more than 4 years ago | (#31435220)

It has come to my attention that the entire Linux community is a hotbed of so called 'alternative sexuality', which includes anything from hedonistic orgies to homosexuality to paedophilia.

What better way of demonstrating this than by looking at the hidden messages contained within the names of some of Linux's most outspoken advocates:

  • Linus Torvalds [microsoft.com] is an anagram of slit anus or VD 'L,' clearly referring to himself by the first initial.
  • Richard M. Stallman [archive.org], spokespervert for the Gaysex's Not Unusual 'movement' is an anagram of mans cram thrill ad.
  • Alan Cox [microsoft.com] is barely an anagram of anal cox which is just so filthy and unchristian it unnerves me.

I'm sure that Eric S. Raymond, composer of the satanic homosexual [goatse.fr] propaganda diatribe The Cathedral and the Bizarre, is probably an anagram of something queer, but we don't need to look that far as we know he's always shoving a gun up some poor little boy's rectum. Update: Eric S. Raymond is actually an anagram for secondary rim and cord in my arse. It just goes to show you that he is indeed queer.

Update the Second: It is also documented that Evil Sicko Gaymond is responsible for a nauseating piece of code called Fetchmail [microsoft.com], which is obviously sinister sodomite slang for 'Felch Male' -- a disgusting practise. For those not in the know, 'felching' is the act performed by two perverts wherein one sucks their own post-coital ejaculate out of the other's rectum. In fact, it appears that the dirty Linux faggots set out to undermine the good Republican institution of e-mail, turning it into 'e-male.'

As far as Richard 'Master' Stallman goes, that filthy fudge-packer was actually quoted [salon.com] on leftist commie propaganda site Salon.com as saying the following: 'I've been resistant to the pressure to conform in any circumstance,' he says. 'It's about being able to question conventional wisdom,' he asserts. 'I believe in love, but not monogamy,' he says plainly.

And this isn't a made up troll bullshit either! He actually stated this tripe, which makes it obvious that he is trying to politely say that he's a flaming homo [comp-u-geek.net] slut [rotten.com]!

Speaking about 'flaming,' who better to point out as a filthy chutney ferret than Slashdot's very own self-confessed pederast Jon Katz. Although an obvious deviant anagram cannot be found from his name, he has already confessed, nay boasted of the homosexual [goatse.fr] perversion of corrupting the innocence of young children [slashdot.org]. To quote from the article linked:

'I've got a rare kidney disease,' I told her. 'I have to go to the bathroom a lot. You can come with me if you want, but it takes a while. Is that okay with you? Do you want a note from my doctor?'

Is this why you were touching your penis [rotten.com] in the cinema, Jon? And letting the other boys touch it too?

We should also point out that Jon Katz refers to himself as 'Slashdot's resident Gasbag.' Is there any more doubt? For those fortunate few who aren't aware of the list of homosexual [goatse.fr] terminology found inside the Linux 'Sauce Code,' a 'Gasbag' is a pervert who gains sexual gratification from having a thin straw inserted into his urethra (or to use the common parlance, 'piss-pipe'), then his homosexual [goatse.fr] lover blows firmly down the straw to inflate his scrotum. This is, of course, when he's not busy violating the dignity and copyright of posters to Slashdot by gathering together their postings and publishing them en masse to further his twisted and manipulative journalistic agenda.

Sick, disgusting antichristian perverts, the lot of them.

In addition, many of the Linux distributions (a 'distribution' is the most common way to spread the faggots' wares) are run by faggot groups. The Slackware [redhat.com] distro is named after the 'Slack-wear' fags wear to allow easy access to the anus for sexual purposes. Furthermore, Slackware is a close anagram of claw arse, a reference to the homosexual [goatse.fr] practise of anal fisting. The Mandrake [slackware.com] product is run by a group of French faggot satanists, and is named after the faggot nickname for the vibrator. It was also chosen because it is an anagram for dark amen and ram naked, which is what they do.

Another 'distro,' (abbrieviated as such because it sounds a bit like 'Disco,' which is where homosexuals [goatse.fr] preyed on young boys in the 1970s), is Debian, [mandrake.com] an anagram of in a bed, which could be considered innocent enough (after all, a bed is both where we sleep and pray), until we realise what other names Debian uses to describe their foul wares. 'Woody' is obvious enough, being a term for the erect male penis [rotten.com], glistening with pre-cum. But far sicker is the phrase 'Frozen Potato' that they use. This filthy term, again found in the secret homosexual [goatse.fr] 'Sauce Code,' refers to the solo homosexual [goatse.fr] practice of defecating into a clear polythene bag, shaping the turd into a crude approximation of the male phallus, then leaving it in the freezer overnight until it becomes solid. The practitioner then proceeds to push the frozen 'potato' up his own rectum, squeezing it in and out until his tight young balls erupt in a screaming orgasm.

And Red Hat [debian.org] is secret homo [comp-u-geek.net] slang for the tip of a penis [rotten.com] that is soaked in blood from a freshly violated underage ringpiece.

The fags have even invented special tools to aid their faggotry! For example, the 'supermount' tool was devised to allow deeper penetration, which is good for fags because it gives more pressure on the prostate gland. 'Automount' is used, on the other hand, because Linux users are all fat and gay, and need to mount each other [comp-u-geek.net] automatically.

The depths of their depravity can be seen in their use of 'mount points.' These are, plainly speaking, the different points of penetration. The main one is obviously/anus, but there are others. Militant fags even say 'there is no/opt mount point' because for these dirty perverts faggotry is not optional but a way of life.

More evidence is in the fact that Linux users say how much they love `man`, even going so far as to say that all new Linux users (who are in fact just innocent heterosexuals indoctrinated by the gay propaganda) should try out `man`. In no other system do users boast of their frequent recourse to a man.

Other areas of the system also show Linux's inherent gayness. For example, people are often told of the 'FAQ,' but how many innocent heterosexual Windows [amiga.com] users know what this actually means. The answer is shocking: Faggot Anal Quest: the voyage of discovery for newly converted fags!

Even the title 'Slashdot [geekizoid.com]' originally referred to a homosexual [goatse.fr] practice. Slashdot [kuro5hin.org] of course refers to the popular gay practice of blood-letting. The Slashbots, of course are those super-zealous homosexuals [goatse.fr] who take this perversion to its extreme by ripping open their anuses, as seen on the site most popular with Slashdot users, the depraved work of Satan, http://www.eff.org/ [eff.org].

