like something out of the Aeneid!
September 24, 2014 5:16 PM Subscribe
"A new electricity distribution system being described as the "'Hoover Dam' of the 21st century" will bring wind energy from Wyoming to customers in California—and it will get there by way of a $1.5 billion artificial cave built specifically for storing air inside a salt dome in Utah. "
the direction of some of these alternative energy sources seem likely to pave the way forward.
but will they be enough to satiate our nuka-cola hangover?
obligatory cold fusion link
the direction of some of these alternative energy sources seem likely to pave the way forward.
but will they be enough to satiate our nuka-cola hangover?
obligatory cold fusion link
Wait, what?? We're storing energy by compressing air in a big subterranean chamber, then getting it back by driving a turbine with escaping air?
Is this really a efficient method of storing power, compared to, say, plain old batteries? Someone hope me.
posted by JHarris at 5:40 PM on September 24, 2014
Is this really a efficient method of storing power, compared to, say, plain old batteries? Someone hope me.
posted by JHarris at 5:40 PM on September 24, 2014
Is this really a efficient method of storing power, compared to, say, plain old batteries?
Yeah, it really is. Alternative methods are to pump water uphill and then let it turn turbines on the downhill run.
The main problem is that at the scales we are talking about here, batteries don't scale well, they aren't that efficient, and they are expensive besides. Mechanical systems can store a lot more energy, a lot easier, and at far lower cost.
posted by Pogo_Fuzzybutt at 5:44 PM on September 24, 2014 [19 favorites]
Given how terrible batteries remain, I wouldn't be surprised.
posted by ChurchHatesTucker at 5:46 PM on September 24, 2014
posted by ChurchHatesTucker at 5:46 PM on September 24, 2014
There are similar systems proposed for storing energy from offshore wind farms in underwater bags of compressed air. For example, Hydrostor
I think that the advantages are that you don't need tons of nasty, rare metals, the system can store energy for longer, and you can build it to basically any scale. According to wikipedia the energy density of compressed air is on par with lead-acid batteries. There are some disadvantages, like batteries release their energy at a more constant rate than pressure vessels. There are some advantages, that pressure vessels can discharge their energy faster, which can be good for applications like vehicles where you might want to accelerate quickly.
posted by rustcrumb at 5:46 PM on September 24, 2014
I think that the advantages are that you don't need tons of nasty, rare metals, the system can store energy for longer, and you can build it to basically any scale. According to wikipedia the energy density of compressed air is on par with lead-acid batteries. There are some disadvantages, like batteries release their energy at a more constant rate than pressure vessels. There are some advantages, that pressure vessels can discharge their energy faster, which can be good for applications like vehicles where you might want to accelerate quickly.
posted by rustcrumb at 5:46 PM on September 24, 2014
Batteries are a terrible choice: it takes immense amounts of batteries (made of lead or other more noxious things) to store enough energy to make any difference at all to the power grid. Furthermore, a lot of the power used to charge the batteries is turned into heat and doesn't come back when the batteries are discharged.
But I can't say I'm certain this is any better. I can see a lot of potential problems, some of which would be catastrophic but which can't be tested for before the fact. Just how much pressure are they going to put into this chamber? What will it rupture?
As far as I know, the best energy storage technology available now for buffering the power grid is called "pumped-storage hydro". It works and it isn't unreasonably dangerous. It also isn't unreasonably expensive, especially if you use turbines that can act both as pumps and as generators. The only real problem with it is that it has to be built next to a river or large lake, on top of a neighboring hill. That somewhat limits the potential sites.
posted by Chocolate Pickle at 5:49 PM on September 24, 2014
But I can't say I'm certain this is any better. I can see a lot of potential problems, some of which would be catastrophic but which can't be tested for before the fact. Just how much pressure are they going to put into this chamber? What will it rupture?
As far as I know, the best energy storage technology available now for buffering the power grid is called "pumped-storage hydro". It works and it isn't unreasonably dangerous. It also isn't unreasonably expensive, especially if you use turbines that can act both as pumps and as generators. The only real problem with it is that it has to be built next to a river or large lake, on top of a neighboring hill. That somewhat limits the potential sites.
posted by Chocolate Pickle at 5:49 PM on September 24, 2014
I'm not an expert by any means, but I was under the impression that the bigger the project gets, the less important energy density is, and the more important it is that the energy density stays constant over many charge cycles. Building a bigger pumped storage facility is not going to be as costly as having to replace/re-manufacture all the cells in a battery storage facility every X years.
posted by Grimgrin at 5:50 PM on September 24, 2014 [1 favorite]
posted by Grimgrin at 5:50 PM on September 24, 2014 [1 favorite]
Some days, fleetingly, living in the future is actually pretty cool. I wonder if there's a way to scale this down for the home market? How big a pressure vessel would you need to meet the needs of a household for a day?
posted by ob1quixote at 5:53 PM on September 24, 2014 [1 favorite]
posted by ob1quixote at 5:53 PM on September 24, 2014 [1 favorite]
It might - does! - sound bizarre, but mechanical energy storage is entirely legit and has many advantages. It's also very old - you can think of clockwork as being an example and it scales - the Earth/Moon system is a good example of a very large local installation from which we extract energy by way of tides.
It can be very low maintenance and it is inherently non-polluting in operation (although I do wonder what they did with all the brine).
