One step closer to the hydrogen economy
June 28, 2015 4:17 PM Subscribe
...ironic, but fantastic news! He says, trying not to derail things right off the bat. Great news all around, well done, SCIENCE!!, etc.
posted by scrump at 4:24 PM on June 28, 2015 [1 favorite]
posted by scrump at 4:24 PM on June 28, 2015 [1 favorite]
Is the 82% efficiency referred to in the article an EROEI calculation -- the ratio between some measure of the power potential of the hydrogen produced and the equivalent power measure of the electricity used in the electrolysis? Or something else?
posted by MattD at 4:24 PM on June 28, 2015
posted by MattD at 4:24 PM on June 28, 2015
one weird trick!
posted by BungaDunga at 4:27 PM on June 28, 2015 [5 favorites]
posted by BungaDunga at 4:27 PM on June 28, 2015 [5 favorites]
Associate Professor Yi Cui tackles another problem in his spare time: air pollution. He and his students have developed a cheap effective material for air filters that could be used in face masks or window screens. Cui jokes that "It might be the first time in years that people in Beijing can open their window and let in a fresh breeze."
posted by Quietgal at 4:28 PM on June 28, 2015 [5 favorites]
posted by Quietgal at 4:28 PM on June 28, 2015 [5 favorites]
So like, the idea ISN'T that you'd burn the split H or O for your fuel, right? You'd let them bond back together and get a bit of energy from that? The alternative seems to be burning them while they're on the electrodes (a process that consumes electrodes) or else somehow getting the gaseous hydrogen into a jar on its own without blowing things up.
I'm not so great at chemistry.
posted by LogicalDash at 4:30 PM on June 28, 2015
I'm not so great at chemistry.
posted by LogicalDash at 4:30 PM on June 28, 2015
or else somehow getting the gaseous hydrogen into a jar on its own without blowing things up.
Hydrogen floats, so it's easy enough to separate. Here's a how-to.
posted by BungaDunga at 4:40 PM on June 28, 2015
Hydrogen floats, so it's easy enough to separate. Here's a how-to.
posted by BungaDunga at 4:40 PM on June 28, 2015
Is the 82% efficiency referred to in the article an EROEI calculation -- the ratio between some measure of the power potential of the hydrogen produced and the equivalent power measure of the electricity used in the electrolysis? Or something else?
I could be wrong, but I think the efficiency cited there refers just to how much of the energy put into the device can act directly on the process of separating hydrogen and oxygen. C.f. the following paragraph:
"We built a conventional water splitter with two benchmark catalysts, one platinum and one iridium," Wang said. "At first the device only needed 1.56 volts of electricity to split water, but within 30 hours we had to increase the voltage nearly 40 percent. That's a significant loss of efficiency."
So I think what this tells us about water-splitting is that differing materials and device construction make it possible to do the same thing with differing amounts of energy. And this is explained even further:
To find catalytic material suitable for both electrodes, the Stanford team borrowed a technique used in battery research called lithium-induced electrochemical tuning. The idea is to use lithium ions to chemically break the metal oxide catalyst into smaller and smaller pieces.
"Breaking down metal oxide into tiny particles increases its surface area and exposes lots of ultra-small, interconnected grain boundaries that become active sites for the water-splitting catalytic reaction," Cui said. "This process creates tiny particles that are strongly connected, so the catalyst has very good electrical conductivity and stability."
posted by clockzero at 4:48 PM on June 28, 2015
I could be wrong, but I think the efficiency cited there refers just to how much of the energy put into the device can act directly on the process of separating hydrogen and oxygen. C.f. the following paragraph:
"We built a conventional water splitter with two benchmark catalysts, one platinum and one iridium," Wang said. "At first the device only needed 1.56 volts of electricity to split water, but within 30 hours we had to increase the voltage nearly 40 percent. That's a significant loss of efficiency."
So I think what this tells us about water-splitting is that differing materials and device construction make it possible to do the same thing with differing amounts of energy. And this is explained even further:
To find catalytic material suitable for both electrodes, the Stanford team borrowed a technique used in battery research called lithium-induced electrochemical tuning. The idea is to use lithium ions to chemically break the metal oxide catalyst into smaller and smaller pieces.
"Breaking down metal oxide into tiny particles increases its surface area and exposes lots of ultra-small, interconnected grain boundaries that become active sites for the water-splitting catalytic reaction," Cui said. "This process creates tiny particles that are strongly connected, so the catalyst has very good electrical conductivity and stability."
posted by clockzero at 4:48 PM on June 28, 2015
LogicalDash, letting the H and O bond back together is burning. When oxidation happens very fast and produces a lot of heat, we call it burning (combustion), but it's still oxidation.
The idea is indeed to get the hydrogen into a jar and store it for later burning, perhaps in a fuel cell in your car or maybe in a power plant to generate electricity.
posted by Quietgal at 4:53 PM on June 28, 2015 [2 favorites]
The idea is indeed to get the hydrogen into a jar and store it for later burning, perhaps in a fuel cell in your car or maybe in a power plant to generate electricity.
posted by Quietgal at 4:53 PM on June 28, 2015 [2 favorites]
Yeah, will have to read the paper to know what that means. Voltage isn't energy, so I presume there's other stuff about operating currents, but I'd guess that energy measure is how much of the electrical power goes into actually splitting the H2-O bond rather than heating the water or driving other reactions at the electrodes or whatever.
Once you've split the bond, you can recover the energy by recombination later (although not all that energy will be usefully available, depending on the system in which the recombination occurs).
I'd think the major import of this, should it develop into something useful, would be to use hydrogen to store and transport energy from sites where water and electricity are plentiful and cheap without, one hopes, generating CO2 or other unwanted byproducts. But if it's good enough to displace hydrogen-from-hydrocarbon generation, then that's good no matter what you use the hydrogen for.
posted by Devonian at 4:56 PM on June 28, 2015 [1 favorite]
Once you've split the bond, you can recover the energy by recombination later (although not all that energy will be usefully available, depending on the system in which the recombination occurs).