The editors of Slashdot [slashduh.org] also have homosexual [goatse.fr] names: 'Hemos' is obvious in itself, being one vowel away from 'Homos.' But even more sickening is 'Commander Taco' which sounds a bit like 'Commode in Taco,' filthy gay slang for a pair of spreadeagled buttocks that are caked with excrement [pboy.com]. (The best form of lubrication, they insist.) Sometimes, these 'Taco Commodes' have special 'Salsa Sauce' (blood from a ruptured rectum) and 'Cheese' (rancid flakes of penis [rotten.com] discharge) toppings. And to make it even worse, Slashdot [notslashdot.org] runs on Apache!

The Apache [microsoft.com] server, whose use among fags is as prevalent as AIDS, is named after homosexual [goatse.fr] activity -- as everyone knows, popular faggot band, the Village People, featured an Apache Indian, and it is for him that this gay program is named.

And that's not forgetting the use of patches in the Linux fag world -- patches are used to make the anus accessible for repeated anal sex even after its rupture by a session of fisting.

To summarise: Linux is gay. 'Slash -- Dot' is the graphical description of the space between a young boy's scrotum and anus. And BeOS [apple.com] is for hermaphrodites and disabled 'stumpers.'

FEEDBACK

What worries me is how much you know about what gay people do. I'm scared I actually read this whole thing. I think this post is a good example of the negative effects of Internet usage on people. This person obviously has no social life anymore and had to result to writing something as stupid as this. And actually take the time to do it too. Although... I think it was satire.. blah.. it's early. -- Anonymous Coward, Slashdot

Well, the only reason I know all about this is because I had the misfortune to read the Linux 'Sauce code' once. Although publicised as the computer code needed to get Linux up and running on a computer (and haven't you always been worried about the phrase 'Monolithic Kernel'?), this foul document is actually a detailed and graphic description of every conceivable degrading perversion known to the human race, as well as a few of the major animal species. It has shocked and disturbed me, to the point of needing to shock and disturb the common man to warn them of the impending homo [comp-u-geek.net]-calypse which threatens to engulf our planet.

You must work for the government. Trying to post the most obscene stuff in hopes that slashdot won't be able to continue or something, due to legal woes. If i ever see your ugly face, i'm going to stick my fireplace poker up your ass, after it's nice and hot, to weld shut that nasty gaping hole of yours. -- Anonymous Coward, Slashdot

Doesn't it give you a hard-on to imagine your thick strong poker ramming it's way up my most sacred of sphincters? You're beyond help, my friend, as the only thing you can imagine is the foul penetrative violation of another man. Are you sure you're not Eric Raymond? The government, being populated by limp-wristed liberals, could never stem the sickening tide of homosexual [goatse.fr] child molesting Linux advocacy. Hell, they've given NAMBLA free reign for years!

you really should post this logged in. i wish i could remember jebus's password, cuz i'd give it to you. -- mighty jebus [slashdot.org], Slashdot

Thank you for your kind words of support. However, this document shall only ever be posted anonymously. This is because the 'Open Sauce' movement is a sham, proposing homoerotic cults of hero worshipping in the name of freedom. I speak for the common man. For any man who prefers the warm, enveloping velvet folds of a woman's vagina [bodysnatchers.co.uk] to the tight puckered ringpiece of a child. These men, being common, decent folk, don't have a say in the political hypocrisy that is Slashdot culture. I am the unknown liberator [hitler.org].

ROLF LAMO i hate linux FAGGOTS -- Anonymous Coward, Slashdot

We shouldn't hate them, we should pity them for the misguided fools they are... Fanatical Linux zeal-outs need to be herded into camps for re-education and subsequent rehabilitation into normal heterosexual society. This re-education shall be achieved by forcing them to watch repeats of Baywatch until the very mention of Pamela Anderson [rotten.com] causes them to fill their pants with healthy heterosexual jism [zillabunny.com].

Actually, that's not at all how scrotal inflation works. I understand it involves injecting sterile saline solution into the scrotum. I've never tried this, but you can read how to do it safely in case you're interested. (Before you moderate this down, ask yourself honestly -- who are the real crazies -- people who do scrotal inflation, or people who pay $1000+ for a game console?) -- double_h [slashdot.org], Slashdot

Well, it just goes to show that even the holy Linux 'sauce code' is riddled with bugs that need fixing. (The irony of Jon Katz not even being able to inflate his scrotum correctly has not been lost on me.) The Linux pervert elite already acknowledge this, with their queer slogan: 'Given enough arms, all rectums are shallow.' And anyway, the PS2 [xbox.com] sucks major cock and isn't worth the money. Intellivision forever!

dude did u used to post on msnbc's nt bulletin board now that u are doing anti-gay posts u also need to start in with anti-black stuff too c u in church -- Anonymous Coward, Slashdot

For one thing, whilst Linux is a cavalcade of queer propaganda masquerading as the future of computing, NT [linux.com] is used by people who think nothing better of encasing their genitals in quick setting plaster then going to see a really dirty porno film, enjoying the restriction enforced onto them. Remember, a wasted arousal is a sin in the eyes of the Catholic church [atheism.org]. Clearly, the only god-fearing Christian operating system in existence is CP/M -- The Christian Program Monitor. All computer users should immediately ask their local pastor to install this fine OS onto their systems. It is the only route to salvation.

Secondly, this message is for every man. Computers know no colour. Not only that, but one of the finest websites in the world is maintained by a Black Man [stileproject.com] . Now fuck off you racist donkey felcher.

And don't forget that slashdot was written in Perl, which is just too close to 'Pearl Necklace' for comfort.... oh wait; that's something all you heterosexuals do.... I can't help but wonder how much faster the trolls could do First-Posts on this site if it were redone in PHP... I could hand-type dynamic HTML pages faster than Perl can do them. -- phee [slashdot.org], Slashdot

Although there is nothing unholy about the fine heterosexual act of ejaculating between a woman's breasts, squirting one's load up towards her neck and chin area, it should be noted that Perl [python.org] (standing for Pansies Entering Rectums Locally) is also close to 'Pearl Monocle,' 'Pearl Nosering,' and the ubiquitous 'Pearl Enema.'

One scary thing about Perl [sun.com] is that it contains hidden homosexual [goatse.fr] messages. Take the following code: LWP::Simple -- It looks innocuous enough, doesn't it? But look at the line closely: There are two colons next to each other! As Larry 'Balls to the' Wall would openly admit in the Perl Documentation, Perl was designed from the ground up to indoctrinate it's programmers into performing unnatural sexual acts -- having two colons so closely together is clearly a reference to the perverse sickening act of 'colon kissing,' whereby two homosexual [goatse.fr] queers spread their buttocks wide, pressing their filthy torn sphincters together. They then share small round objects like marbles or golfballs by passing them from one rectum to another using muscle contraction alone. This is also referred to in programming 'circles' as 'Parameter Passing.'

