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...

 

[mhalpern]

I agree that pennies are useless, but 8B and 2.5g each only works out to around 20kt/yr, out of 750kt/yr US production.

also zinc has other uses, one in particular is expected to ramp up for a while, between the new ammo for the xm-7 and various AA munitions.

 

[DDopson]

My comment on thermal batteries were for 200 hr, 500 hr cycles. Er, they can hold the heat for 2 to 3 weeks, with only single digit percentages loss in heat. So, sand based, brick based thermal batteries at 300 to 800 °F. For residential usage, it would be like a big A/C condenser sized unit sitting outside your house. Scale it up for bigger buildings.

This should push the use of burning gas for electricity further down, if the primary use for electricity at night is heating that is. If not, Li-ion or other EV type battery has to reduce their leakage rates. Otherwise, hydrogen or related gas is probably it.

Part of this harkens back to my comment about using the right climate inputs. The need for heating during winter will decrease in the future. Someone probably has done the math for it (for every increased degree in average temp, there will x amount of decrease energy needed for heating), and if you model say a +5 °F warmer winter, and you have to wonder if the grid, people would even bother with long term storage. Like average lows in NYC winter won't be below freezing anymore, and average highs could be in the low 50s. Will Manhattan even cool down?

Your water base HVAC system heats and chills water through a heat pump to both heat and chill water? That water is then pumped through the house. Does it use radiators in each room? A heat exchanger with a central air handling system and ducting?

There are companies that sell systems using water as a thermal reservoir, like Harvest energy, but they mostly sell it a carbon reduction technology, where it uses CASIO solar to heat water during the day and use it to heat the house at night. California's heating needs are modest though. If you are in NYC, its fuel mix doesn't really support the sales pitch.

Regarding our HVAC system, there's so much to laugh at.

First, the basics: On the roof, we have a SpacePak LAHP48 heat-pump that's connected to the basement by 1.5 inch copper pipes carrying a water/glycol mix. In the basement, there's a water tank that buffers the heat so that there's some inertia. Then there's three secondary water loops carrying water to the three habitation floors, each of which has a WCSP-4860JV air handler that uses the chilled/heated water to chill or heat the air. That air is drawn in via one big A/C duct similar to what you'd see in a suburban house, but is then fed back to the rooms via small-diameter (2 inch) high-velocity air tubes that can be snaked through the walls and ceilings of a house that was built in 1901, well before A/C was a design consideration. For reasons I don't understand, the air tubes cost $10/ft. We have about 60 individual tubes ranging from 10 to 40 feet long.

Now for the humor (at my suffering)...

We don't own just one heat-pump, we own THREE! The person who installed this system got oversold pretty hard by an incompetent installer who's no longer an approved SpacePak contractor. Each heat-pump is "4 ton", meaning 48,000 BTU/hr of cooling, which exceeds the entire building's peak needs by a factor of two. I use an Emporia energy monitoring kit that I'd highly recommend -- for $50 you some snap inductive sensors around the wires in your breaker box and it reports 5-minute current data to the cloud so you can use their iPhone app to view historical data or to download the raw data as CSV; works well -- and I can look at the current usage for the HVAC circuit and observe that on the hottest days of summer or the coldest days of winter, the heat pump cycles roughly 20 minutes on / 20 minutes off. During that time, watching some temperature sensors I duct-taped to the pipes, I can observe that the water temperature climbs to 120 degrees (or down to 40 in summer), and then shuts off until an opposing set point is reached and then the system switches back on. So the idea that this house needed three of these beasts is just insane. All three connect to the same heat buffer in the basement, and all three units are functional, but we disabled two of them at the breaker. If anybody in the NYC area wants a perfectly functional $10,000 SpacePak heat-pump and can figure out how to get it off of my roof, it's yours. The next $25,000 of debugging and maintenance labor are your problem.

I have a masters degree in EE from MIT, and when the guy we hired to replace the guy we fired couldn't figure out how our system was wired (at $220 / hr for more than a dozen hours with very little concrete progress other than pitching us on installing a brand new system), I had to dust off my (mostly unused) EE debugging skills to figure it out. I understand electricity, but not HVAC standards, so this was first-principles-only brute-force.