I would think that this plus renewables has the best chance of being the clean reliable energy source of choice, in the long term.
posted by Devonian at 5:55 PM on September 24, 2014 [4 favorites]
It can be very low maintenance and it is inherently non-polluting in operation (although I do wonder what they did with all the brine).
I would think that this plus renewables has the best chance of being the clean reliable energy source of choice, in the long term.
posted by Devonian at 5:55 PM on September 24, 2014 [4 favorites]
Weird. I have no idea how to feel about this. Climate and energy nerds, I await your instructions on what opinion I should form here!
posted by latkes at 5:56 PM on September 24, 2014
posted by latkes at 5:56 PM on September 24, 2014
Climate and energy nerds, I await your instructions on what opinion I should form here!
It's pretty cool!
posted by officer_fred at 5:57 PM on September 24, 2014 [5 favorites]
It's pretty cool!
posted by officer_fred at 5:57 PM on September 24, 2014 [5 favorites]
Whenever ideas like this come up, a problem in the discussion is always that a lot of people don't really understand the scale of the system. Peak summer load in California is about 40 gigawatts (though if it is really really hot it can go higher than that.
That's 40 billion joules per second.
Lead-acid batteries hold 170,000 joules per kilogram.
So it would take 235 metric tonnes of lead-acid batteries to supply California for one second at peak power consumption.
It would take 847 thousand metric tonnes of lead-acid batteries to supply California for one hour at peak consumption. I don't think there is that much lead available on the surface of the earth.
posted by Chocolate Pickle at 5:59 PM on September 24, 2014 [17 favorites]
That's 40 billion joules per second.
Lead-acid batteries hold 170,000 joules per kilogram.
So it would take 235 metric tonnes of lead-acid batteries to supply California for one second at peak power consumption.
It would take 847 thousand metric tonnes of lead-acid batteries to supply California for one hour at peak consumption. I don't think there is that much lead available on the surface of the earth.
posted by Chocolate Pickle at 5:59 PM on September 24, 2014 [17 favorites]
So whenever there is a heat wave in California and people are suddenly cranking up their ACs and spiking demand for power then the people living in Utah will suddenly hear this massive grumbling fart noise rise from beneath their feet as the air battery deflates?
posted by Hairy Lobster at 6:00 PM on September 24, 2014 [24 favorites]
posted by Hairy Lobster at 6:00 PM on September 24, 2014 [24 favorites]
...I was under the impression that the bigger the project gets, the less important energy density is...
It depends on the storage technology. If it's batteries (or super-capacitors) the density definitely matters because it controls the cost per megajoule. And there really isn't any significant economy of scale.
posted by Chocolate Pickle at 6:03 PM on September 24, 2014 [1 favorite]
It depends on the storage technology. If it's batteries (or super-capacitors) the density definitely matters because it controls the cost per megajoule. And there really isn't any significant economy of scale.
posted by Chocolate Pickle at 6:03 PM on September 24, 2014 [1 favorite]
... will bring wind energy from Wyoming to customers in California.
I like to imagine that they build giant funnels in Wyoming that redirect wind into loooong tunnels, storing up the air pressure in the salt dome in Utah. Then, they have more looooong tunnels that can release some of that pressure out in California, blowing directly on wind turbines there to generate electricity.
posted by whatnotever at 6:05 PM on September 24, 2014 [5 favorites]
I like to imagine that they build giant funnels in Wyoming that redirect wind into loooong tunnels, storing up the air pressure in the salt dome in Utah. Then, they have more looooong tunnels that can release some of that pressure out in California, blowing directly on wind turbines there to generate electricity.
posted by whatnotever at 6:05 PM on September 24, 2014 [5 favorites]
Considering that there are only about 50 feet of water over the highest intake for the Hoover Dam, I'm really happy to hear that we're starting to get into Jules Verne territory with renewables because it really seems necessary.
posted by feloniousmonk at 6:10 PM on September 24, 2014 [2 favorites]
posted by feloniousmonk at 6:10 PM on September 24, 2014 [2 favorites]
There are some advantages, that pressure vessels can discharge their energy faster, which can be good for applications like vehicles where you might want to accelerate quickly.
And there are some disadvantages, that pressure vessels can discharge their energy faster, making them either rockets or bombs, depending on how omnidirectional the discharge is. Compressed gas bottles are dangerous if mishandled.
They're saying they have a volume of 19 million cubic feet of storage, and they'll store at 1100psig. That's roughly a 165 foot radius sphere. Surface area is roughly 342,000 square feet, or just over 49 million square inches. At 1100psig, that's just under 54 billion pounds force of total force on the entire cavern, or 238 giganetwons total force.
That is, to use a very precise scientific term, an imperial fuckton of force, and if there's a fracture...wow.
I'd be afraid to be near the damn thing. I can't even find a decent analogy for giganewtons. The Saturn 5 had 35MN or .035GN, of force, so you're looking at, err, close to 7000 Saturn-V at liftoff?
Yeah, that's not a useful analogy. Hmm. 1kg sitting on the ground exerts 9.8N of force, we'll call it 10N because math. So, 23.8 billion kilograms sitting on the ground? That's like 4 Great Pyramids of Giza.
Is that right? I must have slipped an order of magnitude there someone, that's just stupid levels of force. Imperial Fuckton.
posted by eriko at 6:11 PM on September 24, 2014 [11 favorites]
And there are some disadvantages, that pressure vessels can discharge their energy faster, making them either rockets or bombs, depending on how omnidirectional the discharge is. Compressed gas bottles are dangerous if mishandled.
