Grid-scale batteries: They’re not just lithium

When size and weight don't matter, lots of other battery chemistries can work.

See full article...

 

[DDopson]

H₂'s not actually unusable for transportation, but there are issues that make it a niche thing. If you want to store it densely, for use in relatively long-distance transportation that needs to refuel fairly quickly for instance, you really need to store it liquefied, which has some issues (cryogenics can be hard). If you want to burn it in a combustion engine, you need a spark, which diesels don't have, and you need a little hydrocarbon fuel mixed with it (10-50% range) to start the engine and sometimes to keep it running; using it in an engine still produces NOx (you're burning something in air), and a little GHG from the hydrocarbon fuel component. Leaves me wondering if it might be better overall to skip the hydrogen separation step and just burn the natural gas (Florida East Coast railroad, for instance, runs LNG-powered locomotives in a 3-car set, with 2 locomotives and a "tender" sandwiched between to carry the LNG). Unless of course you have enough surplus electric power and water to just electrolyze hydrogen on-site (possible in low-use situations like a lightly-used HMU transit line).

Apparently there's concern in the railroad business (recent article in a Trains special issue not yet available online) that fuel cells aren't suitable for high-power line-haul use yet. Not powerful enough to replace a diesel in a size that fits a standard road locomotive, though smaller ones can work in switchers. Battery units with comparable output to diesels exist in road locomotive sizes. Wabtec, for instance, offers one with 7 MWH of Li batteries on board (they're not clear on whether those are LC* or LFP) that operates as a hybrid charging during braking, or can be charged at a depot where it has significant dwell time. Those are horrendously expensive, though, and are only a partial diesel replacement (one or two of the several locomotive units in a consist).

Edit: punctuation is hard...

I'm skeptical of hydrogen in transportation across the board, but if I had to choose, I'd say it's the least unlikely in trains.

The problem with using hydrogen for trains and trucks is the huge gap on cost per mile versus batteries. One of the attractions of electrifying trucks is to save on diesel fueling cost, and hydrogen moves that in the wrong direction, increasing both vehicle cost and fueling cost. For trucks, swappable battery packs could address charging times, although that requires solving some coordination problems (eg, who owns the pack?). Or spending 30 minutes at a fast-charger isn't a deal-breaker given that truckers have to comply with maximum driving hour limitations.

For trains, implementing detachable battery cars is even simpler. This means that the train operator needs to buy enough battery cars to have some driving, some charging, but I expect that to compare favorably to the capex for a hydrogen-based train engine.

Ships are the only weight-tolerant application where the range requirement is long enough to justify something like hydrogen, but the cost premium over burning bunker fuel is enormous, so it's not going to happen by market forces alone. It would have to be mandated, and globally, since most shipping occurs in international waters. This is such an uphill fight, that it's better to solve everything else first.

Planes, which are only 2% of all emissions, don't have any good zero-emission solutions. Only about 5% of all air miles are addressable by electric planes, and for those routes, it's a slam-dunk, but that still leaves the other 95% of air miles where batteries are too heavy to meet the range requirement. Hydrogen planes are possible, in theory, but require a complete redesign of the entire aircraft that's a much bigger change than, eg, the difference between 777 versus a 787. The hydrogen volume competes with interior cabin space and hates to be stored in the wing like we do with jet fuel, which is just awful for the plane's structural considerations. Transitioning to hydrogen planes would make flying significantly more expensive. I suspect that it will eventually prove easier to transition to synfuel production than to change the airliner fleet over to hydrogen. Planes are hard, and only account for 2%, so we'd be wise to focus on accelerating the energy and transport solutions where we have higher leverage. Decarbonizing electricity one year sooner buys decades of additional time to figure out air travel.

The first place we are going to see green hydrogen is in displacing the 100,000,000 tons of grey hydrogen produced every year as a feedstock to the chemicals industry. To win there, we need electrolyzers with lower capex/kW that can operate economically on a ~40% duty cycle, plus continued acceleration of renewables deployment. The market opportunity for low duty-cycle electrolysis grows as the renewables penetration grows, and should green hydrogen ever reach the tipping point versus grey hydrogen, it will create a price floor that enables a higher renewables penetration than when considering the electricity market in isolation. From there, any gas peakers still operating would run with the highest hydrogen percentage supported by their turbine, typically 20%, and there would be a market opportunity for fuel cell peakers that burn 100% green hydrogen at higher efficiency. None of this is guaranteed to happen in any short-term timeframe, but it might not be as far off as it currently seems.