For example, there's a silly number of low-voltage control wires running between the basement and the roof and to the other floors with no apparent logic, so I bought a variety pack of kids colored masking tapes and correlated which bundles were which on each end:

Oh, and good luck with the wiring inside the HVAC cabinet:

The manual documents the system's internal wiring with useful descriptors like "Digital Input #7" (not kidding, that one cost me dozens of hours). See the system is run by a generic microcontroller-based software platform that supports HVAC, dishwashers, boilers, and many other seemingly unrelated devices, so it's behavior is at best under-documented, and even if you understand this multi-device platform (like 10 ppl on Earth), to predict its behavior you need to know the values of various configuration registers, such as P104, which controls the alarming behavior of digital input #7, which SpacePak connected to a failure-prone current sensing system, and by poking the buttons on the panel in a very specific order you can enter a "root password" and modify the control registers, cycling through the register sets named by a letter ("P", "K", "H", etc) and then there's about a hundred registers in each set, each holding an 8-bit value from from 0 to 255, and we had to change P104 from 101 to 0 to disable the false positive overcurrent alarms that were shutting the machine off after anywhere between 3 hrs to 3 days of operation. The heat pump's customization of the microcontroller platform isn't documented, so you absolutely have to talk to SpacePak tech support to do anything, and half of the time I'm paying the contractor $220/hr, they are sitting on my roof hold waiting on hold for a support agent to tell them which buttons to press in what order. There's also a special power resistor kit that you can install inline with the 230V supply wires to fix one of the main causes of unreliability -- they will send it to you for free if you ask nicely. It's like a mad science project where you freeze to death until you figure it out.

Eventually, I worked out that the original installer had created the following situation: Each floor had a thermostat connected to that floor's air-handler, and each air-handler controlled one of the three rooftop heat pumps, all three of which fed to the same heat buffer. This meant that if one floor called for cooling while another floor called for heating, then 230V x 28 Amps of heating would enter a deathmatch with 230V x 28 Amps of cooling (the spec says 30 amps, but it really only pulls 28). I think the heating will eventually win by a hair, but both floors would receive middle-temperature air for a long time while the electric meter spins wildly in circles. I had that happen to me on a much smaller HVAC system in a California rental (I lived there 2 years before escaping) and it can do dramatic things for your power bill.

Ultimately, what prevented the power-spiral-of-death from ever happening was that the prior owner had allowed air bubbles to develop in the coolant lines to two of the units such that instead of running they would flash an "FL 1" error code to tell you "low flow rate" (zero flow). Which meant that all floors could receive cooling as long as the middle floor's thermostat was calling for it (causing the one functional heat pump to run, providing double the building's cooling requirement), but if that middle floor didn't feel like cooling, the other floors would just blow warm air. Or if the middle floor wanted heating and the third floor wanted cooling, the third flow would blow heated air, causing that thermostat to call for even more anti-cooling. This was particularly awkward given that we'd divided the building into a two-family house with renters living upstairs.

Wait, can't the circulation pump fix the air-bubble? No, of course not! The pumps in the basement can maintain circulation when the pipe is full, but they don't have the pressure head to be able to force water 50 feet up to the roof when there's no water in the return line. So you need to manually prime the lines when they develop an air pocket like this. You might think that priming a coolant line would be a standard procedure that the contractors would just show up and perform, but none of them could seem to figure it out. Heck, I struggled to even convince them of the root cause. There's no flow sensors or anything like that, only your human deduction, and by manually applying 120V to the circulation pump in the basement, I could hear water rushing for a few seconds until the pump stagnated, and then when I removed power, I could hear the water rushing back down under the force of gravity -- that's the only evidence I had, and while it was conclusive to me, the contractor wasn't convinced, or at minimum wasn't convinced that the problem wouldn't be even better solved by an $18,000 upgrade to change out all of the pumps for SpacePak's preferred brand of circulation pump -- with that guy we were at an impasse over the acceptable financial scale for solving a low-urgency problem on our backup units. With the third contractor, I told them I warrantied the electrical aspects of the system and they were only responsible for fixing the coolant plumbing, which was intimidating to me at the time, but they couldn't figure out how to get the water all the way to the top. They were using a garden hose and a $30 external pump I had purchased from Amazon (the pump thy brought didn't work) to bump up the pressure head, but that still wasn't enough pressure until I told them to "just trust me" and close the valve from the return line to the tank while opening the drainage valve on the return line so that the air pocket could vent, removing a few dozen psi of back-pressure.