They're saying they have a volume of 19 million cubic feet of storage, and they'll store at 1100psig. That's roughly a 165 foot radius sphere. Surface area is roughly 342,000 square feet, or just over 49 million square inches. At 1100psig, that's just under 54 billion pounds force of total force on the entire cavern, or 238 giganetwons total force.
That is, to use a very precise scientific term, an imperial fuckton of force, and if there's a fracture...wow.
I'd be afraid to be near the damn thing. I can't even find a decent analogy for giganewtons. The Saturn 5 had 35MN or .035GN, of force, so you're looking at, err, close to 7000 Saturn-V at liftoff?
Yeah, that's not a useful analogy. Hmm. 1kg sitting on the ground exerts 9.8N of force, we'll call it 10N because math. So, 23.8 billion kilograms sitting on the ground? That's like 4 Great Pyramids of Giza.
Is that right? I must have slipped an order of magnitude there someone, that's just stupid levels of force. Imperial Fuckton.
posted by eriko at 6:11 PM on September 24, 2014 [11 favorites]
This article sent me scurrying off to read about pumped-storage hydroelectric generators. One of the larger ones in the UK - Dinorwig in Wales, about 1.7GW - was built (by hollowing out a mountain, hell yeah) in order to help the then-planned UK generation system of mostly nuclear plant. Nukes have the characteristic that you really want to leave them running as turning them on and off doesn't save you much but is jolly inconvenient. So your system is often running at over- or under-capacity.
Having a nice big storage system to soak up the one to help with the other is a really good idea.
As it transpired, the nuclear option became less attractive as time went on. So now, the thinking is that the same storage system will be useful for renewables, because of their extreme variability.
Which is ironic in at least two dimensions, but probably goes to show how flexible the basic idea is.
(It's also useful for cold-starting the entire grid, if you've had to turn everything off. I don't like thinking about that too much.)
posted by Devonian at 6:18 PM on September 24, 2014 [1 favorite]
Having a nice big storage system to soak up the one to help with the other is a really good idea.
As it transpired, the nuclear option became less attractive as time went on. So now, the thinking is that the same storage system will be useful for renewables, because of their extreme variability.
Which is ironic in at least two dimensions, but probably goes to show how flexible the basic idea is.
(It's also useful for cold-starting the entire grid, if you've had to turn everything off. I don't like thinking about that too much.)
posted by Devonian at 6:18 PM on September 24, 2014 [1 favorite]
How deep below the surface is this?
Presumably the weight of the rock above the cave is more than capable of withstanding that pressure and the weakest points will really be any valves/doors along any access tunnel/pipe connecting the caves to the surface.
posted by Hairy Lobster at 6:20 PM on September 24, 2014 [2 favorites]
Presumably the weight of the rock above the cave is more than capable of withstanding that pressure and the weakest points will really be any valves/doors along any access tunnel/pipe connecting the caves to the surface.
posted by Hairy Lobster at 6:20 PM on September 24, 2014 [2 favorites]
I'll Zazzle the first Whoopee Cushion attachment for PowerCo's holiday party.
That is all. Wait! No.
Potato gun attachment for the late shift? How far will an Imperial Fuckton of force project your average Idaho? Texas? That would be cool.
posted by sfts2 at 6:24 PM on September 24, 2014 [3 favorites]
That is all. Wait! No.
Potato gun attachment for the late shift? How far will an Imperial Fuckton of force project your average Idaho? Texas? That would be cool.
posted by sfts2 at 6:24 PM on September 24, 2014 [3 favorites]
This is probably a waste of money. If Wyoming had a huge store of electricity from wind it could build greenhouses and heat them and light them and turn their vast acreage into a massive chain of organic farms, using all the power they could possible generate. They have the water too, and they don't need many more people to do this. This might be required in the future regardless. Alternatively, they could build industries that use a lot of electricity and offer a competitive advantage.
posted by Brian B. at 6:36 PM on September 24, 2014
posted by Brian B. at 6:36 PM on September 24, 2014
I'm sure they have done the math but intuitively, to me, flywheel farms seem so much more reasonable.
Still: neat!!
posted by dirtdirt at 6:39 PM on September 24, 2014
Still: neat!!
posted by dirtdirt at 6:39 PM on September 24, 2014
Batteries are ok for very small systems, like a single home, shed, etc.
Flywheels are ok if you have the dollars for them, and somewhere to bury them (in case of catastrophic failure)... for a few hours storage.
Compressed air is a great way to store energy, but you need to be aware of the temperature issues associated with it... compressing air makes it hot... if you can store it hot, great... but we're talking glowing red hot at any decent pressure... so you use a cooler to get rid of the heat, and perhaps store it in a mass, to restore the heat when you expand it to get the power back out. If you can't supply heat fast enough when you draw it out, everything is going to freeze... and your round-trip efficiency is going to suck.
Compressed air pipelines could deliver amazing amounts of energy for bulk distribution.... and you don't have to worry about phasing, or EMP, eddy currents, etc. You also wouldn't have as much worry about NIMBY if it were buried deep enough.
posted by MikeWarot at 6:55 PM on September 24, 2014 [1 favorite]
Flywheels are ok if you have the dollars for them, and somewhere to bury them (in case of catastrophic failure)... for a few hours storage.