 

[bjn]

That's a big bummer. So what's the next alternative? Go closed cycle and recapture and reuse the carbon out of your own flue gas?

Reduction of iron ore to iron via electrochemistry, no reducing agent needed. It can be done, just not economically yet, also issues around very high temperature electrodes needed.

 

[hpsgrad]

To your last point, sometime in the far future, we will eventually reach a happy medium on the CO2 content of our atmosphere and will need to adjust accordingly. Not planning for this now, while we have the chance, will result in the same big business interests holding us back from change.

You wrote this in response to someone asking why a carbon tax would have to expire. Has anybody, ever, set tax rates with centuries-long time horizons in mind? I don’t know of any examples and certainly all modern taxes get their rates adjusted or are repealed and reinstated on vastly shorter time spans than that.

Why, specifically, should a carbon tax expire? Your answer, ‘the same big business interests holding us back from change’ is at best tautological (because established interests/society powers always work to preserve the status quo) and at worst meaningless hand waving.

 

[vanzandtj]

I'm surprised there's no mention of the liquid metal batteries developed by Prof. Sadoway and Ambri, the company he founded. He specializes in batteries where the cathode, electrolyte, and anode are all liquids that self-separate due to differences in density. The latest is apparently a molten calcium-antimony battery. From the article in Spectrum:

"Ambri’s grid battery costs $180/kWh to $250/kWh depending on size and duration, the company says. But its projected cost is about $21/kWh by 2030, according to a paper Sadoway and colleagues published in October 2021 in the journal Renewable and Sustainable Energy Reviews."

 

[Ozy]

There is tons of research going into solid state hydrogen storage. Fixating on the challenges of storing compressed or liquid H2 is probably focusing on the wrong problems.

 

[lukem]

Ships are the only weight-tolerant application where the range requirement is long enough to justify something like hydrogen, but the cost premium over burning bunker fuel is enormous, so it's not going to happen by market forces alone.

I've seen estimates that 40% of global shipping is moving fossil fuels, so reducing the latter helps as well.

The first place we are going to see green hydrogen is in displacing the 100,000,000 tons of grey hydrogen produced every year as a feedstock to the chemicals industry. To win there, we need electrolyzers with lower capex/kW that can operate economically on a ~40% duty cycle, plus continued acceleration of renewables deployment. The market opportunity for low duty-cycle electrolysis grows as the renewables penetration grows, and should green hydrogen ever reach the tipping point versus grey hydrogen, it will create a price floor that enables a higher renewables penetration than when considering the electricity market in isolation. From there, any gas peakers still operating would run with the highest hydrogen percentage supported by their turbine, typically 20%, and there would be a market opportunity for fuel cell peakers that burn 100% green hydrogen at higher efficiency. None of this is guaranteed to happen in any short-term timeframe, but it might not be as far off as it currently seems.

At ~ 55kWh/kg to electrolyze and compress hydrogen, we'll need ~ 5500 TWh per annum for 100 million tons of hydrogen for existing industrial use. For comparison, the world used 25000 TWh in 2021 (per Wikipedia).

Note that I fully support building renewable electricity, including the capacity to power the electrolyzers for our existing uses of hydrogen, let alone the increased demand for hydrogen for other industrial (non transport / non energy generation) purposes - just mentioning the scale of this.

I'm slightly skeptical of using a mix of hydrogen into existing methane infrastructure - even electrical generation - because I read an analysis that even at 20% hydrogen mix into the methane that the actual emissions reductions were significantly less. (I could be misremembering and that problem is about the wacky proposal to pipe hydrogen into existing fossil methane home supply).

 

[lasertekk]

There isn't even any Cobalt in LiFePO4 battery chemistry. This chemistry can scale to arbitrary size without any problems. There are zero resource bottlenecks. Merely manufacturing bottlenecks.

And no patent roadblocks either, CATL lost those, which is why everyone is going down the iron phosphate path, for stationary storage and EVs.

 

[DDopson]

If you're going to talk about emitting CO2, then we can discuss how your hypothetical hydrogen is being produced, where it's being produced, and then if it's off site, how it's being transported. I already stated in another reply (probably far too short, both in length and attitude) that this is about green hydrogen, as anything else runs contrary to the entire point of reducing CO2.

Here is a nice breakdown of the cost to produce green hydrogen. It's definitely from the point of view of using it for aviation, but many of the arguments (and math) are useful for this discussion.