Once I understood the system, it was easy to fix the control scheme. The SpacePak heat pump receives commands not by the US standard HVAC control scheme, but by a semantically equivalent scheme where instead of true/false being communicated by a single wire being either 24V or 0V, true/false is communicated by pairs of wires being either shorted or open. So I took the on/off wire pair from all three air-handler systems and connected them in parallel to the one functional heat pump. This way, any one system shorting the wire pair turns on the heat-pump and it's no problem if multiple systems short the wires at the same time. It's just three relays closing in parallel.

I figured out the control scheme by staring at this relay box until it made sense to me:

There's one of those near each air-handler converting the thermostat's US-standard signalling to the equivalent SpacePak control scheme. Now you can see why there's so many different wires running all over the place.

For controlling heating vs cooling, since it's a whole-house decision, I put a light-switch on the third floor with red tape on the top and blue tape on the bottom, and we change that switch exactly twice a year. This works really well because there's several weeks to a few months in the spring and fall where we don't use either heating or cooling, and the upstairs tenants always want to switch modes before we do, so by the time we care, it's always in the right mode. They just text us when they make the switch. Simple. Effective. Not something I want to be automatic. The system has been reliable for over a year now, it just took a lot of work to get there.

Those are only the highlights along the critical path. I also had a lot of red herrings like rewiring the rooftop boost transformers because our 208V being closer to 210V was causing the boosted voltage to very slightly exceed the spec (242V vs an allowable range of 220 to 240), so I thought that might be related to the digital over-current alarms (nope, unrelated). And there was the 35 amp breaker that kept tripping at only 28 amps of current -- to fix that $14 problem, the prior owner was told he'd have to upgrade the entire house from 200 amps to 400 amp service. Coincidentally, I have a few thousand dollars of new, never-been-used breaker boxes and 000 gauge copper wire in my basement for anyone who wants to pick it up.

Thanks for listening, this has been therapeutic.

And when you are thinking about installing thermal batteries into millions of homes, just imagine a bunch of idiots running around with expensive tools they don't understand, unable to figure out whether a pipe has water in it or not. It's the dumbest little things that make this stuff expensive.

 

[DDopson]

Surely, and the implications are that so far 'green hydrogen's' primary application seems to be hydrogen- or green-washing big petroleum.

I'm not willing to accept by fiat that "we'll just do long-term storage (for the winter months) with a hydrogen network". To say its feasibility has been demonstrated (by a 'modeling tool'!) is a huge lift, and there are many, many articles/studies panning the idea. I can cite as many as you like with a simple google search.

Note that I'm not saying it's infeasible, just that feasibility has yet to be demonstrated. Do you have anything in the way of what you consider convincing evidence? Saying that we'll just adapt the old petroleum storage networks doesn't cut it. Or rather, if you want to go that route, you'll have to show me the cost schedules, what they're paying for, and how long it will take. Which, come to think of it, is what you'd have to show me in any case.

Green Hydrogen's primary application is hydrogen? Who are you hoping to convince with these tautological statements?

The #1 application for hydrogen is producing ammonia, which is used in fertilizer and about a billion other things.

The other applications tend to involve chemicals that have a lot of H's in their formula. Funny that.

A small portion of that is hydrogenated vegetable oil in food products, but there's a long list of other molecules that we hydrogenate.

 

[OrvGull]

My comment on thermal batteries were for 200 hr, 500 hr cycles. Er, they can hold the heat for 2 to 3 weeks, with only single digit percentages loss in heat. So, sand based, brick based thermal batteries at 300 to 800 °F. For residential usage, it would be like a big A/C condenser sized unit sitting outside your house. Scale it up for bigger buildings.

This reminds me of the Dover Sun House, which used sodium sulfate as the storage medium. It dedicated a pretty significant amount of interior space to thermal storage. It apparently worked pretty well for the first couple of years, but quickly degraded after that, and eventually had to have an oil burning furnace installed.

 

[m0nckywrench]

And this was after they tapped it in several places to install flaring towers to hasten the burn. Nary a concern from anywhere not in the immediate area.