I'd think the major import of this, should it develop into something useful, would be to use hydrogen to store and transport energy from sites where water and electricity are plentiful and cheap without, one hopes, generating CO2 or other unwanted byproducts. But if it's good enough to displace hydrogen-from-hydrocarbon generation, then that's good no matter what you use the hydrogen for.
posted by Devonian at 4:56 PM on June 28, 2015 [1 favorite]
Natural gas does not work on major holidays. Fracking is now obsolete.
posted by mccarty.tim at 4:57 PM on June 28, 2015 [1 favorite]
posted by mccarty.tim at 4:57 PM on June 28, 2015 [1 favorite]
the major import of this would be to use hydrogen to store and transport energy
Very much so, and if it's relatively efficient, it might be part of a system where we build a bunch of solar panels out in the desert and come back later to collect the delicious hydrogen.
Also, this probably isn't the best day to ask him, but what would Elon Musk do?
posted by sneebler at 5:12 PM on June 28, 2015 [2 favorites]
Very much so, and if it's relatively efficient, it might be part of a system where we build a bunch of solar panels out in the desert and come back later to collect the delicious hydrogen.
Also, this probably isn't the best day to ask him, but what would Elon Musk do?
posted by sneebler at 5:12 PM on June 28, 2015 [2 favorites]
Side benefit: submarines do the same thing to make oxygen for the atmosphere. The machines are nicknamed "the bomb" because they make two dangerous gasses with high voltages, in a nasty electrolyte, in a machinery room with other machines leaking oil and diesel fuel. It would be nice if they were a little simpler and maintenance-free.
posted by ctmf at 5:21 PM on June 28, 2015 [3 favorites]
posted by ctmf at 5:21 PM on June 28, 2015 [3 favorites]
So I realize this may be in scale just impractical but would this work with ocean water to assist in desalination or will the water already need to be distilled before the catalyst would be useful.
posted by mrzarquon at 5:22 PM on June 28, 2015 [2 favorites]
posted by mrzarquon at 5:22 PM on June 28, 2015 [2 favorites]
Also, this probably isn't the best day to ask him, but what would Elon Musk do?
Wrap it in a stylish container?
posted by yoink at 5:39 PM on June 28, 2015 [2 favorites]
Wrap it in a stylish container?
posted by yoink at 5:39 PM on June 28, 2015 [2 favorites]
Can someone explain to me what this means fot the swizzle stick industry? I mean it sounds good, but I've been fooled before by Cold Fusion.
posted by any major dude at 5:41 PM on June 28, 2015
posted by any major dude at 5:41 PM on June 28, 2015
Also, this probably isn't the best day to ask him, but what would Elon Musk do?
Probably ask the government for money
posted by clockzero at 6:36 PM on June 28, 2015 [1 favorite]
Probably ask the government for money
posted by clockzero at 6:36 PM on June 28, 2015 [1 favorite]
If this does work, something is missing from the story.
2 H2O plus electricity = 2 H2 and O2
Which gives you the H2 which you burn with O2 to release energy and make water.
There's no way that's going to net you energy in a closed system. Now if you got something like sunlight or bacteria to the work on the first part, then you can win. Otherwise, no.
posted by dances_with_sneetches at 6:36 PM on June 28, 2015 [2 favorites]
2 H2O plus electricity = 2 H2 and O2
Which gives you the H2 which you burn with O2 to release energy and make water.
There's no way that's going to net you energy in a closed system. Now if you got something like sunlight or bacteria to the work on the first part, then you can win. Otherwise, no.
posted by dances_with_sneetches at 6:36 PM on June 28, 2015 [2 favorites]
Trying to electrolyse sea water tends to produce things like chlorine gas, which is rarely a bonus.
posted by Devonian at 6:36 PM on June 28, 2015 [4 favorites]
posted by Devonian at 6:36 PM on June 28, 2015 [4 favorites]
There's no way that's going to net you energy in a closed system.
The question is not does it net energy. The question is, is does it provide an efficient way to convert energy into something storable. Solar, for instance, is weather sensitive and only generates part of the day. You can use it to charge a chemical battery, but the process is not terribly efficient, and batteries discharge even when not in use. Converting to hydrogen could well be a great way to store that energy. (if we can store the hydrogen anyway... About a decade ago there was great hope that metal-organic frameworks might fit that bill, but "about a decade ago" is also around when I switched careers and stopped reading chemistry journals on a regular basis, so...?)
posted by solotoro at 6:51 PM on June 28, 2015 [10 favorites]
The question is not does it net energy. The question is, is does it provide an efficient way to convert energy into something storable. Solar, for instance, is weather sensitive and only generates part of the day. You can use it to charge a chemical battery, but the process is not terribly efficient, and batteries discharge even when not in use. Converting to hydrogen could well be a great way to store that energy. (if we can store the hydrogen anyway... About a decade ago there was great hope that metal-organic frameworks might fit that bill, but "about a decade ago" is also around when I switched careers and stopped reading chemistry journals on a regular basis, so...?)
posted by solotoro at 6:51 PM on June 28, 2015 [10 favorites]
^ and the earth is not a thermodynamically closed system.
posted by HighLife at 6:53 PM on June 28, 2015 [2 favorites]
posted by HighLife at 6:53 PM on June 28, 2015 [2 favorites]
Hmmmm,...is this why there's a sudden rush to build wind turbines around the great lakes? I had assumed it had something to do with on/off shore breeze cycles.
posted by bonobothegreat at 7:04 PM on June 28, 2015
posted by bonobothegreat at 7:04 PM on June 28, 2015
Trying to electrolyse sea water tends to produce things like chlorine gas, which is rarely a bonus.
Unless you use that as a feedstock in other downstream industrial processes, water treatment, etc.
posted by a lungful of dragon at 7:33 PM on June 28, 2015 [2 favorites]
Unless you use that as a feedstock in other downstream industrial processes, water treatment, etc.
posted by a lungful of dragon at 7:33 PM on June 28, 2015 [2 favorites]
If the catalysts get so cheap that you can replace them every week, terrific. Hopefully the nickel will be recoverable from the oxide plates.
I realize it's experimental chemistry, but I get so tired of researchers trumpeting their power density breakthrough then admitting (or omitting) that it will run for just a few days or is nearly impossible to scale up beyond a couple grams.
It's still science worth doing, but it's not a commercial breakthrough.
posted by Kakkerlak at 7:39 PM on June 28, 2015 [1 favorite]
I realize it's experimental chemistry, but I get so tired of researchers trumpeting their power density breakthrough then admitting (or omitting) that it will run for just a few days or is nearly impossible to scale up beyond a couple grams.