Compressed air is a great way to store energy, but you need to be aware of the temperature issues associated with it... compressing air makes it hot... if you can store it hot, great... but we're talking glowing red hot at any decent pressure... so you use a cooler to get rid of the heat, and perhaps store it in a mass, to restore the heat when you expand it to get the power back out. If you can't supply heat fast enough when you draw it out, everything is going to freeze... and your round-trip efficiency is going to suck.
Compressed air pipelines could deliver amazing amounts of energy for bulk distribution.... and you don't have to worry about phasing, or EMP, eddy currents, etc. You also wouldn't have as much worry about NIMBY if it were buried deep enough.
posted by MikeWarot at 6:55 PM on September 24, 2014 [1 favorite]
So... I'm probably getting this all wrong but according to my calculations:
Anyhow, a depth of a couple of hundred meters doesn't sound unrealistic.
As long as any valves and doors can be rigged to withstand that same pressure.
posted by Hairy Lobster at 6:55 PM on September 24, 2014 [1 favorite]
1100 psi = 7,584,233 PaThe average density of granite in the Earth's crust works out to about:
280 kg/m3Because g is just shy of 10m/s2 a stack of 280 unit cubes of granite would be sufficient to generate an equivalent pressure of ~7.6 Megapascal. You'd probably need less than that because of the internal strength of the rock.
Anyhow, a depth of a couple of hundred meters doesn't sound unrealistic.
As long as any valves and doors can be rigged to withstand that same pressure.
posted by Hairy Lobster at 6:55 PM on September 24, 2014 [1 favorite]
This seems like a pretty cool idea, but in my head it plays out as a Simpsons episode:
Homer: So you mean I can power my home with a big underground balloon?
Venture Capitalist: Your home AND all of California!
H: Hmm... sounds like the type of thing that could explode and blow a hole in our atmosphere. I'll take it!
VC: Great, Mr. Simpson, you'll have unlimited free energy in no time!
H: Woohoo! When is no time?
Venture Capitalist edges toward his car
VC: Ohhh about 2023.
H: Woo... wait, that's a long ways away!
VC: Yeah, uh, well it'll be here before you know it and, uh, let me get something from my car.
Car screeches away. Cut to Gil, forlornly smashing his rickety space elevator.
posted by Turkey Glue at 7:01 PM on September 24, 2014 [5 favorites]
Homer: So you mean I can power my home with a big underground balloon?
Venture Capitalist: Your home AND all of California!
H: Hmm... sounds like the type of thing that could explode and blow a hole in our atmosphere. I'll take it!
VC: Great, Mr. Simpson, you'll have unlimited free energy in no time!
H: Woohoo! When is no time?
Venture Capitalist edges toward his car
VC: Ohhh about 2023.
H: Woo... wait, that's a long ways away!
VC: Yeah, uh, well it'll be here before you know it and, uh, let me get something from my car.
Car screeches away. Cut to Gil, forlornly smashing his rickety space elevator.
posted by Turkey Glue at 7:01 PM on September 24, 2014 [5 favorites]
It would take 847 thousand metric tonnes of lead-acid batteries to supply California for one hour at peak consumption. I don't think there is that much lead available on the surface of the earth.
That's not really that much lead. I read that worldwide total production is around 8 million tonnes per year, so your figure is about 1/10 of 1 year's total lead.
posted by crazy_yeti at 7:11 PM on September 24, 2014
That's not really that much lead. I read that worldwide total production is around 8 million tonnes per year, so your figure is about 1/10 of 1 year's total lead.
posted by crazy_yeti at 7:11 PM on September 24, 2014
"Flywheel power storage systems in production as of 2001 have storage capacities comparable to batteries..."
That isn't remotely high enough to be practical for this application; you're still talking kilotons or megatones of equipment, at titanic cost.
posted by Chocolate Pickle at 7:16 PM on September 24, 2014 [1 favorite]
That isn't remotely high enough to be practical for this application; you're still talking kilotons or megatones of equipment, at titanic cost.
posted by Chocolate Pickle at 7:16 PM on September 24, 2014 [1 favorite]
I screwed up my link above about lead acid batteries. It should have been this: Energy Density
posted by Chocolate Pickle at 7:17 PM on September 24, 2014
posted by Chocolate Pickle at 7:17 PM on September 24, 2014
Which is cheaper: building a car battery over half the size of the empire state building, or an empty space half the size of a building?
Ok, that's not a fair description, because turbines aren't free, etc, but once you have both systems side by side, which one is easier to double the storage capacity - build another empire state battery, or leak more water into a nearby salt deposit? Then figure in regular replacement and recycling costs for the empire state battery, vs geological timescales.
Ok, that's still an unfair simplification, but the bottom line is that I think these futuristic engineering projects are super cool. A+++ Would Kickstart :-)
posted by anonymisc at 7:30 PM on September 24, 2014 [2 favorites]
Ok, that's not a fair description, because turbines aren't free, etc, but once you have both systems side by side, which one is easier to double the storage capacity - build another empire state battery, or leak more water into a nearby salt deposit? Then figure in regular replacement and recycling costs for the empire state battery, vs geological timescales.