Hot-tapping pipeline is common.
Burning railroad tank cars can be hot tapped if you find a brave welder!

https://railroads.dot.gov/sites/fra.dot.gov/files/fra_net/3978/DOT-FRA-ORD-92-27.pdf
From page 156 - Set Up the Hot Tap Operation

1. Hold a safety briefing
2. Locate a willing ASME welder certified in the 6G position

Example:

https://www.cbsnews.com/sacramento/news/lincoln-tanker-fire-teetering-on-edge-of-explosion/
"Crews will now siphon off the propane into a manmade ditch that is being dug right now. The propane will then be burned off safely in the "pond". Officials say that will begin about 5:00 this evening."

 

[David Woodward]

My comment on thermal batteries were for 200 hr, 500 hr cycles. Er, they can hold the heat for 2 to 3 weeks, with only single digit percentages loss in heat. So, sand based, brick based thermal batteries at 300 to 800 °F. For residential usage, it would be like a big A/C condenser sized unit sitting outside your house. Scale it up for bigger buildings.

This should push the use of burning gas for electricity further down, if the primary use for electricity at night is heating that is. If not, Li-ion or other EV type battery has to reduce their leakage rates. Otherwise, hydrogen or related gas is probably it.

Part of this harkens back to my comment about using the right climate inputs. The need for heating during winter will decrease in the future. Someone probably has done the math for it (for every increased degree in average temp, there will x amount of decrease energy needed for heating), and if you model say a +5 °F warmer winter, and you have to wonder if the grid, people would even bother with long term storage. Like average lows in NYC winter won't be below freezing anymore, and average highs could be in the low 50s. Will Manhattan even cool down?

Your water base HVAC system heats and chills water through a heat pump to both heat and chill water? That water is then pumped through the house. Does it use radiators in each room? A heat exchanger with a central air handling system and ducting?

There are companies that sell systems using water as a thermal reservoir, like Harvest energy, but they mostly sell it a carbon reduction technology, where it uses CASIO solar to heat water during the day and use it to heat the house at night. California's heating needs are modest though. If you are in NYC, its fuel mix doesn't really support the sales pitch.

Increasing global climate temperature averages does not preclude local weather minimums. More global heat drives more variable weather, including disruptions to polar jet streams.
https://theconversation.com/global-...frequency-and-intensity-of-cold-spells-223153

 

[Walker On Earth]

The idea that we can use geologic storage is entirely non-controversial, because we already do this at mind-boggling scale for natural gas. And there are various chemicals companies, such as Imperial Chemical Industries that stored Hydrogen underground for decades without any apparent issues. And we've found natural reservoirs of hydrogen gas that was geologically contained for millions of years. Disbelieving this reality is pure ignorance.

As my "feasibility proof" (whatever that is), I submit to you the objective reality that (most of us) live in.

Here's a map of the gas storage capacities for the EU countries:
View attachment 91199

The area of each circle is proportional to that country's gas storage capacity and hovering over a country provides the concrete numbers. For Germany, it's 255 TWhrs of gas, which is almost exactly 200 days worth of Germany's full electricity demand. The storage of gas is measured in months, almost in years, and it absolutely dwarfs the most starry-eyed projections for what Lithium-ion could deliver by 2050. Utterly vast scale of energy storage.

Hydrogen is genuinely harder to store than Methane, but so what? There's two "problems" from a storage perspective.

Sigh. Do you really not know how this works? I believe you. There's this thing called 'research' and here are just a few links on the first page of a very cursory google search:

https://www.courthousenews.com/eu-d...n-revolution-need-reality-check-auditors-say/
https://www.sciencedirect.com/science/article/pii/S0306261923019505
https://www.eca.europa.eu/en/news/NEWS-SR-2024-11
https://www.hydrogeninsight.com/pro...y-and-germany-scrapped-by-equinor/2-1-1713642
https://www.hydrogeninsight.com/pro...0-at-current-rate-hydrogen-europe/2-1-1558335
https://rmi.org/insight/the-value-of-green-hydrogen-trade-for-europe/
Let me explain something to you: Research doesn't mean only find favorable articles. Like the one we're discussing now; more than one poster notes that it reads more like a PR release than an objective article. That you think otherwise is ... mind boggling.

No, don't tell me I didn't read your words properly; I've scrolled back and see that you've leveled that accusation at more than a few people. I'll also note that in a previous comment, allowing for two weeks worth of storage makes me 'a shill for nuclear power' yet you're perfectly okay (from your 'model tool', no less) that hydrogen storage has to provide 336 hours of power. !?!?!?!