And PHP [perl.org] stands for Perverted Homosexual Penetration. Didn't you know?

Thank you for your valuable input on this. I am sure you will be never forgotten. BTW: Did I mention that this could be useful in terraforming Mars? Mars rulaa. -- Eimernase [slashdot.org], Slashdot

Well, I don't know about terraforming Mars, but I do know that homosexual [goatse.fr] Linux Advocates have been probing Uranus for years.

That's inspiring. Keep up the good work, AC. May God in his wisdom grant you the strength to bring the plain honest truth to this community, and make it pure again. Yours, Cerberus. -- Anonymous Coward, Slashdot

*sniff* That brings a tear to my eye. Thank you once more for your kind support. I have taken faith in the knowledge that I am doing the Good Lord [atheism.org]'s work, but it is encouraging to know that I am helping out the common man here.

However, I should be cautious about revealing your name 'Cerberus' on such a filthy den of depravity as Slashdot. It is a well known fact that the 'Kerberos' documentation from Microsoft is a detailed manual describing, in intimate, exacting detail, how to sexually penetrate a variety of unwilling canine animals; be they domesticated, wild, or mythical. Slashdot posters have taken great pleasure in illegally spreading this documentation far and wide, treating it as an 'extension' to the Linux 'Sauce Code,' for the sake of 'interoperability.' (The slang term they use for nonconsensual intercourse -- their favourite kind.)

In fact, sick twisted Linux deviants are known to have LAN parties, (Love of Anal Naughtiness, needless to say.), wherein they entice a stray dog, known as the 'Samba Mount,' into their homes. Up to four of these filth-sodden blasphemers against nature take turns to plunge their erect, throbbing, uncircumcised members, conkers-deep, into the rectum, mouth, and other fleshy orifices of the poor animal. Eventually, the 'Samba Mount' collapses due to 'overload,' and needs to be 'rebooted.' (i.e., kicked out into the street, and left to fend for itself.) Many Linux users boast about their 'uptime' in such situations.

Inspiring stuff! If only all trolls were this quality! -- Anonymous Coward, Slashdot

If only indeed. You can help our brave cause by moderating this message up as often as possible. I recommend '+1, Underrated,' as that will protect your precious Karma in Metamoderation [slashdot.org]. Only then can we break through the glass ceiling of Homosexual Slashdot Culture. Is it any wonder that the new version of Slashcode has been christened 'Bender'???

If we can get just one of these postings up to at least '+1,' then it will be archived forever! Others will learn of our struggle, and join with us in our battle for freedom!

It's pathetic you've spent so much time writing this. -- Anonymous Coward, Slashdot

I am compelled to document the foulness and carnal depravity [catholic.net] that is Linux, in order that we may prepare ourselves for the great holy war that is to follow. It is my solemn duty to peel back the foreskin of ignorance and apply the wire brush of enlightenment.

As with any great open-source project, you need someone asking this question, so I'll do it. When the hell is version 2.0 going to be ready?!?! -- Anonymous Coward, Slashdot

I could make an arrogant, childish comment along the lines of 'Every time someone asks for 2.0, I won't release it for another 24 hours,' but the truth of the matter is that I'm quite nervous of releasing a 'number two,' as I can guarantee some filthy shit-slurping Linux pervert would want to suck it straight out of my anus before I've even had chance to wipe.

I desperately want to suck your monolithic kernel, you sexy hunk, you. -- Anonymous Coward, Slashdot

I sincerely hope you're Natalie Portman [archive.org].

Dude, nothing on slashdot larger than 3 paragraphs is worth reading. Try to distill the message, whatever it was, and maybe I'll read it. As it is, I have to much open source software to write to waste even 10 seconds of precious time. 10 seconds is all its gonna take M$ to whoop Linux's ass. Vigilence is the price of Free (as in libre -- from the fine, frou frou French language) Software. Hack on fellow geeks, and remember: Friday is Bouillabaisse day except for heathens who do not believe that Jesus died for their sins. Those godless, oil drench, bearded sexist clowns can pull grits from their pantaloons (another fine, fine French word) and eat that. Anyway, try to keep your message focused and concise. For concision is the soul of derision. Way. -- Anonymous Coward, Slashdot

What the fuck?

I've read your gay conspiracy post version 1.3.0 and I must say I'm impressed. In particular, I appreciate how you have managed to squeeze in a healthy dose of the latent homosexuality you gay-bashing homos [comp-u-geek.net] tend to be full of. Thank you again. -- Anonymous Coward, Slashdot

Well bugger me!

ooooh honey. how insecure are you!!! wann a little massage from deare bruci. love you -- Anonymous Coward, Slashdot

Fuck right off!

IMPORTANT: This message needs to be heard (Not HURD [linux.org], which is an acronym for 'Huge Unclean Rectal Dilator') across the whole community, so it has been released into the Public Domain [icopyright.com]. You know, that licence that we all had before those homoerotic crypto-fascists came out with the GPL [apple.com] (Gay Penetration License) that is no more than an excuse to see who's got the biggest feces-encrusted [rotten.com] cock. I would have put this up on Freshmeat [adultmember.com], but that name is known to be a euphemism for the tight rump of a young boy.

Come to think of it, the whole concept of 'Source Control' unnerves me, because it sounds a bit like 'Sauce Control,' which is a description of the homosexual [goatse.fr] practice of holding the base of the cock shaft tightly upon the point of ejaculation, thus causing a build up of semenal fluid that is only released upon entry into an incision made into the base of the receiver's scrotum. And 'Open Sauce' is the act of ejaculating into another mans face or perhaps a biscuit to be shared later. Obviously, 'Closed Sauce' is the only Christian thing to do, as evidenced by the fact that it is what Cathedrals are all about.

Contributors: (although not to the eternal game of 'soggy biscuit' that open 'sauce' development has become) Anonymous Coward, Anonymous Coward, phee, Anonymous Coward, mighty jebus, Anonymous Coward, Anonymous Coward, double_h, Anonymous Coward, Eimernase, Anonymous Coward, Anonymous Coward, Anonymous Coward, Anonymous Coward, Anonymous Coward, Anonymous Coward, Anonymous Coward, Anonymous Coward. Further contributions are welcome.

Current changes: This version sent to FreeWIPO [slashdot.org] by 'Bring BackATV' as plain text. Reformatted everything, added all links back in (that we could match from the previous version), many new ones (Slashbot bait links). Even more spelling fixed. Who wrote this thing, CmdrTaco himself?