The long and short of it is that sure, we can use green hydrogen for many things, but it's incredibly expensive and difficult to do it with the quantities we would need for energy generation (or in the context of the article I linked, aviation. Sure, you can make the argument that it's different enough that there's room for a slice of hydrogen, but it's not as good as you're making it out to be). One of the primary reasons for this is that it takes SO MUCH ENERGY just to generate it (again, not cracking methane), let alone transport it and store it. It's so much cheaper to just build out renewables/storage.

There's a reason why that's what is already being done.

Indeed, as my prior post clearly states, the vast majority of the 100,000,000 tons (100 Mt) of hydrogen produced and consumed each year is grey hydrogen produced from natural gas. The point of those numbers was to disprove the idea that "we can't store hydrogen". We clearly can.

There's relatively little green hydrogen production because in most places it's still cheaper to produce hydrogen from natural gas. The total volume in 2023 was <1 Mt. Even so, the green hydrogen market doubled from $3.2-billion in 2021 to $6.5-billion in 2024. Much of this growth is occurring in China, where there's relatively little natural gas for making grey hydrogen, but plentiful solar energy, with China producing and deploying more solar than the rest of the world combined. Per the IEA, China had 1.2 GW of electrolyzers at the end of 2023, half of the global total. Compared to 2023's production of <1 Mt, the forward-looking pipeline for electrolyzer deployment projects includes 1.5 Mt/yr of funded projects, 20 Mt/yr of "later stage" projects, and 17 Mt/yr of "early stage" projects. The key take-away is that there's enough of a market for green hydrogen to get the flywheel spinning on electrolyzer cost learning.

The key tipping point would be green hydrogen becoming cheaper that producing grey hydrogen from natural gas. Which isn't easy. The most likely path by which this would happen is through lower cost electrolyzers paired with raw DC output from co-deployed solar panels. This is similar to the co-deployment advantage for solar+storage where relatively more PV panels can be deployed than inverter capacity, and the surplus DC power used to charge a battery bank that's able to leverage the same inverter bank during its own discharge cycle. The LCoE for US solar deployments, including inverter cost, is $24 / MWhr. If the electrolysis can take second priority to grid demand, meaning that it runs most of the time but can be paused in response to grid stress, then the fair price for it's electricity will be even lower that what the grid pays for solar. For example, at $15/MWhr, an electrolysis system with 68% efficiency spends $0.74/kg for electricity making it potentially competitive with $1 to $3 per kg for grey hydrogen. The electrolyzer capex is the key bottleneck because lower electrolyzer capex both directly reduces green hydrogen cost and enables running at lower duty cycles with cheap unreliable electricity.

Green hydrogen scaling needs to lag renewables scaling, otherwise we are spending renewable electricity to inefficiently produce hydrogen instead of using renewable electricity to replace inefficient fossil fuel combustion. Once our grid is renewables dominated, green hydrogen provides the next best place to spend further renewables scaling.

 

[lasertekk]

Looking at the explosive growth of utility grid storage in just the last 2-3 years, it’s all lithium with a few footnotes pointing to a few non-lithium battery set ups. This is a global trend.

 

[TreeCatKnight]

The problem is that the industrial hydrogen we're discussing isn't being used as a fuel, but as a chemical reagent. We need the hydrogen because we actually just need the hydrogen. Grey or green, the cost is irrelevant unless someone can come up with replacement products that don't need the hydrogen in their synthesis.

Isn't the entire point of this tangent revolving around power generation though? My initial reply absolutely was in response to that aspect. I even state specifically that we can still use hydrogen for other things (ie industrial uses). I think we're speaking past each other here.

To even be tangentially related to the article's content about energy storage, this HAS to be the context.

What the fuck? Are you imagining hydrogen molecules somehow behave differently depending on their source?

Are you replying to someone else? Because I specifically talked about why the cost is different, not molecular size. Cracking methane is a cheap and easy source of hydrogen. Generating it via green electrolysis is the opposite.

Uhm, you expect green hydrogen to be more difficult to store long-term than gray hydrogen?

No, I expect it to be a lot more cost intensive to generate, adding to its total cost. It'll always be difficult and expensive to store, especially long term. This is absolutely a big reason why we're not doing it right now.

Am I speaking in tongues?

 

[TreeCatKnight]

Indeed, as my prior post clearly states, the vast majority of the 100,000,000 tons (100 Mt) of hydrogen produced and consumed each year is grey hydrogen produced from natural gas. The point of those numbers was to disprove the idea that "we can't store hydrogen". We clearly can.