It's still science worth doing, but it's not a commercial breakthrough.
posted by Kakkerlak at 7:39 PM on June 28, 2015 [1 favorite]
Being able to efficiently split water to make hydrogen and oxygen would be fantastic for distributing energy and having something nearly as convenient as oil or natural gas. My understanding so far is that yes, you can run a car on hydrogen just like natural gas or petrol, but it's trickier because you have to keep the gas highly pressurised and we also need a way to make lots of it.
Electrolysis of water coupled with solar energy always seemed logical, so something like this that helps make that more efficient and requires less complex engineering and cheaper catalysts helps to improve the economics of hydrogen.
Ignoring the risks of storing high-pressure combustibles, I just got sidetracked thinking about whether a home could make enough energy to fill up a car. I found a source saying gasoline has 32 MJ/L, and a car fuel tank is 50 L, so let's assume we need 1600 MJ as often as you need to fill up your car.
Solar panels apparently produce around 200 W per panel and one can install 25 on a house, for 5 kW of output. If you can get 5 kW for 8 hours a day, then that's 5000 * 8* 3600 J = 144 MJ.
If I'm understanding the 80% efficiency correctly, you can turn the 144 MJ of electrical energy into hydrogen + oxygen that would yield 115 MJ, so you could fill a 1600 MJ tank every two weeks?
I'd love to hear from someone who knows what they're talking about! At this stage I'm guessing we'll need those gas stations for a while longer.
posted by pulposus at 7:57 PM on June 28, 2015
Electrolysis of water coupled with solar energy always seemed logical, so something like this that helps make that more efficient and requires less complex engineering and cheaper catalysts helps to improve the economics of hydrogen.
Ignoring the risks of storing high-pressure combustibles, I just got sidetracked thinking about whether a home could make enough energy to fill up a car. I found a source saying gasoline has 32 MJ/L, and a car fuel tank is 50 L, so let's assume we need 1600 MJ as often as you need to fill up your car.
Solar panels apparently produce around 200 W per panel and one can install 25 on a house, for 5 kW of output. If you can get 5 kW for 8 hours a day, then that's 5000 * 8* 3600 J = 144 MJ.
If I'm understanding the 80% efficiency correctly, you can turn the 144 MJ of electrical energy into hydrogen + oxygen that would yield 115 MJ, so you could fill a 1600 MJ tank every two weeks?
I'd love to hear from someone who knows what they're talking about! At this stage I'm guessing we'll need those gas stations for a while longer.
posted by pulposus at 7:57 PM on June 28, 2015
I can imagine lots of cool techniques if this works commercially. To start with, as others have said, it's a way to store solar energy. I don't know how this compares to battery efficiency, but some home uses are better adapted to combustion than to electricity use: heating and (unintuitively) some forms of cooling, for instance. And the oxygen might be usable, too: you could make a very high-efficiency stove if you fed it with a small, controlled level of compressed oxygen.
posted by Joe in Australia at 8:11 PM on June 28, 2015
posted by Joe in Australia at 8:11 PM on June 28, 2015
stanford university press release obfuscates relevance, importance of mediocre catalyst-improvement paper from stanford research group. news at 11. sigh.
posted by lalochezia at 8:32 PM on June 28, 2015 [2 favorites]
posted by lalochezia at 8:32 PM on June 28, 2015 [2 favorites]
You can use it to charge a chemical battery, but the process is not terribly efficient, and batteries discharge even when not in use.
The lithium battery charge/discharge cycle is much more efficient than the electrolysis/fuel cell hydrogen cycle. Batteries are at like 80-90% efficiency compared to 82% for this new electrolysis technique and 60-ish% or worse for fuel cells. And that's comparing widely available, commodity battery tech with lab numbers for the hydrogen tech.
Remember folks, the hydrogen economy has always been rife with bullshit, and the tech has always sucked compared to good ol' electricity and batteries.
posted by ryanrs at 8:34 PM on June 28, 2015 [4 favorites]
The lithium battery charge/discharge cycle is much more efficient than the electrolysis/fuel cell hydrogen cycle. Batteries are at like 80-90% efficiency compared to 82% for this new electrolysis technique and 60-ish% or worse for fuel cells. And that's comparing widely available, commodity battery tech with lab numbers for the hydrogen tech.
Remember folks, the hydrogen economy has always been rife with bullshit, and the tech has always sucked compared to good ol' electricity and batteries.
posted by ryanrs at 8:34 PM on June 28, 2015 [4 favorites]
Associate Professor Yi Cui tackles another problem in his spare time: air pollution. He and his students have developed a cheap effective material for air filters that could be used in face masks or window screens. Cui jokes that "It might be the first time in years that people in Beijing can open their window and let in a fresh breeze."--Quietgal
The same Yi Cui is working on a potential battery breakthrough.
Who is this guy? A one man fix-the-future superhero?
posted by eye of newt at 9:49 PM on June 28, 2015
The same Yi Cui is working on a potential battery breakthrough.
Who is this guy? A one man fix-the-future superhero?
posted by eye of newt at 9:49 PM on June 28, 2015
That's great! We can use it to fuel our murder machines on the Fury Road.
posted by Halloween Jack at 9:54 PM on June 28, 2015
posted by Halloween Jack at 9:54 PM on June 28, 2015
If I'm understanding the 80% efficiency correctly, you can turn the 144 MJ of electrical energy into hydrogen + oxygen that would yield 115 MJ, so you could fill a 1600 MJ tank every two weeks?--pulposus
Isn't a hydrogen powered electric car (which is what a fuel cell car is), more efficient than a gasoline car? If this is true, perhaps you won't need 1600MJ every two weeks.
posted by eye of newt at 10:10 PM on June 28, 2015
Isn't a hydrogen powered electric car (which is what a fuel cell car is), more efficient than a gasoline car? If this is true, perhaps you won't need 1600MJ every two weeks.
posted by eye of newt at 10:10 PM on June 28, 2015
It seems Yi Cui's group has also developed a faster water purification filter.
posted by eye of newt at 11:50 PM on June 28, 2015
posted by eye of newt at 11:50 PM on June 28, 2015
what would Elon Musk do?