Ok, that's still an unfair simplification, but the bottom line is that I think these futuristic engineering projects are super cool. A+++ Would Kickstart :-)
posted by anonymisc at 7:30 PM on September 24, 2014 [2 favorites]
Hairy Lobster: So... I'm probably getting this all wrong but according to my calculations:
I think I fixed it:
Fg = force of gravity
Fg = m * g
g is force of gravity, g = 9.81 m/s^2
m is mass of rock column
m = n * V * d
n = number of 1 m^3 blocks in sample column of granite ceiling, unknown
V = 1 m^3 per block
d = density of granite, d = 280 kg/m^3
Fp = force of pressure
Fp = P * A
P = pressure, p = 7.58x10^6 Pa = 7.58x10^6 kg/(m*s^2)
A = area of base of granite ceiling sample column, A = 1 m^2
Fg = Fp
n * V * d * g = P * A
(n) (1 m^3) (280 kg/m^3)(9.81 m/s^2) = (7.58x10^6)(1 m^2)
n * 2746.8 kg*m/s^2 = 7.58x10^6 kg*m/s^2
n = 2760 blocks high, or 2760 m column thickness
Of course, this ignores the strength of the rock itself, which would be considerable at the thicknesses we're discussing.
posted by JauntyFedora at 7:38 PM on September 24, 2014 [2 favorites]
I think I fixed it:
Fg = force of gravity
Fg = m * g
g is force of gravity, g = 9.81 m/s^2
m is mass of rock column
m = n * V * d
n = number of 1 m^3 blocks in sample column of granite ceiling, unknown
V = 1 m^3 per block
d = density of granite, d = 280 kg/m^3
Fp = force of pressure
Fp = P * A
P = pressure, p = 7.58x10^6 Pa = 7.58x10^6 kg/(m*s^2)
A = area of base of granite ceiling sample column, A = 1 m^2
Fg = Fp
n * V * d * g = P * A
(n) (1 m^3) (280 kg/m^3)(9.81 m/s^2) = (7.58x10^6)(1 m^2)
n * 2746.8 kg*m/s^2 = 7.58x10^6 kg*m/s^2
n = 2760 blocks high, or 2760 m column thickness
Of course, this ignores the strength of the rock itself, which would be considerable at the thicknesses we're discussing.
posted by JauntyFedora at 7:38 PM on September 24, 2014 [2 favorites]
Granite is about 2700kg/m^3.... not 280... so your column would be a lot smaller.
Let me try this...
A water column is 0.0361 PSI/inch of height.... granite would therefor be 2.7 times that, or about 0.0975 psi/inch.
1100 / 0.0975 --> 11,282 inches of granite... or 940 feet.
If you want to be safe and just assume hydrostatic pressure alone... back out the 2.7 and you get 2538 feet... about 1/2 mile.
posted by MikeWarot at 7:52 PM on September 24, 2014 [1 favorite]
Let me try this...
A water column is 0.0361 PSI/inch of height.... granite would therefor be 2.7 times that, or about 0.0975 psi/inch.
1100 / 0.0975 --> 11,282 inches of granite... or 940 feet.
If you want to be safe and just assume hydrostatic pressure alone... back out the 2.7 and you get 2538 feet... about 1/2 mile.
posted by MikeWarot at 7:52 PM on September 24, 2014 [1 favorite]
i read an article awhile back about a simple large-scale energy storage system that appealled to me: electric trains going up and down a hill.
the trains would have magnets aboard (or alternatively, the cars would be wrapped in copper wire, with stationary magnets alongside the track), there would be an overhead hookup to power lines, the locomotives would have electric engines and the boxcars would have heavy rocks. a big train at the top of a hill has a lot of potential energy, and its speed up and down could be precisely controlled as needed. why wouldn't this work?
posted by bruce at 8:03 PM on September 24, 2014
the trains would have magnets aboard (or alternatively, the cars would be wrapped in copper wire, with stationary magnets alongside the track), there would be an overhead hookup to power lines, the locomotives would have electric engines and the boxcars would have heavy rocks. a big train at the top of a hill has a lot of potential energy, and its speed up and down could be precisely controlled as needed. why wouldn't this work?
posted by bruce at 8:03 PM on September 24, 2014
Robotic Sysiphii pushing magnetic boulders up hill all day in coil-wound tunnels, which roll back down and generate energy every night.
posted by jason_steakums at 8:07 PM on September 24, 2014 [2 favorites]
posted by jason_steakums at 8:07 PM on September 24, 2014 [2 favorites]
Bruce, like so many of these hypothetical systems the reason it wouldn't work is that it can't reasonably be scaled up enough to make any difference. Your train as describe simply doesn't store enough energy to be useful.
The system you're describing isn't "large scale".
posted by Chocolate Pickle at 8:09 PM on September 24, 2014 [3 favorites]
The system you're describing isn't "large scale".
posted by Chocolate Pickle at 8:09 PM on September 24, 2014 [3 favorites]
So, let me get this: the future is Jules Verne? (Dons brass goggles.)
posted by SPrintF at 8:21 PM on September 24, 2014 [1 favorite]
posted by SPrintF at 8:21 PM on September 24, 2014 [1 favorite]
That is, to use a very precise scientific term, an imperial fuckton of force, and if there's a fracture...wow.