Previous changes: Yet more changes added. Spelling fixed. Feedback added. Explanation of 'distro' system. 'Mount Point' syntax described. More filth regarding `man` and Slashdot. Yet more fucking spelling fixed. 'Fetchmail' uncovered further. More Slashbot baiting. Apache exposed. Distribution licence at foot of document.

ANUX -- A full Linux distribution... Up your ass!

Unwater Bags (5, Informative)

Black Gold Alchemist (1747136) | more than 4 years ago | (#31435228)

Another solution for the large scale storage of electricity is the inflation of airtight bags deep under water. Since water is so heavy, it exerts a lot of pressure against the air, leading to a cheap method of energy storage. The problem with all compressed-air systems is that have losses due to the non-isothermal nature of the process. That means some energy is lost as heat during compression, and you don't gain it all back thanks to Carnot. The energy density by volume is quite low, unfortunately, but in this application, that's basically irrelevant.

For the curious, the energy density of compressed gas, is 100*P*ln(P/A) kJ/m^3, where P is the maximum pressure and A is the ambient pressure. That m^3 term is in the volume when compressed.

material cost of bags is too high (0)

Anonymous Coward | more than 4 years ago | (#31435256)

cheaper to use salt caves, oilwells, etc etc

Re:material cost of bags is too high (1)

Black Gold Alchemist (1747136) | more than 4 years ago | (#31435280)

Yes, but eventually, you want to store more air than the free stuff can store, so you want to use the bags. The bags are useful for off-shore wind farms.

Re:material cost of bags is too high (2, Funny)

MichaelSmith (789609) | more than 4 years ago | (#31435416)

Yes, but eventually, you want to store more air than the free stuff can store, so you want to use the bags. The bags are useful for off-shore wind farms.

Ha! wind bags. I knew they had to be good for something.

Re:material cost of bags is too high (1)

Noodlenoggin (1295699) | more than 4 years ago | (#31435420)

Yeah, my old bag is full of hot air.

Re:material cost of bags is too high (1)

MichaelSmith (789609) | more than 4 years ago | (#31435468)

New Zealand has a lot of little streams and they all seem to have names. One day on south island I crossed a bridge where the stream was named "wind bag". I guess the stream namer was having a bad day.

Re:Unwater Bags (3, Interesting)

superposed (308216) | more than 4 years ago | (#31435616)

I think the losses in the CAES system are due to the fact that it is a non-adiabatic process (a diabatic process?, i.e. one where heat can be lost from the system). When you compress the air, the temperature rises, and some heat is lost to the surrounding ground. But if the cycles are fast enough, those losses may be reduced -- i.e., you allow the air to re-expand, which cools it, and it sucks heat back from the ground. Since heat moves slowly through the ground, you may be able to get a lot of it back before it goes anywhere. The innovation in the Alabama system was to use waste heat in the turbine's exhaust gases to replace this lost heat as well.

I think the solution you propose is isobaric (constant pressure) and isothermal (constant temperature), but still not adiabatic. Some of the energy used to compress the air is converted to heat, and that heat would be lost to the ocean instead of raising the temperature of the air.

A better solution might be to use pre-inflated air bags (or air boxes?) attached to pulleys on the bottom of the ocean. Use a motor to pull the other end of the rope, and you would draw the air bag downward, storing energy. Play out the rope and the rising air bag would turn the motor (now acting as a generator), generating electricity. You could also do this with stones or bags of silt/gravel, just raising and lowering them from the surface.

The problem is, you would need a lot of air bags or stones to store any significant amount of energy. If the stones or gravel have a density of 2000 kg/m^3 (similar to "Gravel, wet" according to http://www.simetric.co.uk/si_materials.htm [simetric.co.uk], higher than "Clay, wet excavated" (1600) but lower than concrete (2400)), then they will have a net weight in water of about 1000 kg/m^3 (i.e., a downward force of about 10000 Newtons per m^3). Air bags would exert a similar force upward. If you can find a near-shore location with a depth of 1 km, you could store 10000 N * 1000 m = 10 MJ of energy per cubic meter of material, which is about 3 kWh/m^3. A 100 MW wind farm (presumably closer to shore) would generate 100,000 kWh of electricity per hour when the wind is blowing, so if you wanted to store 6 hours of energy from this wind farm, you would need to raise and lower about 6 * 100,000 / 3 = 200,000 cubic meters of stone or air (e.g., 200 large chunks, each 10 meters across). I suppose it could be done...

Re:Unwater Bags (2, Interesting)

richard.cs (1062366) | more than 4 years ago | (#31435810)

the losses in the CAES system are due to the fact that it is a non-adiabatic process

the solution you propose is isobaric (constant pressure) and isothermal (constant temperature)

Either an adiabatic or an isothermal process will allow high efficiency. In the adiabatic process the heat from compression is stored in the air and in principle no energy is lost through the compression and decompression. In an isothermal process all of the extra heat from the compression is transferred to some external reservoir (ocean, atmosphere, etc). If this heat is transferred back to the air when decompression occurs the air leaves the system at its original temperature (as for an adiabatic process) and no energy is lost. An isothermal system can actually store more energy since the stored air is at low temperature and hence a greater quantity may be stored within a given volume and pressure limit.

In real systems what happens is heat is lost during compression and in storage and that heat is not fully returned to the system during decompression. The air leaves at a lower temperature and energy is lost. Some compressed air energy storage schemes have resorted to using natural gas to reheat the air since heat exchangers for a true isothermal process are impractically large.

Bags under houses (1)

kubitus (927806) | more than 4 years ago | (#31436314)

I suggest another idea - but this is not applicable in the US and CAN because of how they build houses: 2by4 and plywood.

.

A brick or stone built house of app. 100m^2 placed on a flat pressurized air-bag can store 3 days of average energy consumption of a household by pumping it up by 3 inches ( 8 cm )

Additional benefit: cushioning against earthquakes.

This idea claims to be prior art for any patent claim coming thereafter!

Efficiency (1)

JW CS (1593833) | more than 4 years ago | (#31435248)

So this is more efficient than just storing the electricity? That must say something about the sad state of current battery technology.

Re:Efficiency (1)

MichaelSmith (789609) | more than 4 years ago | (#31435302)

Well, its a way of storing the energy. Another way is to time shift. Drop the price when you have a lot of supply so that customers can charge their cars and heat their houses and water tanks using cheap power.

Re:Efficiency (2, Interesting)

Rei (128717) | more than 4 years ago | (#31435342)

No. It's far *less* efficient. Li-ion batteries have round-trip efficiencies in the 90s (some chemistries in the upper 90s). Compressed air storage has a round trip efficiency generally under 50%. Sometimes significantly.