Musk is clear on seeing H2 storage as the issue. Hydrogen's just not weight- or space-efficient as a fuel; batteries store energy better, no?
posted by anadem at 12:11 AM on June 29, 2015
Musk is clear on seeing H2 storage as the issue. Hydrogen's just not weight- or space-efficient as a fuel; batteries store energy better, no?
posted by anadem at 12:11 AM on June 29, 2015
I thought Hydrogen was actually not a great storage medium?
Also, describing this as a fuel "source" is rather misleading, more like a fuel converter. Given that you need to feed in loads of electricity in the first place.
posted by mary8nne at 1:38 AM on June 29, 2015 [1 favorite]
Also, describing this as a fuel "source" is rather misleading, more like a fuel converter. Given that you need to feed in loads of electricity in the first place.
posted by mary8nne at 1:38 AM on June 29, 2015 [1 favorite]
Sorry, yes, voltage is potential energy. It isn't power. The press release used higher voltage as a proxy for less efficiency, and it may well be, but there's not enough information in the press release (bane of my life) to know exactly what that relationship is.
But then, IANA electrochemist. A quick whizz around the Web shows how complicated electrolysis of water into hydrogen and oxygen actually is. Pure water is very hard to electrolyse, because it's a bad conductor (because H2O doesn't have many hydrogen or oxygen ions in it); there's a concept called faradaic efficiency, which I'm pretty sure is what's being referred to here, which says how much energy doesn't go into the main production but is used in side reactions such as producing hydrogen peroxide; there's overpotential, which is how much more voltage you need to apply than the theoretical required; there's a ton more stuff that quickly leads into the wonderlands of catalytic chemistry/physics and thermodynamics and probably quantum phlogistonetics. I half-remember some of this...
In other words, correctly scrying the importance of the announcement cannot be done from the announcement itself, which will be written by the university PR department (where PR means Public Relations and not Peer Review). The paper referred to will probably address enough of the issues to give a much better idea, if you're versed in the area or can spend time getting up to speed. Quicker to ask a chemist who works in the area, and if we're lucky one such will be (a) blogging and (b) not mad. Try to avoid the OMG BRAKETHRU WILL THIS SAVE THE WURLD? sciencey shrieksites...
posted by Devonian at 2:11 AM on June 29, 2015 [3 favorites]
But then, IANA electrochemist. A quick whizz around the Web shows how complicated electrolysis of water into hydrogen and oxygen actually is. Pure water is very hard to electrolyse, because it's a bad conductor (because H2O doesn't have many hydrogen or oxygen ions in it); there's a concept called faradaic efficiency, which I'm pretty sure is what's being referred to here, which says how much energy doesn't go into the main production but is used in side reactions such as producing hydrogen peroxide; there's overpotential, which is how much more voltage you need to apply than the theoretical required; there's a ton more stuff that quickly leads into the wonderlands of catalytic chemistry/physics and thermodynamics and probably quantum phlogistonetics. I half-remember some of this...
In other words, correctly scrying the importance of the announcement cannot be done from the announcement itself, which will be written by the university PR department (where PR means Public Relations and not Peer Review). The paper referred to will probably address enough of the issues to give a much better idea, if you're versed in the area or can spend time getting up to speed. Quicker to ask a chemist who works in the area, and if we're lucky one such will be (a) blogging and (b) not mad. Try to avoid the OMG BRAKETHRU WILL THIS SAVE THE WURLD? sciencey shrieksites...
posted by Devonian at 2:11 AM on June 29, 2015 [3 favorites]
Hydrogen has lousy energy density, high specific impulse, which is why almost everybody uses it for the 2nd stage in orbital boosters, and absolutely no carbon emissions when burned.
That last is the only reason it's worthwhile considering as a transportation fuel, because I can completely refuel a hydrogen car in five minutes, and I cannot completely recharge an electric car with decent range in the same amount of time without dealing with a truly scary amount of current, despite while Elon Musk will tell you (and worse, I can't do it over and over and over and over like I can with a hydrogen station.)
But really, that's the only positive that Hydrogen has in the surface transportation realm. It, like other liquid/gas fuels, can be tanked, thus, it can be transferred quickly. Compared to basically every other one, it's worse in multiple factors, but the big killer is energy density. Hydrogen is not dense. Except in very specific realms, it's not a good choice for storing energy. For getting from, say, 2km/sec to orbital velocity when you're starting at about 5km altitude? There, yes, give me LH2 and LOX, but even there, the density is an issue, and the only thing that turns that around is the fact that you get a specific impulse in vacuum over 450 seconds with LH2, compared to 350 with RP1, and that makes a huge difference when you're trying to turn rocket fuel into spacecraft velocity.
The big problem, to this day, with electric cars, the one that everyone keeps ignoring, is that in the one realm where they are perfect, where 30 miles a day is more than enough 95% of the time and Tesla range is enough 99.99% of the time is the one realm that 80% of the customer base cannot buy them. Dense cities. Why?
BECAUSE THEY DO NOT OWN A PARKING SPACE WITH AN OUTLET!
That's a suburban thing. The posit of the electric car is the garage with an outlet, and the place where you need range is the suburbs. So, there, you need Tesla range, and even then, it gets dicier, and the huge base where you can be selling the easy electric car can't buy because they can't recharge it. (Note that Telsa's other product *ALSO* expects you to have a garage to hang it up on the wall of.)
And suddenly, in a world where you REALLY need to be getting rid of carbon in the atmosphere, and you can't count on being able to plug in an electric car, and the place where car upon car exists is? Then, suddenly, despite the many flaws, hydrogen starts to look like it might work out.
But I don't know. Still -- that zero carbon, hell, zero *anything* bad emission trait is a hell of an argument for H2 as a transport fuel. And, you know, maybe it should cost a lot.
It's *easy* to do electric trains. If we make cars expensive, maybe trains will get popular. But regardless, that's why people continue to look at hydrogen. It is literally the closest thing to the holy grail of true zero emissions. It emits water.
Hell, in California right now, that's negative pollution!
posted by eriko at 3:33 AM on June 29, 2015 [7 favorites]
That last is the only reason it's worthwhile considering as a transportation fuel, because I can completely refuel a hydrogen car in five minutes, and I cannot completely recharge an electric car with decent range in the same amount of time without dealing with a truly scary amount of current, despite while Elon Musk will tell you (and worse, I can't do it over and over and over and over like I can with a hydrogen station.)