There's relatively little green hydrogen production because in most places it's still cheaper to produce hydrogen from natural gas. The total volume in 2023 was <1 Mt. Even so, the green hydrogen market doubled from $3.2-billion in 2021 to $6.5-billion in 2024. Much of this growth is occurring in China, where there's relatively little natural gas for making grey hydrogen, but plentiful solar energy, with China producing and deploying more solar than the rest of the world combined. Per the IEA, China had 1.2 GW of electrolyzers at the end of 2023, half of the global total. Compared to 2023's production of <1 Mt, the forward-looking pipeline for electrolyzer deployment projects includes 1.5 Mt/yr of funded projects, 20 Mt/yr of "later stage" projects, and 17 Mt/yr of "early stage" projects. The key take-away is that there's enough of a market for green hydrogen to get the flywheel spinning on electrolyzer cost learning.

The key tipping point would be green hydrogen becoming cheaper that producing grey hydrogen from natural gas. Which isn't easy. The most likely path by which this would happen is through lower cost electrolyzers paired with raw DC output from co-deployed solar panels. This is similar to the co-deployment advantage for solar+storage where relatively more PV panels can be deployed than inverter capacity, and the surplus DC power used to charge a battery bank that's able to leverage the same inverter bank during its own discharge cycle. The LCoE for US solar deployments, including inverter cost, is $24 / MWhr. If the electrolysis can take second priority to grid demand, meaning that it runs most of the time but can be paused in response to grid stress, then the fair price for it's electricity will be even lower that what the grid pays for solar. For example, at $15/MWhr, an electrolysis system with 68% efficiency spends $0.74/kg for electricity making it potentially competitive with $1 to $3 per kg for grey hydrogen. The electrolyzer capex is the key bottleneck because lower electrolyzer capex both directly reduces green hydrogen cost and enables running at lower duty cycles with cheap unreliable electricity.

Green hydrogen scaling needs to lag renewables scaling, otherwise we are spending renewable electricity to inefficiently produce hydrogen instead of using renewable electricity to replace inefficient fossil fuel combustion. Once our grid is renewables dominated, green hydrogen provides the next best place to spend further renewables scaling.

That's great, and I know this already exists. That doesn't make it easy or cheap; it's simply necessary.

In the context of power generation and storage, it's not necessary.

Since it's missing that critical parameter, it's just not going to take off. There are far easier solutions, and that's where the money already is.

 

[pixelpusher220]

Is any of this interesting in a home use environment? What I'm imagining is a battery service, where every house has a pad somewhere close by, and battery cubes get delivered when the old one wears out. Quick connect cables, a machine to move the cubes, and recycling at nearby(ish) depot.

Maybe not today, but lots of houses are getting solar installations. Pretty up the cubes so they don't look too industrial, and it'll become one of those things that's /just there/, like omnipresent HVAC appliances on the sides of houses.

For me, a huge future home use 'feature' will be thermal mass batteries used exclusively for home heat. 95% efficient. You can build it right into the building foundation and poof, summer heat is used for winter heating. Takes up zero space (edit: surface anyway) and uses junk sand. At least in colder climates, it significantly reduces the energy usage electric batteries would need to be sized for.

 

[zaco]

Reduction of iron ore to iron via electrochemistry, no reducing agent needed. It can be done, just not economically yet, also issues around very high temperature electrodes needed.

Charge must still be conserved in electrochemistry, where are the electrons to reduce Fe(II/III) coming from?

 

[pixelpusher220]

Another aspect to the hydrogen debate is geologic hydrogen https://www.usgs.gov/news/featured-story/potential-geologic-hydrogen-next-generation-energy

Vast stores, but not all readily accessible. But it's a significant amount to have effectively 'green' hydrogen in that we don't have to 'produce' it like via electrolysis.

 

[DDopson]

At ~ 55kWh/kg to electrolyze and compress hydrogen, we'll need ~ 5500 TWh per annum for 100 million tons of hydrogen for existing industrial use. For comparison, the world used 25000 TWh in 2021 (per Wikipedia).

Yes, it's a huge scaling challenge, effectively adding +20% to the global electricity requirements, although note that EVs will add an even greater amount of demand and will require that electricity to be delivered to a consumer-friendly charging point, versus electrolysis can be located near generation sources.

The upside is that electrolysis systems that can be paused in response to grid stress are a powerful mechanism for managing variability, enabling much higher renewables penetration.