I have to admit my first thought was "Congratulations! You've invented pneumofracking!"
posted by ROU_Xenophobe at 8:33 PM on September 24, 2014 [1 favorite]
I have to admit my first thought was "Congratulations! You've invented pneumofracking!"
posted by ROU_Xenophobe at 8:33 PM on September 24, 2014 [1 favorite]
tfa fails to mention that they've had a 135 MW operation running since 1991.
posted by sebastienbailard at 9:20 PM on September 24, 2014 [4 favorites]
posted by sebastienbailard at 9:20 PM on September 24, 2014 [4 favorites]
I like to imagine that they build giant funnels in Wyoming that redirect wind into loooong tunnels, storing up the air pressure in the salt dome in Utah. Then, they have more looooong tunnels that can release some of that pressure out in California, blowing directly on wind turbines there to generate electricity.
So the power grid of the future is a series of interconnected... tubes.
posted by notyou at 9:45 PM on September 24, 2014 [2 favorites]
So the power grid of the future is a series of interconnected... tubes.
posted by notyou at 9:45 PM on September 24, 2014 [2 favorites]
crazy_yeti: "That's not really that much lead. I read that worldwide total production is around 8 million tonnes per year, so your figure is about 1/10 of 1 year's total lead."
And the lead is 100% recyclable.
bruce: "the trains would have magnets aboard (or alternatively, the cars would be wrapped in copper wire, with stationary magnets alongside the track), there would be an overhead hookup to power lines, the locomotives would have electric engines and the boxcars would have heavy rocks."
Seems overly complicated. An electric winch/generator and a large lead weight on your train tracks would be both simpler and all the generating equipment would be stationary and in a single place.
posted by Mitheral at 9:56 PM on September 24, 2014
And the lead is 100% recyclable.
bruce: "the trains would have magnets aboard (or alternatively, the cars would be wrapped in copper wire, with stationary magnets alongside the track), there would be an overhead hookup to power lines, the locomotives would have electric engines and the boxcars would have heavy rocks."
Seems overly complicated. An electric winch/generator and a large lead weight on your train tracks would be both simpler and all the generating equipment would be stationary and in a single place.
posted by Mitheral at 9:56 PM on September 24, 2014
Wait, what?? We're storing energy by compressing air in a big subterranean chamber, then getting it back by driving a turbine with escaping air?
As I've mentioned before, yep.
posted by RolandOfEld at 10:07 PM on September 24, 2014 [1 favorite]
As I've mentioned before, yep.
posted by RolandOfEld at 10:07 PM on September 24, 2014 [1 favorite]
An electric winch/generator and a large lead weight on your train tracks would be both simpler and all the generating equipment would be stationary and in a single place.
And hydro pumped storage is even simpler, because the only bearings are in the turbine.
posted by Chocolate Pickle at 10:14 PM on September 24, 2014
And hydro pumped storage is even simpler, because the only bearings are in the turbine.
posted by Chocolate Pickle at 10:14 PM on September 24, 2014
Interestingly enough, just next week at the Paris Motor Show we will get to see a much smaller scale version of using air to store energy: the Peugeot HYbrid Air vehicle.
It is a hybrid that stores power using compressed air, then it returns the power to the wheels directly from the air (no electric motors).
This is not experimental. They will be selling these next year.
posted by eye of newt at 10:43 PM on September 24, 2014 [1 favorite]
It is a hybrid that stores power using compressed air, then it returns the power to the wheels directly from the air (no electric motors).
This is not experimental. They will be selling these next year.
posted by eye of newt at 10:43 PM on September 24, 2014 [1 favorite]
MikeWarot, you got it right. I confirmed with an online calculator.
940' or 286.5m.
Which is close to my calculation of 280m. Which I must have gotten by mistakes canceling each other out since I was already off on the weight of a unit cube of granite. So, yay (sort of).
posted by Hairy Lobster at 11:46 PM on September 24, 2014
940' or 286.5m.
Which is close to my calculation of 280m. Which I must have gotten by mistakes canceling each other out since I was already off on the weight of a unit cube of granite. So, yay (sort of).
posted by Hairy Lobster at 11:46 PM on September 24, 2014
(It's also useful for cold-starting the entire grid, if you've had to turn everything off. I don't like thinking about that too much.)
Even more to fun to think about - even after a recent series of upgrades, the batteries for the remote switching systems are only rated for 72 hours. If you have to black-start the grid after that, you have to do it manually.
posted by atrazine at 2:11 AM on September 25, 2014
Even more to fun to think about - even after a recent series of upgrades, the batteries for the remote switching systems are only rated for 72 hours. If you have to black-start the grid after that, you have to do it manually.
posted by atrazine at 2:11 AM on September 25, 2014
It probably won't matter, atrazine, the Carrington Event will have fried the switch gear anyway.
posted by Devonian at 2:39 AM on September 25, 2014 [1 favorite]
posted by Devonian at 2:39 AM on September 25, 2014 [1 favorite]
I just want my own reactor, installed and maintained without too much trouble or cost, that just sits in my basement and hums away. Screw this ridiculous grid nonsense.
posted by nerdler at 4:49 AM on September 25, 2014 [2 favorites]
posted by nerdler at 4:49 AM on September 25, 2014 [2 favorites]
This article sent me scurrying off to read about pumped-storage hydroelectric generators. One of the larger ones in the UK - Dinorwig in Wales, about 1.7GW - was built (by hollowing out a mountain, hell yeah) in order to help the then-planned UK generation system of mostly nuclear plant.