But really, that's the only positive that Hydrogen has in the surface transportation realm. It, like other liquid/gas fuels, can be tanked, thus, it can be transferred quickly. Compared to basically every other one, it's worse in multiple factors, but the big killer is energy density. Hydrogen is not dense. Except in very specific realms, it's not a good choice for storing energy. For getting from, say, 2km/sec to orbital velocity when you're starting at about 5km altitude? There, yes, give me LH2 and LOX, but even there, the density is an issue, and the only thing that turns that around is the fact that you get a specific impulse in vacuum over 450 seconds with LH2, compared to 350 with RP1, and that makes a huge difference when you're trying to turn rocket fuel into spacecraft velocity.
The big problem, to this day, with electric cars, the one that everyone keeps ignoring, is that in the one realm where they are perfect, where 30 miles a day is more than enough 95% of the time and Tesla range is enough 99.99% of the time is the one realm that 80% of the customer base cannot buy them. Dense cities. Why?
BECAUSE THEY DO NOT OWN A PARKING SPACE WITH AN OUTLET!
That's a suburban thing. The posit of the electric car is the garage with an outlet, and the place where you need range is the suburbs. So, there, you need Tesla range, and even then, it gets dicier, and the huge base where you can be selling the easy electric car can't buy because they can't recharge it. (Note that Telsa's other product *ALSO* expects you to have a garage to hang it up on the wall of.)
And suddenly, in a world where you REALLY need to be getting rid of carbon in the atmosphere, and you can't count on being able to plug in an electric car, and the place where car upon car exists is? Then, suddenly, despite the many flaws, hydrogen starts to look like it might work out.
But I don't know. Still -- that zero carbon, hell, zero *anything* bad emission trait is a hell of an argument for H2 as a transport fuel. And, you know, maybe it should cost a lot.
It's *easy* to do electric trains. If we make cars expensive, maybe trains will get popular. But regardless, that's why people continue to look at hydrogen. It is literally the closest thing to the holy grail of true zero emissions. It emits water.
Hell, in California right now, that's negative pollution!
posted by eriko at 3:33 AM on June 29, 2015 [7 favorites]
^^ I couldn't agree more on the point about trains. We already have the technology for transportstion thats zero-emissions and compatible with renewables. The only reason you're not riding it to work is that people are used to the luxury of having their own vehicle, and that conversations about energy are often driven by energy companies who -shockingly - aren't really all that interested in drastically reducing the amount of energy the world uses every quarter.
Also I should clarify that when I say "people" I mean primarily the upper middle class. There are loads of poor and working class people in even the most sprawling Southern and Western cities would be thrilled to have a reliable public transit network, since cars are a financial burden, but they're not the ones with the social and political clout to make it happen.
posted by bracems at 3:59 AM on June 29, 2015
Also I should clarify that when I say "people" I mean primarily the upper middle class. There are loads of poor and working class people in even the most sprawling Southern and Western cities would be thrilled to have a reliable public transit network, since cars are a financial burden, but they're not the ones with the social and political clout to make it happen.
posted by bracems at 3:59 AM on June 29, 2015
but they're not the ones with the social and political clout to make it happen
End subsidization of fossil fuels, pass taxes on fuel and automobiles that fund roads, security, etc. as much as possible. The transition may be rough but the clamor for reliable public transport will grow to a point where those with social and political clout can make it happen.
posted by cell divide at 4:03 AM on June 29, 2015 [2 favorites]
End subsidization of fossil fuels, pass taxes on fuel and automobiles that fund roads, security, etc. as much as possible. The transition may be rough but the clamor for reliable public transport will grow to a point where those with social and political clout can make it happen.
posted by cell divide at 4:03 AM on June 29, 2015 [2 favorites]
MetaFilter: probably quantum phlogistonetics.
Sounds like the start of a good Discworld novel…
posted by five fresh fish at 4:29 AM on June 29, 2015
Sounds like the start of a good Discworld novel…
posted by five fresh fish at 4:29 AM on June 29, 2015
But I don't know. Still -- that zero carbon, hell, zero *anything* bad emission trait is a hell of an argument for H2 as a transport fuel.
Just keep in mind that even hydrogen wouldn't be 100% clean. You can still have NOx emissions from combustion in the presence of air that help drive smog formation.
posted by C'est la D.C. at 5:00 AM on June 29, 2015 [1 favorite]
Just keep in mind that even hydrogen wouldn't be 100% clean. You can still have NOx emissions from combustion in the presence of air that help drive smog formation.
posted by C'est la D.C. at 5:00 AM on June 29, 2015 [1 favorite]
Does this make sense as jet fuel, then?
My sense is that *where* you emit carbon matters, so perhaps we should emit less of it at 30,000 ft.
posted by anotherpanacea at 5:38 AM on June 29, 2015
My sense is that *where* you emit carbon matters, so perhaps we should emit less of it at 30,000 ft.
posted by anotherpanacea at 5:38 AM on June 29, 2015
Does this make sense as jet fuel, then?
Nope. The density problem REALLY hurts it as an aircraft fuel, because it takes up so much space that it makes the aircraft uneconomical as a transport for cargo or people.
The reasons hydrocarbon fuels took over was that about the only thing we have that beats them on energy density is nuclear fuel (and, boy howdy, does fissile U or Pu beat them on energy density.) You fill the wings of a 777 with Jet-A, you fly across an ocean. You fill an entire 777 with Hydrogen, I don't think you'd get across the USA, and of course, you're not carrying much -- not because the plane can't handle the mass, but because there's nothing but fuel tanks in the plane.
It even hurts in rockets, which is why burning LH2 in the first stage tends to be suboptimal -- you end up with an enormous tank. Look at the Shuttle's tank. It used LH2 because the SSME's burned the whole way to orbit, and for the 6 minutes they burned in vacuum, they took advantage of the specific impulse, but they paid a huge drag price with that large tank. The Delta IV also pays a drag penalty by using LH2/LOX in the first stage, but not as bad as the Shuttle (it's a vertical stack) -- but it's still the largest launcher flying by a goodly bit, and the non-heavy variant of the Delta IV is just the Heavy without the two side boosters and some smaller solids attached.