There was an interesting article the other day about storing electricity in molten aluminum/alumina -- basically, turning today's electrolysis method of making aluminum into a reversible process. They claim to already have better than lead-acid prices, but far longer cycle life, as well as li-ion energy density. Could be interesting, although I haven't seen an efficiency stat. Also, since it runs hotter than a Zebra cell, I doubt it'd scale down well. But who knows.

Re:Efficiency (2, Interesting)

Black Gold Alchemist (1747136) | more than 4 years ago | (#31435388)

No. It's far *less* efficient.

There was an interesting article the other day about storing electricity in molten aluminium/alumina

We already have fuel cells that consume aluminium. They're only about %40 efficient, but they are 100-1000 times cheaper than hydrogen fuel cells. So, without any technology development, the "aluminium economy" is %25 efficient (%70 percent efficient electrolysis, %40 percent efficient fuel cell). I think if you re-designed an aluminium fuel cell, you could get 90 percent efficiency, so you would have overall %60 efficiency. Not great, but it works. My idea is to use the ZEBRA electrolyte, (or maybe another electrolyte like it) to avoid corrosion and inefficiency in the al-air fuel cell.

Re:Efficiency (3, Interesting)

vtechpilot (468543) | more than 4 years ago | (#31435546)

Your right that compressed air is a less energy efficient storage medium than Li-ion batteries, but only for the first couple of years. Li-ion battery storage capacity decreases at about 20% a year because of natural degradation. Consider the cost to frequently manufacture, replace and dispose of batteries compared to the wear cycles of a compressed air container which is probably measured in decades.

My point here is that the maintenance cost for compressed air energy storage is quite low compared to other options. You also have to consider the cost of making the storage devices. Steel tanks are mostly hollow and we are already really good at making them. We are good at recycling steel too. Air storage, unlike fuel cells or batteries options which consume lots of metals and require complex electronics to regulate, compressed air is extremely cheap and simple.

If our choice is cheap simple but supposedly inefficient storage of 50% via compressed air or storing 0% via other supposedly more efficient but unaffordable and unsustainable methods the choice is pretty simple.

Re:Efficiency (1)

Black Gold Alchemist (1747136) | more than 4 years ago | (#31435588)

AFAIK, that capacity decrease is does not effect efficiency, only the energy stored. You are right that battery wear-out is a huge cost that is often not taken into account with electric vehicles. If the battery lasts 3000 cycles and you get the batteries at 2 watt-hours/dollar, then the electricity stored over it's lifetime is only 0.6 dollars. (3000 cycles * 2 watt-hours is 6 kWh, so at 0.10 dollars/kWh = 0.6 dollars). That means that although that nice Tesla uses 250 watt-hours/mile = 0.025 cents/mile of electricity, battery wear-out means that you pay 0.083 in battery wear-out costs. Total 0.11 dollars.

Re:Efficiency (1)

dltaylor (7510) | more than 4 years ago | (#31435828)

Stress fractures in the tanks however "constructed" due to the frequently shifting internal pressure (think aircraft hulls that undergo a lot of pressure cycles, like the "convertible" Aloha 737)?

Pumps don't need maintenance or experience wear?

Losses in the gears or generator/motor sets to drive the pumps from the windmills?

It's easy forget all of those costs.

Re:Efficiency (1)

Calinous (985536) | more than 4 years ago | (#31435362)

In the case of the 1991 plant mentioned, creating that underground cave had as a side effect the extraction of huge quantities of salt (by the way, drilling and dissolving is the current method to extract salt). So, in that case you could have had the cave created for free, unlike batteries (or superconductor rings, or rotating masses, or water storage, or whatever else).

Re:Efficiency (1)

afidel (530433) | more than 4 years ago | (#31435566)

drilling and dissolving is the current method to extract salt
There's still significant mines under the great lakes being mined using traditional methods ala coal mining. I think this method will work great for areas without significant hills but gravity water storage is significantly more efficient so areas where the wind farm is on a large ridgeline will probably go that route.

Re:Efficiency (2, Interesting)

Tatarize (682683) | more than 4 years ago | (#31435898)

No. You could use anything from an efficient spinning wheel with a lot of potential energy and very little friction (think super heavy pottery wheel with an engagable generator/motor) to a super-conductive coil (or looped superconductive powerline) to just stash the energy for a bit. And these will almost certainly be more efficient.

The larger problems is that we don't have enough wind to care right now, and the problem of energy storage has nothing to do with wind. It's a modular problem that simply deals with electricity on the grid, if electricity storage is needed for the inconsistent power on the grid, then it's needed. The fact that it's needed for wind power isn't something of any consideration. Such problems should have a healthy amount of encapsulation.

The total amount of battery power on the planet could power our electrical needs for ten minutes. That's not enough. It's a problem, who cares where the power comes from. This crap reminds me of that stupid idea of building another power grid for renewable power so people could know the power they get is from renewable sources. WTF.

If compressed air works well as a battery it works well as a battery, my guess is that it almost certainly doesn't work well as a battery and the failure that is the air car is quite telling of that point. Even when you can control for everything (unlike a hole in the ground (see carbon capture)) you still can't compress and get power back at anything close to efficient enough to give it a second thought.

Load leveling Vs. Supply leveling (4, Insightful)

ductonius (705942) | more than 4 years ago | (#31435274)

The problem with these energy storage techniques for renewables is every single one of them would be more economical if they were used as load leveling systems (suck extra energy during down times, release in peak hours) rather than supply leveling systems (suck extra energy in high production hours, release it in low production hours).

The reason for this is day-to-day and monthly power consumption is a very easy thing to predict, so we know very well how much storage we need and if it will or will not be enough. Using these systems we can level the load and allow the greenest power sources (nuclear, followed by hydro) to produce the vast majority of power we need (because they can run at near 100% 24/7).

The wind is a very much harder thing to predict. So how much storage is needed? Who knows. What we DO know is that every single wind power station is going to need gas turbine backups for when a) the wind doesn't blow, b) demand is high and c) storage is depleted.

Using energy storage to allow nuclear and hydro to run most economically is a far better choice than using it to level the output of wind power.

Re:Load leveling Vs. Supply leveling (2, Insightful)

Black Gold Alchemist (1747136) | more than 4 years ago | (#31435312)

Compressed air is a good load leveller because of it's high power density. Superconducting energy storage is also a good load leveller, but really expensive.

I think the best way to store the energy long term would be to make synthetic gasoline (maybe natural gas) by reacting hydrogen with carbon dioxides. There has been research in the past about the electrolysis of carbonate solutions to produce hydrocarbons.