I ran the same grid simulation as before, but added requirement to produce 20 MW worth of green hydrogen for industrial use in addition to the 100 MW worth of constant electricity demand, and with causes the lowest cost solution's gas peaker usage to drop from 15% of all electricity to only 4% (because most long-term variability is handled by modulating hydrogen electrolysis). Even though I've forced the scenario to buy green hydrogen, I haven't changed the equipment cost assumptions: €496/kW for 68% efficient electrolyzers, plus €283/kW for a two-stage compressor, which is still much too expensive for green hydrogen to be cheaper than grey hydrogen, so to manage that, the electrolysis duty cycle is relatively high, 48%.

 

[DDopson]

That's great, and I know this already exists. That doesn't make it easy or cheap; it's simply necessary.

In the context of power generation and storage, it's not necessary.

Since it's missing that critical parameter, it's just not going to take off. There are far easier solutions, and that's where the money already is.

Please do enlighten the class. What's the easier solution you are hand-waiving about?

 

[wagnerrp]

In reality, storing the stuff for any period of time is both incredibly wasteful (hydrogen escapes everything that we try to store it in.

We produce 700 cubic kilometers of hydrogen a year (at STP). But apparently this is impossible, since hydrogen would escape from anything we used to try to contain it.

You are vastly overstating the problem.

And is that green hydrogen? Because I'm willing to bet it's just cracking methane, which runs counter to the entire point of this discussion.

Uhm, you expect green hydrogen to be more difficult to store long-term than gray hydrogen?

This is absolutely a big reason why we're not doing it right now.

Your claim is that hydrogen cannot be stored and distributed in large volume, but you're wrong, because it is being stored and distributed in large volume. It has for the better part of a century. You reject that data as it's "grey hydrogen", but that's wrong, because regardless of the source, it is still evidence of hydrogen being stored and distributed in large volume. Then you go on to repeat your claim that we're not actually doing it, because... doing it with grey hydrogen doesn't count?

Don't get me wrong. I don't believe hydrogen will be used heavily for power generation, except perhaps out of convenience at facilities that are already producing/using it for other purposes. My reasons are because the RTE is only half that of even low performance systems currently in use, and the justification (large energy storage) doesn't make sense unless you're insisting that we work within the power grid as it currently exists. The problem of slow leakage is basically a non-issue.

For a data point, maximum permissible leak rates for hydrogen tanks in mobile applications is 1scc/hr/L. For a 10L bottle at 700bar, that's around 4.4M scc total volume, or decades before the tank is empty. To be clear, the reason that hydrogen leaks are a problem is because leaks in an enclosed room can produce explosive mixtures near the ceiling.

 

[Bondles_9]

Yabut here's the thing: Even if whatever study being quoted is accurate, those figures are irrelevant. Irrelevant that is, if you're also claiming that APG is an existential threat that must be dealt with immediately, and with massive amounts of resources. So no, you can't use LCOS figures and expect to make anything sensible out of them.

What is APG?

If you're talking about global heating, you can deal with it urgently while also wanting to do it as cheaply as possible.

 

[real mikeb_60]

...

Not sure I understand why your utility would not allow you to connect a solar+PV system. As long as it has a proper switch to stop feeding the grid during an outage, there aren't any grounds for them to say no, other than malice. They may say no to net-metering for a system that generates more than your usage?

As part of eliminating net metering entirely, they instituted a "solar+storage" rate for residential systems. There are various tweaks available that provide greater or lesser discounts depending on how much of your battery you'll turn over to utility management. If you have enough battery to run off-grid during evening peak periods, you can get a significant discount on power used at other times. But reading between the various lines these rates are for residences that meet most of their needs from solar - essentially, running the battery as storage for local net metering, not as net power producers, and any surplus power delivered to the grid is paid for at avoided cost (around $0.05/kwh). They apparently figure that if you put in enough solar+storage to cover (annually) up to 110% of your recent total usage, you'll still pay for some power for a month or 2 in midwinter, and perhaps a bit in late summer/fall (a/c is needed well into October these days), much like I do now with Net Metering 1.0.

That's essentially how residential distributed generation is now set up. If you want to generate more power than that, you're treated as a commercial co-generation site with much more complicated requirements for interconnection and utility management, and a lower, variable payment rate at true wholesale (seldom more than $0.04/kwh, and sometimes zero). Plus, your system needs to be fully dispatchable including remote shutdown. This is the category I would put the system you described into, unless it's a large rural property designed for full off-grid operation and larger electrical loads than the average suburban or urban site.

 

[C.M. Allen]

Looking at the explosive growth of utility grid storage in just the last 2-3 years, it’s all lithium with a few footnotes pointing to a few non-lithium battery set ups. This is a global trend.