Since it is impossible to have a productive discussion with you, since you get your back up at the slightest bit of criticism, I won't be reading any comments from you. PLONK!

 

[Walker On Earth]

I've got him on ignore now but I can still see his latest comments. He really doesn't know how to interpret 'hydrogen- or green-washing'? Once again I believe him and once again I see I was wise to take the action that I did: that means 'hydrogen-washing or green-washing'. Obviously.

 

[DDopson]

I've got him on ignore now but I can still see his latest comments. He really don't know how to interpret 'hydrogen- or green-washing'? Once again I believe him and once again I see I was wise to take the action that I did: that means 'hydrogen-washing or green-washing'. Obviously.

Can you please clarify your actual position? You seem to think that I'm wrong, or naive, or that I've insufficiently supported my arguments, but it's not clear what you believe we should do.

• Are you arguing that we should stop using hydrogen industrially? We currently use 100 Mt/yr.
  
  
• Are you arguing that grey hydrogen produced from methane is good enough and we should continue producing that? Until when? Forever?
  
  
• If you are a grey hydrogen proponent, are you arguing for carbon capture, or for releasing the emissions?
  
  
• Is there some other path not listed above?

 

[DDopson]

Let me explain something to you: Research doesn't mean only find favorable articles. Like the one we're discussing now; more than one poster notes that it reads more like a PR release than an objective article. That you think otherwise is ... mind boggling.

That's not an accurate description of my position.

If you'll look on the first page of comments, you'll notice that I'm the first person who expressed skepticism over this article's lack of any quantitative information on expected cost, and many of the other comments you are referring to are in fact responses to my comment. When I was criticized for not doing that research myself, I pointed out that I did look for pricing information, but the companies surveyed in this article seemingly don't release pricing information, only "glossy marketing materials", and then on page 3, I dug up a study showing that sodium sulfer batteries haven't improved at all in the last 40 years, and several other posters dug up additional information on how Vanadium was once thought to maybe have a chance to catch up to where Lithium-ion batteries were at the time. I tried to keep those posts polite and objective, but the data presented was extremely unfavorable to the idea of these technologies ever being anything other than "a once-promising also-ran technology that's getting lapped by the superior scaling economics of the dominant tech path", which is a direct quote from my post on page 3.

Your arguments would carry more weight if you'd accurately represent other people's positions instead of trying to ascribe to them whatever position you'd prefer to attack.

 

[DDopson]

I'll also note that in a previous comment, allowing for two weeks worth of storage makes me 'a shill for nuclear power' yet you're perfectly okay (from your 'model tool', no less) that hydrogen storage has to provide 336 hours of power. !?!?!?!

Hydrogen storage doesn't "have" to provide anything. A zero-emissions grid is possible for slightly more cost by providing 9.5 hours of Lithium-ion storage and 0 hours of Hydrogen storage, along with significantly more generating capacity, heavily curtailed. That grid is still cheaper than a fossil-only grid, but it's +30% more expensive than the lowest cost grid with mostly renewables and a little bit of fossil backup.

There's no one specific requirement for storage capacity independent of the price assumptions and other considerations. You can't say "we need X hrs or we can't possibly have a reliable grid" because that's not how grid optimization works. With enough wind power and transmission capacity, we could create a reliable grid without any storage at all (other than that required to backstop frequency regulation services); it would merely be a lot more expensive to build a grid that way. Adding the right amount of storage saves money and that optimal amount depends intimately on a statistical analysis of generation timing. Storage trades with transmission capacity and with provisioning excess generation capacity. It's impossible to analyze one of these things in isolation from the others.

In that prior thread, you were trying to assert a minimum storage requirement, either months or weeks or any value you could hold other commenters to that would be excessive for Lithium-ion, so that you could multiply by the cost per kWhr for Lithium-ion capacity and "prove" that batteries were a stupid, dumb, useless idea that was obviously never going to work because it wasn't "baseload". We needed "baseload".