Re:Load leveling Vs. Supply leveling (1)

Will.Woodhull (1038600) | more than 4 years ago | (#31435520)

AFAIK, high speed flywheel storage is the best general purpose means of storing power.

That said, if there are geologic formations that could be exploited for compressed air storage, or topographic features that could be exploited for hydro storage, then in those situations it would make sense to do so.

Here's an interesting exercise: coal is currently mined in the North American Rocky Mountains and shipped down to nearly sea level by train to its point of use. If these trains used regenerative braking to charge flywheel batteries mounted on gimbals in special cars, how much electricity could be captured as each tonne of coal is dropped several thousand feet?

Re:Load leveling Vs. Supply leveling (1)

Black Gold Alchemist (1747136) | more than 4 years ago | (#31435558)

Flywheel energy storage is nice, but expensive. It's too scary to have an automobile that is purely powered by flywheels, but you can have a hybrid. You just have to be really careful about the possibility of the flywheel flying apart.

As for the train slowdown, about 8 megajoules of energy will be produce for every 3000 ft of decent at %100 efficiency. At the same time, a ton of coal contains 25827 megajoules of energy. So the energy of the fall is about %0.03 of the combustion energy.

Re:Load leveling Vs. Supply leveling (0)

Anonymous Coward | more than 4 years ago | (#31435606)

Sounds like we need a small black hole in the vicinity of the destination in order to improve upon this. Perhaps the payback of the LHC will be more than simply scientific knowledge.

Re:Load leveling Vs. Supply leveling (0)

Anonymous Coward | more than 4 years ago | (#31435948)

How could that help?

Re:Load leveling Vs. Supply leveling (2, Interesting)

Anonymous Coward | more than 4 years ago | (#31435358)

Hydro isn't always an option, and even though nuclear would go a long way to solving these problems, it also has limitations. For one, nuclear plants need coolant, which is generally a lake or river (again, geographically specific). For another, the FUD about nuclear energy isn't going away, so a lot of suitable areas won't be considered. Now, I'm not saying wind isn't similarly limited; but I am saying that wind power may work in places where neither hydro or nuclear will (dry, arid climates leap to mind). For the places where all three are an option (or similar energy storage techniques, such as alternately pumping/draining water between two adjacent bodies of water), all the better.

Honestly, why is it that people think JUST solar or JUST hydro or JUST $hyped_fuel_source is the answer? Unless we develop cold fusion at some point soon, our power will probably be taken from whichever the easiest source is at any given location, and we'll have a cornucopia of power stations - and maybe even distributed power generation (solar panels on peoples' roofs)!

Nobody thinks "Only Solar" (0)

Anonymous Coward | more than 4 years ago | (#31436426)

Nobody thinks "Only Solar". It's used as a strawman for saying why we can't use solar. Nobody thinks it must be "only solar". However, many people do seem to think that the only answer is nuclear.

Go figure.

But what renewables have in spades are two features nuclear/coal don't have:

1) low startup times. you can use a 1% complete windfarm, you can't use a 1% complete nuclear power station
2) resilience. you lose a turbine, you lose a lot of generation capacity from a traditional power station. Not so much from a 500-turbine wind farm

Re:Load leveling Vs. Supply leveling (-1, Flamebait)

0WaitState (231806) | more than 4 years ago | (#31435370)

I have mod points, but there's no "-1 stupid" option so I'm replying instead.

The wind is not hard to predict on a macro level. You build in spots that have consistent winds with a better-than-oil economically viable percentage days out of the year. The whole gist of the article is storage systems for wind power so that it can be tapped in the off-hours.

Re:Load leveling Vs. Supply leveling (1)

Calinous (985536) | more than 4 years ago | (#31435404)

Hydro can not produce 100% energy all the time, as the power plant is usually more powerful than the average water production in that basin. Also, when expecting heavy rains, the hydro plants will empty the lake behind the dam, and the power decreases due to lower water level differences (maximum power is when the lake is full, but this is bad if heavy rains come)

Re:Load leveling Vs. Supply leveling (2, Informative)

DamonHD (794830) | more than 4 years ago | (#31435470)

"What we DO know is that every single wind power station is going to need gas turbine backups for when a) the wind doesn't blow, b) demand is high and c) storage is depleted."

The amount needed depends on many factors such as the amount of demand control too.

So it's a grave error to think that all wind supply needs 100% callable backup, IMHO.

Rgds

Damon

Re:Load leveling Vs. Supply leveling (2, Insightful)

superposed (308216) | more than 4 years ago | (#31435676)

You are using a false dichotomy here. In fact the best approach is to use all available flexibility to improve the match between supply and demand. There is no need to smooth out either supply or demand on a one-to-one basis. Instead, you use a smaller amount of flexible assets (hydro, pumped hydro, air storage, fast-start gas generators, electric vehicle chargers, price-sensitive customers, etc.) to fill in the gaps between the two. To the extent that variations in supply and demand (or between different locations) are uncorrelated, you can take advantage of statistical smoothing and get more bang for your buck by smoothing out the whole portfolio.

It is likely that there will be days when loads are fairly high and wind power production in the same region is relatively low. It is less likely that solar would also be low on those days. If you have customers who are willing to use less power on these rare occasions, then you can take advantage of that. If not, it doesn't cost much to build a few natural gas turbines that you only run on these rare occasions.

See, e.g., http://users.ox.ac.uk/~cenv0115/ [ox.ac.uk]

Re:Load leveling Vs. Supply leveling (2, Informative)

Darkman, Walkin Dude (707389) | more than 4 years ago | (#31435760)

The wind is a very much harder thing to predict. So how much storage is needed? Who knows. What we DO know is that every single wind power station is going to need gas turbine backups for when a) the wind doesn't blow, b) demand is high and c) storage is depleted.

Many studies [wikipedia.org] have been done on this subject. You appear to be a bit confused as to the purpose of load levelling systems in proposed green energy schemes.

Re:Load leveling Vs. Supply leveling (1)

FishTankX (1539069) | more than 4 years ago | (#31436022)

One small bit to add to this. Nuclear wouldn't be the best candidate for this load leveling because running the nuclear plant at full blast 24 hours a day would significantly reduce it's lifespan. It's already hard as nails to get a nuclear plant BUILT, having to retire them 20 years early because they were worked to the bone and failed due to radiation damage and pressure damage would be a tragedy.