This is the product of economies of scale -- lithium-battery tech is mass-produced at a scale that dwarfs everything else combined. And this is because it has two major industries driving its production scale -- automotive and consumer electronics. So the economics for lithium battery technologies work in its favor. Further increasing lithium battery production to meet the demands of grid-connected storage is relatively trivial. But for the job of grid-scale storage, lithium isn't really the best tool for the job. It's cheapest only due to economies of scale that other better-suited storage technologies have not been able to achieve. And that's a result of much smaller levels of investment, again, because these alternative technologies do not have the same backing and markets driving their production (nor would they ever be suitable for those kinds of uses due to their weight and size).

 

[Faustius23]

I hope they do work out commercially; but, 35% round trip efficiency, and they need a water supply. Response time is (from memory) around 10 seconds; which is worse than pumped hydro, and means they can’t directly take part in some grid stability services, although their design includes Li-ion batteries as a buffer.

I believe it's 40% round trip for 1/10th the cost based on what they reported to the state of Montana.

Better to capture 40% of an oversupply than to curtail it.

But yes, iron air would have to be part of a multi prong solution.

 

[OrvGull]

I wonder how some of these technologies compare with the giant lead acid batteries that local telcos used so that landline phones remained working even during a power outage.

I also saw flooded NiCads used in industrial settings. Basically nickel cadmium batteries constructed like lead acid batteries, where you could add distilled water to combat evaporation. They were nearly indestructible as long as they weren't allowed to run dry.

 

[paulfdietz]

I just wanted to mention that Hydrogen will NOT be used for metal smelting. We're currently dealing with fallout from unintentionally introduced trace amounts of hydrogen into steel. There is currently a multi-billion dollar campaign by the federal government to inspect and remediate bridges that used T1 steel. The cause for the program was multiple collapses caused by failed critical joints from hydrogen embrittlement of the welds.

DRI (Direct Reduced Iron) already uses hydrogen-rich gas to reduce iron ore to metallic iron. The presence of hydrogen is not a showstopper.

https://en.wikipedia.org/wiki/Direct_reduced_iron

 

[paulfdietz]

Charge must still be conserved in electrochemistry, where are the electrons to reduce Fe(II/III) coming from?

From oxygen ions, which get converted to molecular oxygen.

 

[OrvGull]

Trivia about synchronous condensers:
In theory we could repurpose the generators of decommissioned power plants as synchronous condensers.

I believe some existing hydro installations in the US have set up their generators to be switchable synchronous condensers, but I don't remember which ones.

 

[OrvGull]

Yes, building out terawatts of long distance interconnects is a very costly undertaking, but so was building our existing fuel distribution networks, and so would be hundreds of TWh of storage.

The same environmentalists who argue we need to decarbonize will fight you every step of the way when you try to build a new power line corrodor. So will the people whose land you're going to be crossing.

 

[wagnerrp]

The same environmentalists who argue we need to decarbonize will fight you every step of the way when you try to build a new power line corrodor. So will the people whose land you're going to be crossing.

Any reason you need new corridors? "Can't you just" install taller pylons on the same corridors with a second tier of supports for the HVDC?

NIMBY issues with taller towers? FAA issues with taller towers (can't imagine they'll be tall enough for that to matter)? Inductive coupling issues with parallel lines? Safety issues regarding access to stacked lines? Path length issues since following existing corridors will not be direct?

 

[dio82]

This is the product of economies of scale -- lithium-battery tech is mass-produced at a scale that dwarfs everything else combined. And this is because it has two major industries driving its production scale -- automotive and consumer electronics. So the economics for lithium battery technologies work in its favor. Further increasing lithium battery production to meet the demands of grid-connected storage is relatively trivial. But for the job of grid-scale storage, lithium isn't really the best tool for the job. It's cheapest only due to economies of scale that other better-suited storage technologies have not been able to achieve. And that's a result of much smaller levels of investment, again, because these alternative technologies do not have the same backing and markets driving their production (nor would they ever be suitable for those kinds of uses due to their weight and size).

LiFePO4 batteries have cheap ass inputs. It is just a membrane, plus graphite and the electrolyte. The price is mostly determined by Capex for the factory and labour. The material inputs are a tiny fraction of cost.

 

[OrvGull]

Any reason you need new corridors? "Can't you just" install taller pylons on the same corridors with a second tier of supports for the HVDC?

NIMBY issues with taller towers? FAA issues with taller towers (can't imagine they'll be tall enough for that to matter)? Inductive coupling issues with parallel lines? Safety issues regarding access to stacked lines? Path length issues since following existing corridors will not be direct?