I did the tour at Dinorwig once (it was a rainy day in Snowdonia and it seemed a better option than the Llanberis Museum of Slate) and from what I could gather it exists primarily so that the National Grid doesn't collapse when millions of people simultaneously put their kettles on during the advert break in Coronation Street.
If you can think of anything more British than a colossal engineering feat largely based around the production of untold umpteen millions of cups of tea I'd like to hear it.
posted by sobarel at 5:20 AM on September 25, 2014 [9 favorites]
I did the tour at Dinorwig once (it was a rainy day in Snowdonia and it seemed a better option than the Llanberis Museum of Slate) and from what I could gather it exists primarily so that the National Grid doesn't collapse when millions of people simultaneously put their kettles on during the advert break in Coronation Street.
If you can think of anything more British than a colossal engineering feat largely based around the production of untold umpteen millions of cups of tea I'd like to hear it.
posted by sobarel at 5:20 AM on September 25, 2014 [9 favorites]
Faraday, Newton and Maxwell - there'a a reason these godfathers of energy were British, you know.
That reason is the cuppa.
posted by Devonian at 5:44 AM on September 25, 2014
That reason is the cuppa.
posted by Devonian at 5:44 AM on September 25, 2014
so that the National Grid doesn't collapse when millions of people simultaneously put their kettles on during the advert break in Coronation Street.
This is one reason California should start with a localized solar energy plan, because their peak loads happen between noon and 6pm. IBM announced a new method this week that looks promising.
posted by Brian B. at 6:18 AM on September 25, 2014 [1 favorite]
This is one reason California should start with a localized solar energy plan, because their peak loads happen between noon and 6pm. IBM announced a new method this week that looks promising.
posted by Brian B. at 6:18 AM on September 25, 2014 [1 favorite]
Looks like we'll have to revise our old local joke "Why is Eastern Idaho so windy? Because Utah sucks" to "Because Utah blows".
posted by popaopee at 6:48 AM on September 25, 2014
posted by popaopee at 6:48 AM on September 25, 2014
> (It's also useful for cold-starting the entire grid, if you've had to turn everything off. I don't like thinking about that too much.)
If you want to have an amusing evening, find a local grid operator, sit them down with a beer, and ask about black starting a grid. This is both their nightmare and their raison d'être. It needs one absolute authority controlling scheduling for a region, and a few generators who have the special facility to start and sync the grid. Bringing a grid back up is a very organic process; the wrong timing could cause a frequency fluctuation, triggering a voltage drop and a current spike which will melt weak parts of the grid. Only once enough of the grid is synched can you slowly bring on consumer circuits.
Much of this dash for storage was triggered by recent US legislation that allowed time-shifted storage of renewable energy to be eligible for additional contract payments. The original ruling is astonishingly dry, but it made wind and solar types very happy.
posted by scruss at 7:35 AM on September 25, 2014 [1 favorite]
If you want to have an amusing evening, find a local grid operator, sit them down with a beer, and ask about black starting a grid. This is both their nightmare and their raison d'être. It needs one absolute authority controlling scheduling for a region, and a few generators who have the special facility to start and sync the grid. Bringing a grid back up is a very organic process; the wrong timing could cause a frequency fluctuation, triggering a voltage drop and a current spike which will melt weak parts of the grid. Only once enough of the grid is synched can you slowly bring on consumer circuits.
Much of this dash for storage was triggered by recent US legislation that allowed time-shifted storage of renewable energy to be eligible for additional contract payments. The original ruling is astonishingly dry, but it made wind and solar types very happy.
posted by scruss at 7:35 AM on September 25, 2014 [1 favorite]
Great thread. The minds of MeFi doing back-of-the-envelope calculations and talking about energy storage methods ... I love it!
posted by freecellwizard at 7:56 AM on September 25, 2014
posted by freecellwizard at 7:56 AM on September 25, 2014
Peak summer load in California is about 40 gigawatts . . . That's 40 billion joules per second.
40 gigawatts?? Good heavens, Marty, that's enough to travel back to 1985 33 times!
posted by The Bellman at 8:58 AM on September 25, 2014
40 gigawatts?? Good heavens, Marty, that's enough to travel back to 1985 33 times!
posted by The Bellman at 8:58 AM on September 25, 2014
bruce: ternatively, the cars would be wrapped in copper wire, with stationary magnets alongside the track), there would be an overhead hookup to power lines, the locomotives would have electric engines and the boxcars would have heavy rocks. a big train at the top of a hill has a lot of potential energy, and its speed up and down could be precisely controlled as needed. why wouldn't this work?What you're describing is a modern hydroelectric dam, with the water replaced by train cars filled with rocks, and the turbines replaced with charged copper wires traveling through stator magnets.
Except: the train's friction is certainly much higher than those of the turbine blades (where the motion is confined to a relatively tiny area, that can be force-lubricated, or even magnetically confined to prevent contact), the losses from inefficient coupling between the train wraps and the magnets would be significant (eddy currents in the train's body, for one), something as simple as driving a car onto the tracks would destroy the system (and even if you encapsulate it all in a tunnel, a rock falling from a cracked ceiling would do the same - while a turbine, again, is confined and more easily "armored"), the system can't benefit from natural forces (rain = more potential energy stored in a dam)...