Compared to pumped hydro (4, Informative)

steveha (103154) | more than 4 years ago | (#31435292)

The first question I thought of was, "Why not just use pumped hydro power?" Then, oddly enough, I read TFA and found the answer in it:

The nation's largest energy storage option right now is pumped hydroelectricity. When excess electricity is present in a system, it can be used to pump water up to a reservoir. Then, when that power is needed, the water is sent through a turbine to generate electricity. The U.S. electric system has 2.5 gigawatts of pumped hydro storage capacity, but most of the good, cheap sites are already occupied, and creating new reservoirs is not environmentally benign.

And, as noted in the summary, compressed air energy storage (CAES) been tried and it works:

'We expect the CAES plant technology pioneered in Alabama to lead to widespread application in this country," said Robert Schainker, the manager of the Electric Power Research Institute's Energy Storage Program in a press release announcing the plant's completion. 'Three fourths of the United States has geology suitable for underground air storage. At present, more than a dozen utilities are evaluating sites for CAES application."

steveha

Re:Compared to pumped hydro (1)

Statecraftsman (718862) | more than 4 years ago | (#31435436)

Problem is a gigawatt isn't a measure of storage capacity, it's a rate equal to 1 billion Joules per second. Still, doing some quick calcs I conclude that this is actually a great way to store energy. I'm looking forward to better electricity prices in the future.

Re:Compared to pumped hydro (1)

Ruke (857276) | more than 4 years ago | (#31435670)

I'm looking forward to better electricity prices in the future.

Regarding pumped hydro? Sorry, this isn't a "future" thing. This is a "we're already doing it, and have in fact exhausted our capacity" thing.

Re:Compared to pumped hydro (1)

Darkman, Walkin Dude (707389) | more than 4 years ago | (#31435774)

Hows that, countries like China are putting our PSH as fast as they can - as well as which there are salt water storage PSH facilities currently active in Japan, and recent technological developments allow for much lower height PSH reservoirs. It would appear the compressed air guys haven't been keeping up with the news.

Re:Compared to pumped hydro (1)

ledow (319597) | more than 4 years ago | (#31435896)

Not just that... pumping water is a lot harder than pumping air - just through sheer mass moved. The mass thing does affect stuff on the way out too, so air can't "push" as big a turbine as water would but everything like that just creates more strain on the equipment. Additionally, water is completely incompressible, so if you want to store 10,000 litres, you have to have 10,000 litres of space (and thus a large environmental concern and also restricts the power you can produce in a certain area. However, air can be compressed incredibly well (someone was talking about 1000psi - that's nearly 700 times more than atmospheric pressure) using quite simple technology and thus you only need one-seven-hundreth of the space (or you get 700 times more "fuel" into the same space). It has to be air-tight but that problem almost solves itself in deep underground caves, which is why we're not all swimming in natural gas at the moment.

Re:Compared to pumped hydro (1)

captainpanic (1173915) | more than 4 years ago | (#31436266)

Just build a second (relatively small) reservoir at the base of the dam.
Then install additional pumps and turbines. The capacity of the main reservoir is adequate for weeks of electricity production - so the bottleneck is in the bottom reservoir and the pump/turbine capacity.

Huh? (1)

Fishbulb (32296) | more than 4 years ago | (#31435330)

Pumping stuff into the ground that isn't normally there tends to give me the willies anymore. "Stick it where the sun don't shine!" isn't such a great solution, IMO.

Besides which, why not just build Vanadium batteries [discovermagazine.com] or invest in carbon nanotube [popularmechanics.com] ultra-capacitors [arstechnica.com] (which could have direct benefit to mobile energy storage)?

Re:Huh? (1)

Black Gold Alchemist (1747136) | more than 4 years ago | (#31435412)

That's all really, really, expensive. When you here the word nano, you should think $1000/gram, completely unprofitable technology. Mechanical and simple chemical systems are the future, because they are cheap. They might not be pretty, they might be slightly less efficient, but they will be much more reliable. They're pumping air into the ground. it's not really all that bad.

Re:Huh? (1)

mbone (558574) | more than 4 years ago | (#31436244)

They're pumping air into the ground. it's not really all that bad.

Of course, if they fracture the roof of the salt dome, and it caves in and a sink hole swallows up whatever town is above them on the surface, that could be [cbsnews.com] considered to be bad [tele2.nl].

Re:Huh? (1)

Calinous (985536) | more than 4 years ago | (#31435418)

Cost is an issue - there are plenty of old mines that can be used for compressed air storage (by the way, pumped air inside mine shafts was used as "air reservoir" for a wind tunnel - I think for the nuclear reaction-powered jet engines.

Re:Huh? (1)

mlush (620447) | more than 4 years ago | (#31436312)

Pumping stuff into the ground that isn't normally there tends to give me the willies anymore. "Stick it where the sun don't shine!" isn't such a great solution, IMO.

Exactly what could go wrong? I suppose the pressure cave could rupture and you get an air volcano, so don't build on top of it. Pockets of gas under pressure are nothing new in the earths crust.

Besides which, why not just build Vanadium batteries [discovermagazine.com] or invest in carbon nanotube [popularmechanics.com] ultra-capacitors [arstechnica.com] (which could have direct benefit to mobile energy storage)?

What is the duty cycle on Vanadium batteries, carbon nanotubes and ultra-capacitors? The battery in CAEF is just a big cave with little to wear out..

Max Pressure? (1)

religious freak (1005821) | more than 4 years ago | (#31435356)

I'm curious... I wonder how high the psi could get before something broke. I mean, the weak link would definitely be the seal (one would think). I suppose you could get some pretty dense air underground... very interesting idea.

Re:Max Pressure? (1)

MichaelSmith (789609) | more than 4 years ago | (#31435390)

I'm curious... I wonder how high the psi could get before something broke. I mean, the weak link would definitely be the seal (one would think). I suppose you could get some pretty dense air underground... very interesting idea.

It would make a great Michael Bay movie.

Re:Max Pressure? (1)

Hognoxious (631665) | more than 4 years ago | (#31435596)

It would make a great Michael Bay movie.

Only if I could watch it on a DRM-free Blu-ray disk with a cheap Mac.

Re:Max Pressure? (1)

nacturation (646836) | more than 4 years ago | (#31435658)

It would make a great Michael Bay movie.

Only if I could watch it on a DRM-free Blu-ray disk with a cheap Mac.

You forgot to ask for a pony too.

Re:Max Pressure? (0)

Anonymous Coward | more than 4 years ago | (#31436248)

I think a unicorn or pegasus might be more appropriate.

Re:Max Pressure? (1)

clarkkent09 (1104833) | more than 4 years ago | (#31435554)

I would think you pump's maximum psi rating would be the weakest point. Nothing would break, you just couldn't pump in any more air.

Re:Max Pressure? (1)

religious freak (1005821) | more than 4 years ago | (#31435610)

In the event of normal operation, but in the event of catastrophic failure? Hmm, interesting. I guess when I hear new ideas (new to me anyway) the first thing I think is how they may break.