I should note that's not a correct drawing of the Falcon 9/9H -- that's the older arrangement of the engines (9 in a square) not the current 1.1 version (8 in a circle, one in the middle.)
posted by eriko at 6:35 AM on June 29, 2015 [1 favorite]
Nope. The density problem REALLY hurts it as an aircraft fuel, because it takes up so much space that it makes the aircraft uneconomical as a transport for cargo or people.
The reasons hydrocarbon fuels took over was that about the only thing we have that beats them on energy density is nuclear fuel (and, boy howdy, does fissile U or Pu beat them on energy density.) You fill the wings of a 777 with Jet-A, you fly across an ocean. You fill an entire 777 with Hydrogen, I don't think you'd get across the USA, and of course, you're not carrying much -- not because the plane can't handle the mass, but because there's nothing but fuel tanks in the plane.
It even hurts in rockets, which is why burning LH2 in the first stage tends to be suboptimal -- you end up with an enormous tank. Look at the Shuttle's tank. It used LH2 because the SSME's burned the whole way to orbit, and for the 6 minutes they burned in vacuum, they took advantage of the specific impulse, but they paid a huge drag price with that large tank. The Delta IV also pays a drag penalty by using LH2/LOX in the first stage, but not as bad as the Shuttle (it's a vertical stack) -- but it's still the largest launcher flying by a goodly bit, and the non-heavy variant of the Delta IV is just the Heavy without the two side boosters and some smaller solids attached.
I should note that's not a correct drawing of the Falcon 9/9H -- that's the older arrangement of the engines (9 in a square) not the current 1.1 version (8 in a circle, one in the middle.)
posted by eriko at 6:35 AM on June 29, 2015 [1 favorite]
Storage smorage, this is great, it brings us just a bit closer to Personal Dirigibles! So much quieter and calmer than those silly jet packs.
posted by sammyo at 7:29 AM on June 29, 2015 [1 favorite]
posted by sammyo at 7:29 AM on June 29, 2015 [1 favorite]
Remember folks, the hydrogen economy has always been rife with bullshit...
As demonstrated in Who Killed the Electric Car?
posted by Kirth Gerson at 7:35 AM on June 29, 2015
As demonstrated in Who Killed the Electric Car?
posted by Kirth Gerson at 7:35 AM on June 29, 2015
Electric cars also have the problem of the life-cycle cost of batteries, which isn't insignificant if they need to swap out 250 or 500 kg of lithium every few years. Tesla is building a manufacturing plant that will double global production. Is there recycling component to that?
Hydrogen is a bitch of a gas to use in many ways---it can even migrate through steel or copper pipes and tanks, everything leaks hydrogen. It's not toxic though, or especially dangerous compared to hydrocarbons, particularly. Hydrogen is quite a bit more difficult to get to explode.
The problem I think hydrogen will solve is one batteries just can't solve: high reserve capacity. There is simply no way right now to have enough storage capacity on an electric grid to run from opportunistic and fluctuating renewable sources like solar and wind. How do you store tens of gigawats for when you need it? Batteries are orders of magnitude away from providing those answers. Hydro pumping is one of the few methods that's large enough, but like hydrogeneration itself, is only possible if you've been blessed with just the right geography (and it's worse than 50% efficient).
A hydrogen generator, tank farm and turbine set-up could probably hit around 40% to 50% storage efficiency and do so for capacities limited only by the number of tanks you can build. But even that beats the 0% storage efficiency we have now with renewable sources. And thus we still need coal, natural gas and nuclear in our current mix. Hydrogen storage might help eliminate the need for conventional base power.
posted by bonehead at 7:56 AM on June 29, 2015 [4 favorites]
Hydrogen is a bitch of a gas to use in many ways---it can even migrate through steel or copper pipes and tanks, everything leaks hydrogen. It's not toxic though, or especially dangerous compared to hydrocarbons, particularly. Hydrogen is quite a bit more difficult to get to explode.
The problem I think hydrogen will solve is one batteries just can't solve: high reserve capacity. There is simply no way right now to have enough storage capacity on an electric grid to run from opportunistic and fluctuating renewable sources like solar and wind. How do you store tens of gigawats for when you need it? Batteries are orders of magnitude away from providing those answers. Hydro pumping is one of the few methods that's large enough, but like hydrogeneration itself, is only possible if you've been blessed with just the right geography (and it's worse than 50% efficient).
A hydrogen generator, tank farm and turbine set-up could probably hit around 40% to 50% storage efficiency and do so for capacities limited only by the number of tanks you can build. But even that beats the 0% storage efficiency we have now with renewable sources. And thus we still need coal, natural gas and nuclear in our current mix. Hydrogen storage might help eliminate the need for conventional base power.
posted by bonehead at 7:56 AM on June 29, 2015 [4 favorites]
There is simply no way right now to have enough storage capacity on an electric grid to run from opportunistic and fluctuating renewable sources like solar and wind.
The fact that both those sources are weather-dependent, and that weather prediction now works as well as it does, means that they're actually rather more predictable - and therefore dispatchable - than most pundits give them credit for.
How do you store tens of gigawatts for when you need it?
Preferably reasonably close to the point of generation (i.e. in the same building as the solar panel, or at the base of the wind turbine tower) so that the round-trip loss in your storage facility doesn't get multiplied by I2R losses in the grid, in modules scaled to match the capacity of your distributed generators so as to take advantage of the economies of scale made possible by mass production.
A hydrogen generator, tank farm and turbine set-up could probably hit around 40% to 50% storage efficiency and do so for capacities limited only by the number of tanks you can build.
Or you can use tanks full of gravel and get better than 70%. Or batteries and get closer to 90% at about twice the price, though battery costs continue to fall even faster than most of the industry has been expecting.
posted by flabdablet at 8:38 AM on June 29, 2015 [1 favorite]
The fact that both those sources are weather-dependent, and that weather prediction now works as well as it does, means that they're actually rather more predictable - and therefore dispatchable - than most pundits give them credit for.
How do you store tens of gigawatts for when you need it?
Preferably reasonably close to the point of generation (i.e. in the same building as the solar panel, or at the base of the wind turbine tower) so that the round-trip loss in your storage facility doesn't get multiplied by I2R losses in the grid, in modules scaled to match the capacity of your distributed generators so as to take advantage of the economies of scale made possible by mass production.
A hydrogen generator, tank farm and turbine set-up could probably hit around 40% to 50% storage efficiency and do so for capacities limited only by the number of tanks you can build.