Basically, this system offers no advantages I can see over hydroelectric generation except freedom of location, and significant disadvantages. Pumping water uphill during excess energy production remains a better "battery".
posted by IAmBroom at 9:31 AM on September 25, 2014 [1 favorite]
Potato gun attachment for the late shift? How far will an Imperial Fuckton of force project your average Idaho? Texas? That would be cool.
Pretty sure shooting a state at Texas constitutes messing with it, and we don't take too kindly to that.
posted by DynamiteToast at 9:31 AM on September 25, 2014 [2 favorites]
Pretty sure shooting a state at Texas constitutes messing with it, and we don't take too kindly to that.
posted by DynamiteToast at 9:31 AM on September 25, 2014 [2 favorites]
nerdler: I just want my own reactor, installed and maintained without too much trouble or cost, that just sits in my basement and hums away. Screw this ridiculous grid nonsense.Hey, we want the same thing! How about I pay you to buy two reactors and keep them in your basement? You won't hear a peep out of me; I promise I'll never even visit!
posted by IAmBroom at 9:33 AM on September 25, 2014 [3 favorites]
Why do I get the feeling that fracking will benefit somehow? ("Hey we were just solutions mining for bulbs down there...") I hope they don't get the lion's share of any funds aimed at these air-storage facilities.
I wonder if this could bring about combined geothermal/geodirectdrive supply routes all over the place.
posted by drowsy at 10:04 AM on September 25, 2014
I wonder if this could bring about combined geothermal/geodirectdrive supply routes all over the place.
posted by drowsy at 10:04 AM on September 25, 2014
That's like 4 Great Pyramids of Giza.
I'll see your Great Pyramids and raise you, literally, one Pyramid Lake, California. After all, what do you do after you've pumped all the water from the West Branch California Aqueduct up into the mountains outside Los Angeles? Why, generate electricity on the way back down, of course!
It obviously can't make up for the pumping cost, but hey, it's something.
posted by TheKevinFlynnEffect at 12:28 PM on September 25, 2014 [1 favorite]
I'll see your Great Pyramids and raise you, literally, one Pyramid Lake, California. After all, what do you do after you've pumped all the water from the West Branch California Aqueduct up into the mountains outside Los Angeles? Why, generate electricity on the way back down, of course!
It obviously can't make up for the pumping cost, but hey, it's something.
posted by TheKevinFlynnEffect at 12:28 PM on September 25, 2014 [1 favorite]
MikeWarot: Granite is about 2700kg/m^3.... not 280... so your column would be a lot smaller.
Haha, that's what I get for not double checking Hairy Lobster's constants. (Or using a common sense check that granite is denser than water.)
posted by JauntyFedora at 3:00 PM on September 25, 2014
Haha, that's what I get for not double checking Hairy Lobster's constants. (Or using a common sense check that granite is denser than water.)
posted by JauntyFedora at 3:00 PM on September 25, 2014
Pumping water uphill during excess energy production remains a better "battery".
Because weight for weight, delivered to where you want it, by far the cheapest natural resource is almost certainly water. Except, if you can use it for the purpose you need it for, air.
posted by ambrosen at 4:43 PM on September 25, 2014 [1 favorite]
Because weight for weight, delivered to where you want it, by far the cheapest natural resource is almost certainly water. Except, if you can use it for the purpose you need it for, air.
posted by ambrosen at 4:43 PM on September 25, 2014 [1 favorite]
sobarel: "it was a rainy day in Snowdonia and it seemed a better option than the Llanberis Museum of Slate"
Oh, I'd heard the Slate museum is actually pretty good.
posted by Chrysostom at 8:27 AM on September 26, 2014
Oh, I'd heard the Slate museum is actually pretty good.
posted by Chrysostom at 8:27 AM on September 26, 2014
I keep threatening to take my kids to the Australian National Wool Museum. "It has many interesting examples of twisted fibre!"
posted by Joe in Australia at 11:03 AM on September 27, 2014
posted by Joe in Australia at 11:03 AM on September 27, 2014
Remember that neighbor I've got who claims to be a time traveler from the distant future? I've not mentioned him much lately, after I told him about fracking he got this weird look on his face, half-haunted, half-amused. He's unsettlingly good at making that face and he's had lots of opportunity to make it lately, so I've just taken to not telling him stuff.
When I told him about this, though, he looked at me and said, "Oh, what possibly could be the consequences of pressurizing huge underground chambers in ways that can't be repaired?" Further questions wouldn't draw him out.
I think he's lying about the time-travel thing. But really, I think everyone should have an ambiguously true friend to issue weirdly specific dire warnings about random things.
posted by JHarris at 12:47 PM on September 27, 2014 [1 favorite]
When I told him about this, though, he looked at me and said, "Oh, what possibly could be the consequences of pressurizing huge underground chambers in ways that can't be repaired?" Further questions wouldn't draw him out.
I think he's lying about the time-travel thing. But really, I think everyone should have an ambiguously true friend to issue weirdly specific dire warnings about random things.
posted by JHarris at 12:47 PM on September 27, 2014 [1 favorite]
obligatory cold fusion link
Didn't see it there. You may want to try this new one instead.
posted by Brian B. at 10:36 AM on October 12, 2014
Didn't see it there. You may want to try this new one instead.
posted by Brian B. at 10:36 AM on October 12, 2014
« Older Farm fantasy camp | The 50 Year Argument Newer »
This thread has been archived and is closed to new comments
posted by The Gaffer at 5:30 PM on September 24, 2014 [5 favorites]