I think you'd need to essentially double the tower height to provide sufficient air gap insulation between lines, but I'm not sure. It could potentially work. Where the Pacific DC Intertie shares a route with other lines it's on its own towers, though.

 

[zaco]

From oxygen ions, which get converted to molecular oxygen.

Oxygen isn’t a reducing agent, it’s very electronegative and isn’t gonna lose an e- to Fe. And iron ore is already an oxide! Typically carbon or hydrogen is used to reduce iron ore (as you mention in your other reply).

I was wondering what the electrochemical reaction the other poster was referring to is.

 

[bjn]

Your claim is that hydrogen cannot be stored and distributed in large volume, but you're wrong, because it is being stored and distributed in large volume. It has for the better part of a century. You reject that data as it's "grey hydrogen", but that's wrong, because regardless of the source, it is still evidence of hydrogen being stored and distributed in large volume. Then you go on to repeat your claim that we're not actually doing it, because... doing it with grey hydrogen doesn't count?

Don't get me wrong. I don't believe hydrogen will be used heavily for power generation, except perhaps out of convenience at facilities that are already producing/using it for other purposes. My reasons are because the RTE is only half that of even low performance systems currently in use, and the justification (large energy storage) doesn't make sense unless you're insisting that we work within the power grid as it currently exists. The problem of slow leakage is basically a non-issue.

For a data point, maximum permissible leak rates for hydrogen tanks in mobile applications is 1scc/hr/L. For a 10L bottle at 700bar, that's around 4.4M scc total volume, or decades before the tank is empty. To be clear, the reason that hydrogen leaks are a problem is because leaks in an enclosed room can produce explosive mixtures near the ceiling.

Is it being store and distributed in large volumes though? The main used for industrial H2 is ammonia to make fertiliser and AIUI the H2 is steam reformed from methane and then immediately turned into ammonia in the same facility, so very short pipes and zero storage. Storing H2 or moving H2 for other purposes is comparatively rare. I’ve searched for the sizes of existing H2 storage facilities and not found a total, as for salt domes and H2, it seems to be all pilot projects and nothing serious.

 

[Kasper Wuyts]

Any reason you need new corridors? "Can't you just" install taller pylons on the same corridors with a second tier of supports for the HVDC?

NIMBY issues with taller towers? FAA issues with taller towers (can't imagine they'll be tall enough for that to matter)? Inductive coupling issues with parallel lines? Safety issues regarding access to stacked lines? Path length issues since following existing corridors will not be direct?

I model transmission towers for a living, and I can tell you that public acceptance is the biggest engineering constraint, even more so than money. (I'm just the 'steel' guy, not the 'electrical guy', so I couldn't speak with authority about any effects related to induction/capacitance)
To just give you an idea how constrained this is: Our main design challenge is to create towers that are narrower and lower in case new pylons need to be built, and to adapt towers in a way the silhouette isn't changed in the case of existing towers. Sometimes, demolishing an 80 year old tower and putting a newer standard design in its place would be more cost effective, but then building permits are needed and this becomes a paperwork mess. So instead we rummage through archives to interpret old designs so we can 1:1 replace damaged or rusted segments. We are designing pylons with insulating crossarms to make the tower more compact. You'd think pylon design would be a 'solved problem' after so many years, yet we keep having to reinvent the wheel to accommodate local government needs.

Replacing an entire corridor with taller pylons is prone to same NIMBYism as just creating an entirely new one.

 

[bjn]

Oxygen isn’t a reducing agent, it’s very electronegative and isn’t gonna lose an e- to Fe. And iron ore is already an oxide! Typically carbon or hydrogen is used to reduce iron ore (as you mention in your other reply).

I was wondering what the electrochemical reaction the other poster was referring to is.

It’s called electrolysis, just like the experiments you did in high school splitting water into H2 and O2, or the technique used to refined aluminium from its ores. Just doing the same with iron ore instead.

https://en.m.wikipedia.org/wiki/Electrolysis

https://worldsteel.org/wp-content/uploads/Fact-sheet-Electrolysis-in-ironmaking.pdf

 

[andygates]

Yes, it's a huge scaling challenge, effectively adding +20% to the global electricity requirements, although note that EVs will add an even greater amount of demand and will require that electricity to be delivered to a consumer-friendly charging point, versus electrolysis can be located near generation sources.

The upside is that electrolysis systems that can be paused in response to grid stress are a powerful mechanism for managing variability, enabling much higher renewables penetration.