If your seal didn't hold as you thought it would or your readings were incorrect, or there was geological instability... hmm... well, it's a novel concept. I look forward to hearing more about it someday.

compressors are the weak link (3, Informative)

nido (102070) | more than 4 years ago | (#31435614)

I mean, the weak link would definitely be the seal (one would think).

I, for one, think that the weak link would be the compressors. Most gas pumps just aren't especially efficient. If only someone would invent a pump that's better than current designs [wikipedia.org], the world's energy problems could be quickly solved.

Here's what the N.Y. Times article said:

The McIntosh plant uses an electric motor and a compressor to pressurize an underground chamber of 19 million cubic feet -- 220 feet in diameter and 1,000 feet tall -- to 1,100 pounds per square inch. The pressure may sound high, but it is only about one-fifth of what the chamber could withstand.

The chamber in Alabama could hold 5,500 psi, but the pump is only capable of 1,100 psi. Design a better pump, and the cavern could store significantly more air.

The real info about dispatching wind power (5, Informative)

Animats (122034) | more than 4 years ago | (#31435360)

This is the Slashdot-misunderstood version of the Wired dumbed-down version. Here's some of the more serious stuff.

Wind Operations Dispatching Training [pjm.com]: This is the grid system operator's view of wind power.

There's a lot going on. Since electricity deregulation, the power distribution companies don't own much generation capacity. They buy power from generating companies. So there's a market system and contracts in place. The contracts are now more long-term; the "auction every half hour" scheme California had for a few years is out of favor. Now, the planning horizon is about one day.

There's a whole series of PJM online courses [pjm.com], and if you go through some of the basic ones, you'll be able to talk about electric power intelligently.

Re:The real info about dispatching wind power (-1, Offtopic)

Anonymous Coward | more than 4 years ago | (#31435510)

posting to remove incorrect mod.

Perpetuum mobile, anyone? (0)

Anonymous Coward | more than 4 years ago | (#31435366)

So, the idea is to get more power by letting the air out, than consume it to pump the air in?

Re:Perpetuum mobile, anyone? (0)

Anonymous Coward | more than 4 years ago | (#31436408)

The idea is to pump air in to *store* energy. Not generate it. Think of it like you think of batteries.

Numbers from second article (4, Informative)

steveha (103154) | more than 4 years ago | (#31435384)

As a result, the plant produces one kilowatt-hour -- or 1,000 watt-hours -- of electricity for each 870 watts consumed the previous night. In contrast, the most common mode of energy storage is pumped hydro, in which water is pumped uphill at night, and during the day a valve is turned and the water runs back down, with the pumps recapturing the mechanical energy and turning it into electricity. But in that system, each kilowatt-hour put in delivers no more than 700 or 750 watts back out again. Batteries have about the same ratio.

I assume we should reverse those first numbers: we spend 1,000 watt-hours to gain 870 watt-hours later. Cool to see that it beats pumped hydro.

http://www.nytimes.com/1991/09/29/business/technology-using-compressed-air-to-store-up-electricity.html [nytimes.com]

Hydroelectric plants often cost $1,000 per kilowatt of capacity, and batteries cost far more. The cost of building the Alabama plant was about $550 per kilowatt of capacity.

And it's cheaper than pumped hydro!

The American plant has one new twist, however: the exhaust gases from the turbine are used to preheat the compressed air after it is brought up from the cavern. That makes it 25 percent more efficient than its German predecessor, the institute says.

Interesting. Of course, if you use this with a wind farm, you don't get this benefit; the plant discussed here is a coal plant, with plenty of waste heat.

The above article is from 1991. Despite all these advantages, the idea never took off before now. It saved money, but not a huge amount. But since the wind blows when it blows, not when you want it to blow, I can see this being a useful thing for a wind farm.

steveha

Re:Numbers from second article (1)

MattskEE (925706) | more than 4 years ago | (#31435428)

As a result, the plant produces one kilowatt-hour -- or 1,000 watt-hours -- of electricity for each 870 watts consumed the previous night.

Not to mention they have made the classic mistake of confusing Power and Energy. Watt-hours is an energy because it has units of Joules. Watts are in the form of Joules/second which simply represents how quickly you are transferring energy from one place or form to another.

Re:Numbers from second article (1)

Darkman, Walkin Dude (707389) | more than 4 years ago | (#31435790)

Em those numbers are wrong. Even 1960s-era PSH like Turlough Hill in Ireland get in the mid to high 80s returns, and modern systems aget in the 90s very easily. As for the 1991 costing, I'll say nothing.

Conversion losses (2, Interesting)

spectrokid (660550) | more than 4 years ago | (#31435662)

Wind -> Electricity ->compressed air ->electricity. That should give some serious losses. On top of that, windmills have gearboxes, brakes and all kinds of complicated crap to make them run perfectly in sync with the phase of the power grid. So question is, would it not be cheaper to mount a basic compressor in the nacelle and have it run directly on the axle, then pump the air through a set of pipes. Yes pipes have losses too, but remember the main cost of the windmill is its purchase, so a cheaper design might pay off?

Re:Conversion losses (0)

Anonymous Coward | more than 4 years ago | (#31435720)

It is unlikely that the windfarm is located in a suitable place to build the compressed air storage mechanism. Generating electricity from wind is well proven and the storage site can be placed anywhere within reach of the grid. The economic considerations of building the infrastructure typically outweigh other considerations such as generating efficiency. You can have a very efficient process but it isn't very useful if you can't economically get the product to market. At the end of the day it's all about the capacity delivered to the grid.

Doing it with water (2, Informative)

mbone (558574) | more than 4 years ago | (#31436180)

People have been storing electrical energy using water for a long time (over a century). The basic idea is the same, but in the case of water and hydroelectric dams, the solution is easier (you just run the turbines as pumps, putting water into the resevoir instead of letting it drain out). According to the wikipedia article on Pumped-storage hydroelectricity [wikipedia.org] :


In 2009 the United States had 21.5 GW of pumped storage generating capacity, accounting for 2.5% of baseload generating capacity. PHS generated (net) -6288 GWh of energy in 2008 ...

In 2007 the EU had 38.3 GW net capacity of pumped storage out of a total of 140 GW of hydropower and representing 5% of total net electrical capacity in the EU.

And, yes, people have considered [cam.ac.uk] using pumped-storage hydroelectric to even out the variation in wind power.

I myself doubt that compressed air storage would ever amount to more than a fraction of pumped hydro-electric storage, but it might be useful in very dry or very flat regions.

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