Or you can use tanks full of gravel and get better than 70%. Or batteries and get closer to 90% at about twice the price, though battery costs continue to fall even faster than most of the industry has been expecting.
posted by flabdablet at 8:38 AM on June 29, 2015 [1 favorite]
j_curiouser: Voltage isn't is energy.
Read your link a little more closely; voltage isn't energy, it's "electric potential energy per unit charge". So it's energy divided by number of electrons. (Or, rather, divided by 6.241×1018 electrons.)
posted by clawsoon at 8:48 AM on June 29, 2015
Read your link a little more closely; voltage isn't energy, it's "electric potential energy per unit charge". So it's energy divided by number of electrons. (Or, rather, divided by 6.241×1018 electrons.)
posted by clawsoon at 8:48 AM on June 29, 2015
Or batteries and get closer to 90% at about twice the price, though battery costs continue to fall even faster than most of the industry has been expecting.
Not possible in our world. There isn't enough battery capacity in the whole world, or the planned or current production capacity available to do this for more than a trivial amount of power needs. We'd need many Gigafactorys producing entirely for the grid for decades to make enough.
It can work at the single house level (and Musk is trying to develop a secondary market there to absorb any possible excess capacity), but he couldn't meet demand for every house built in NA in a year, not even close.
Batteries just are not a practical answer to this problem, not in their current state. Things like the gravel thing too, can you build those on the scale of a water reservoir? Because that's what you need for a city of a million or so.
We know how to build tanks and turbines now. All that's missing is the generation piece. As they're relatively self contained, they could be sited near production in many cases. Wind, in particular is located on coastlines in a lot of the world.
posted by bonehead at 9:50 AM on June 29, 2015
Not possible in our world. There isn't enough battery capacity in the whole world, or the planned or current production capacity available to do this for more than a trivial amount of power needs. We'd need many Gigafactorys producing entirely for the grid for decades to make enough.
It can work at the single house level (and Musk is trying to develop a secondary market there to absorb any possible excess capacity), but he couldn't meet demand for every house built in NA in a year, not even close.
Batteries just are not a practical answer to this problem, not in their current state. Things like the gravel thing too, can you build those on the scale of a water reservoir? Because that's what you need for a city of a million or so.
We know how to build tanks and turbines now. All that's missing is the generation piece. As they're relatively self contained, they could be sited near production in many cases. Wind, in particular is located on coastlines in a lot of the world.
posted by bonehead at 9:50 AM on June 29, 2015
Energy consumption in the US per day was just under 100 quad btu last year. About 20% of that was electric. Call it 20 quad in electricity per year, roughly 16,000 GWhrs per day, if I've done the math right. If you want to buffer 1/2 or 2/3rds of that, you need storage for 8 to 12 thousand GWhrs per day just for the US grid.
The world battery production capacity is about 30 GWhrs per year. The Gigafactory will about double that.
[edit to remove an off by 1000 error. crap]
posted by bonehead at 9:58 AM on June 29, 2015
The world battery production capacity is about 30 GWhrs per year. The Gigafactory will about double that.
[edit to remove an off by 1000 error. crap]
posted by bonehead at 9:58 AM on June 29, 2015
I heard a talk on the radio about use of flywheels for grid-level energy storage, including a big leap forward expected with higher temperature superconducting magnets used in the bearing system to reduce friction to essentially zero.
posted by Rumple at 10:09 AM on June 29, 2015
posted by Rumple at 10:09 AM on June 29, 2015
We'd need many Gigafactorys producing entirely for the grid for decades to make enough.
That seems roughly consistent with the amount of time that would be required to implement a 100% solar and wind grid. Always nice to see two straw men fighting to the death, leaving nothing behind but chaff.
posted by flabdablet at 10:58 AM on June 29, 2015
That seems roughly consistent with the amount of time that would be required to implement a 100% solar and wind grid. Always nice to see two straw men fighting to the death, leaving nothing behind but chaff.
posted by flabdablet at 10:58 AM on June 29, 2015
Why the insistence it has to be one or the other? If a bunch of technologies work, why not use all of them?
Storage is likely going to be multimodal. Transportation is around 30 quad btu a year, and a large chunk of that will have to be battery (unless sythentic fuels get a lot cheaper). But what is needed for a mobile power consumer may not be the best set of tradeoffs (space, mass, sustainability footprint) as a stationary system.
Batteries have a bunch of problems, in terms of LC footprints (lithium supply and mining issues) and just production capacity. Given that they will continue to be in short supply for likely decades to come, why divert them from high value uses, like vehicles? Transportation is about 30% of our current energy budget and all GHG-emitting. For a stationary system, hooked into a grid, you can trade weight for capacity or even efficiency for capacity. Being able to store unused generation capacity now is a win even at lower efficiency.
Muti-modal storage is win-win, not win-lose. This isn't about picking winners and losers but using what we might have most effectively.
posted by bonehead at 11:11 AM on June 29, 2015 [1 favorite]
Storage is likely going to be multimodal. Transportation is around 30 quad btu a year, and a large chunk of that will have to be battery (unless sythentic fuels get a lot cheaper). But what is needed for a mobile power consumer may not be the best set of tradeoffs (space, mass, sustainability footprint) as a stationary system.
Batteries have a bunch of problems, in terms of LC footprints (lithium supply and mining issues) and just production capacity. Given that they will continue to be in short supply for likely decades to come, why divert them from high value uses, like vehicles? Transportation is about 30% of our current energy budget and all GHG-emitting. For a stationary system, hooked into a grid, you can trade weight for capacity or even efficiency for capacity. Being able to store unused generation capacity now is a win even at lower efficiency.
Muti-modal storage is win-win, not win-lose. This isn't about picking winners and losers but using what we might have most effectively.
posted by bonehead at 11:11 AM on June 29, 2015 [1 favorite]
So once all the worlds water has been turned into Hydrogen and Oxygen, what are we supposed to drink?
posted by Lanark at 11:25 AM on June 29, 2015
posted by Lanark at 11:25 AM on June 29, 2015
roughly 16,000 GWhrs per day, if I've done the math right
Total US electricity use for 2014 was 3862472.334 GWh, or 10582.11598 GWh/day.
I take your point that this is several orders of magnitude greater than yearly battery production, but it's a fair bit less than your original number. Also, if Tesla can double today's world battery production with one factory, that says to me that there's plenty of potential production capacity.