I ran the same grid simulation as before, but added requirement to produce 20 MW worth of green hydrogen for industrial use in addition to the 100 MW worth of constant electricity demand, and with causes the lowest cost solution's gas peaker usage to drop from 15% of all electricity to only 4% (because most long-term variability is handled by modulating hydrogen electrolysis). Even though I've forced the scenario to buy green hydrogen, I haven't changed the equipment cost assumptions: €496/kW for 68% efficient electrolyzers, plus €283/kW for a two-stage compressor, which is still much too expensive for green hydrogen to be cheaper than grey hydrogen, so to manage that, the electrolysis duty cycle is relatively high, 48%.

This applies to all the "replace an established process with electrolysis and a clever catalyst" processes being scaled up.

 

[Iguana7250]

lithium kabooom

 

[paulfdietz]

Oxygen isn’t a reducing agent, it’s very electronegative and isn’t gonna lose an e- to Fe. And iron ore is already an oxide! Typically carbon or hydrogen is used to reduce iron ore (as you mention in your other reply).

I was wondering what the electrochemical reaction the other poster was referring to is.

The reaction is driven by externally supplied energy, of course. Isn't that how charging a battery works? Maybe I was misunderstanding what the other person was saying.

 

[mmiller7]

They are NOT way cheaper, the cost of AGM batteries is actually now more than LFP and you can only use a bit over half of an AGMs capacity if you want to get a decent life out of them. As far as calibration, top balancing works just fine for LFP, actually better than bottom balancing, so there's no problem keeping them at 100% SoC.

My problem with "old obsolete" SLA is its high internal resistance, and how you really shouldn't run it to near 0% SoC, even for deep-cycle batteries. High internal resistance means you can't easily put a prolonged high load on it (voltage dips too quickly at lower SoC), and a reduced depth-of-discharge rate means you're actually only able to access 60-70% of the energy available in lead acid.

With LFP batteries being ridiculously cheap these days - and I would say almost on par with SLA per Wh, since you can actually use more of the energy stored - there's no good reason to stay with SLA for indoor use. (Not being able to charge below freezing point is a significant drawback for some applications, I'll concede that)

LFPs can sit at 100% for a prolonged time without degradation (it's not that your SLAs in UPSes are staying good forever either), and a good BMS with a shunt and proper calibration shouldn't have any issues figuring out pack SoC.

Where are these cheap Lithium battery powered products?

For about $100 every 5-ish years I can have the ~700Wh of 24V batteries in my big APC UPS on my home server rack replaced. New, with the inverter/UPS unit and expansion chassis it was only about $400 for everything.

Most stuff I've seen that can support a 200W load for around 3 hours is high dollar power stations approaching $1,000 for LFP battery tech and isn't fast enough to switch over so you STILL need the old school UPS...

 

[mmiller7]

Rather than a Li-Ion UPS, what I would like is a integrated PSU + UPS to avoid going from AC->DC->AC->DC.

Except then you have to maintain a dozen or more batteries and are SOL if the device doesn't support it. Good luck replacing the PSU on something like the Starlink router...and while you can get a separate PSU with backup for a cable modem the ISPs blame "not using the original power supply" when anything goes wrong and won't attempt to fix their stuff. Plus then you have monitors, KVMs, switches, routers, and other gear that all use their own model-specific internal PSUs.

The usual way to avoid multiple conversions for large-scale systems is to do AC -> DC and use HVDC to power all the equipment that can support that...and then AC inverter for the handful of things that can't.

 

[wagnerrp]

The usual way to avoid multiple conversions for large-scale systems is to do AC -> DC and use HVDC to power all the equipment that can support that...and then AC inverter for the handful of things that can't.

How “high voltage” are we talking. Telco (and networking) gear is all 48V, and all the stuff I use is 24V. I did once use a 600V UPS, but that was a very special application to feed an inverter for an induction motor.

 

[afidel]

Where are these cheap Lithium battery powered products?

For about $100 every 5-ish years I can have the ~700Wh of 24V batteries in my big APC UPS on my home server rack replaced. New, with the inverter/UPS unit and expansion chassis it was only about $400 for everything.

Most stuff I've seen that can support a 200W load for around 3 hours is high dollar power stations approaching $1,000 for LFP battery tech and isn't fast enough to switch over so you STILL need the old school UPS...

Nobody mentioned a turnkey UPS, but you can buy a 12V 100Ah LFP battery for ~$150 which is cheaper per Wh, and much cheaper per usable Wh. You can get a turnkey 1000/800 UPS for $150 but it only has a 230Wh battery, I guess high runtime LFP UPS isn't a market niche anyone has bothered filling yet.