I can see no particular reason to assume that storage technologies won't fill the gaps as the proportion of world energy derived from distributed and variable sources continues its inevitable rise.
posted by flabdablet at 11:31 AM on June 29, 2015
Total US electricity use for 2014 was 3862472.334 GWh, or 10582.11598 GWh/day.
I take your point that this is several orders of magnitude greater than yearly battery production, but it's a fair bit less than your original number. Also, if Tesla can double today's world battery production with one factory, that says to me that there's plenty of potential production capacity.
I can see no particular reason to assume that storage technologies won't fill the gaps as the proportion of world energy derived from distributed and variable sources continues its inevitable rise.
posted by flabdablet at 11:31 AM on June 29, 2015
So once all the worlds water has been turned into Hydrogen and Oxygen, what are we supposed to drink?
Fuel cell exhaust.
posted by flabdablet at 11:31 AM on June 29, 2015 [4 favorites]
Fuel cell exhaust.
posted by flabdablet at 11:31 AM on June 29, 2015 [4 favorites]
If batteries win out over hydrogen for medium- and large-scale storage, it won't be lithium-ion batteries. It'll be vanadium redox flow or something else.
This news could mean we're one small step closer to seeing those affordable (i.e. competitive with batteries, not with petrol) hydrogen fuel cell cars that Honda and Toyota keep claiming they're close to producing. If hydrogen from electrolysis becomes something you can easily make at home with low-cost equipment to refuel your car, that makes a big difference.
posted by sfenders at 11:40 AM on June 29, 2015
This news could mean we're one small step closer to seeing those affordable (i.e. competitive with batteries, not with petrol) hydrogen fuel cell cars that Honda and Toyota keep claiming they're close to producing. If hydrogen from electrolysis becomes something you can easily make at home with low-cost equipment to refuel your car, that makes a big difference.
posted by sfenders at 11:40 AM on June 29, 2015
Things like the gravel thing too, can you build those on the scale of a water reservoir?
Yes.
posted by flabdablet at 11:45 AM on June 29, 2015
Yes.
posted by flabdablet at 11:45 AM on June 29, 2015
hydrogen fuel cell cars
make less sense to me than battery cars with replaceable batteries in a range of standard form factors. Roll into a service station, switch out your flat battery for a charged one, roll out.
Yes, Better Place went belly up. But the fundamental idea still strikes me as a good one.
posted by flabdablet at 11:48 AM on June 29, 2015
make less sense to me than battery cars with replaceable batteries in a range of standard form factors. Roll into a service station, switch out your flat battery for a charged one, roll out.
Yes, Better Place went belly up. But the fundamental idea still strikes me as a good one.
posted by flabdablet at 11:48 AM on June 29, 2015
Hydrogen is a lousy idea for cars for many reasons, transportation and storage being the most important. We'd have to create a third independent distribution network after liquid hydrocarbon fuels and electricity. I think what ever comes after petroleum will have to leverage either of those to succeed. Tesla is using the grid (which has capacity issues if you want to replace the transportation sector as a whole).
The other possibility, to my mind is a synthetic liquid hydrocarbon or pseudo-hydrocarbon fuel into either a conventional IC, hybrid or fuel-cell vehicle. First-gen biofuel have generally been a bust---there just isn't enough waste to produce them, and diverting foodstuffs makes no sense economically---but next-gen non-food based biofuels might work. If the synthetic fuel bacterial systems or algae farms ever get off the ground, that could solve transportation needs by growing fuel, even at relatively crappy biological quantum efficiencies. It's hard to imagine planes, trains or cargo ships all running on batteries, but they've all been shown to work on JP-8 biofuel.
posted by bonehead at 12:03 PM on June 29, 2015
The other possibility, to my mind is a synthetic liquid hydrocarbon or pseudo-hydrocarbon fuel into either a conventional IC, hybrid or fuel-cell vehicle. First-gen biofuel have generally been a bust---there just isn't enough waste to produce them, and diverting foodstuffs makes no sense economically---but next-gen non-food based biofuels might work. If the synthetic fuel bacterial systems or algae farms ever get off the ground, that could solve transportation needs by growing fuel, even at relatively crappy biological quantum efficiencies. It's hard to imagine planes, trains or cargo ships all running on batteries, but they've all been shown to work on JP-8 biofuel.
posted by bonehead at 12:03 PM on June 29, 2015
Hydrogen is a lousy idea for cars for many reasons, transportation and storage being the most important. We'd have to create a third independent distribution network after liquid hydrocarbon fuels and electricity.
Third? In my country we already have more than two large and complicated distribution networks for things. Such as natural gas, milk, and IP packets. Storage is a fairly serious disadvantage, but that's true of battery-electric cars too, and they seem to be doing okay. Fuel cell cost is also still very likely an obstacle, until those aforementioned automakers prove they can actually make a profit on them. Just to be complete, the cost of hydrogen is also going to be always higher than that for electricity.
Personally I'd rather have aluminum-air. Come on Phinergy, pls be real.
posted by sfenders at 1:32 PM on June 29, 2015
Third? In my country we already have more than two large and complicated distribution networks for things. Such as natural gas, milk, and IP packets. Storage is a fairly serious disadvantage, but that's true of battery-electric cars too, and they seem to be doing okay. Fuel cell cost is also still very likely an obstacle, until those aforementioned automakers prove they can actually make a profit on them. Just to be complete, the cost of hydrogen is also going to be always higher than that for electricity.
Personally I'd rather have aluminum-air. Come on Phinergy, pls be real.
posted by sfenders at 1:32 PM on June 29, 2015
All y'all complaining about lithium availability haven't even heard about the stupid amounts of platinum in PEM fuel cells.
posted by ryanrs at 5:14 AM on June 30, 2015
posted by ryanrs at 5:14 AM on June 30, 2015
bonehead: " We'd have to create a third independent distribution network after liquid hydrocarbon fuels and electricity."
This isn't actually a problem; it was done here for LPG for cars without much trouble by piggybacking on the gasoline distribution system.
posted by Mitheral at 5:52 AM on July 1, 2015
This isn't actually a problem; it was done here for LPG for cars without much trouble by piggybacking on the gasoline distribution system.
posted by Mitheral at 5:52 AM on July 1, 2015
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