It just doesn't work like that. The cost assumptions change, and in response the optimal balance between system components changes. For example, if I change hydrogen storage to stainless tanks that are 100X more expensive than geologic storage, the optimal zero-emissions solution no longer wants hundreds of hours of hydrogen storage because that would be too expensive for too little marginal benefit. But it still wants some hydrogen storage. Increases in capacity are a diminishing returns game. You'd like as much as you can get, but you also want to limit spending. It's an optimization problem where the goal is to discover intuitions about the system dynamics, not a pissing contest over whose technology is prettiest.

 

[paulfdietz]

Green Hydrogen's primary application is hydrogen? Who are you hoping to convince with these tautological statements?

The #1 application for hydrogen is producing ammonia, which is used in fertilizer and about a billion other things.

The other applications tend to involve chemicals that have a lot of H's in their formula. Funny that.

A small portion of that is hydrogenated vegetable oil in food products, but there's a long list of other molecules that we hydrogenate.

There's also hydrodesulfurization of petroleum, but presumably that application goes away in the post-fossil fuel economy.

Hydrodeoxygenation of biomass could be big. See https://virent.com

 

[DDopson]

There's also hydrodesulfurization of petroleum, but presumably that application goes away in the post-fossil fuel economy.

Hydrodeoxygenation of biomass could be big. See https://virent.com

IIUC, hydrodeoxygenation means taking something like fructose:

And then probably getting hydrogen to rip off those OH groups and turn them into an H20 byproduct, leaving you with something that looks a lot like an aromatic hydrocarbon:

Interesting idea, although even if that process works flawlessly, it probably still suffers from the same scaling limits as other biofuels. ie, it's hard to produce as much sugar as we use of gasoline. Plants are really bad at capturing solar energy. Or they can actually capture it with comparable efficiency to a single-junction solar cell, but everything after that is so inefficient that <1% of the energy turns into biomass.

 

[paulfdietz]

Interesting idea, although even if that process works flawlessly, it probably still suffers from the same scaling limits as other biofuels. ie, it's hard to produce as much sugar as we use of gasoline. Plants are really bad at capturing solar energy. Or they can actually capture it with comparable efficiency to a single-junction solar cell, but everything after that is so inefficient that <1% of the energy turns into biomass.

Yes, it has scaling limits. But the idea has some advantages. It's fairly liberal about the feedstock, unlike enzymatic approaches. It's not just sugar it could process, but really any small organic molecules (furans, fragments of lignin). It potentially uses all the carbon in the biomass, not just part (ethanol production turns a good chunk of the carbon in sugars into CO2). Think of it as exploiting plants as carbon collectors, not (just) energy collectors.

It wouldn't be practically applied to fuels for ground transport, but I think it could be applied to air transport fuels. Just the carbon in waste streams in the US would more than suffice for US jet fuel consumption.

All this depends on cost being sufficiently low, of course.

 

[mhalpern]

Yes, it has scaling limits. But the idea has some advantages. It's fairly liberal about the feedstock, unlike enzymatic approaches. It's not just sugar it could process, but really any small organic molecules (furans, fragments of lignin). It potentially uses all the carbon in the biomass, not just part (ethanol production turns a good chunk of the carbon in sugars into CO2). Think of it as exploiting plants as carbon collectors, not (just) energy collectors.

It wouldn't be practically applied to fuels for ground transport, but I think it could be applied to air transport fuels. Just the carbon in waste streams in the US would more than suffice for US jet fuel consumption.

All this depends on cost being sufficiently low, of course.

don't forget bio polymers too, also sewage gas/bio methane as a feedstock. even if we eliminate most single use plastics there's still things like rubber, that will be produced and wear out and need to be processed, even if we go to hydrogen based cement creation and hydrogen process for iron, all these waste products can be broken down into feedstock for various things

 

[John Mahowald]

Sodium-sulfur has been around for a very long time. Back in the '80s people were talking about them for train locomotives, as the high temperature and bulk could easily be handled in a loco, but not in most road vehicles. Also collisions are much rarer on railroads than roads, and molten sulfur, and more particularly molten sodium, are not things you want leaking out after a crash. Part of the loco size advantage was plenty of capacity for both insulating the hot cells, and armoring them against collisions.

Although I understand the cobalt human rights concerns, I am a little skeptical when these are offered as major advantages of different battery chemistries. The future may have a different set of conflict minerals, but the thermodynamics and efficiencies and discharge characteristics of the different battery chemistries are pretty much forever. So if not talking up the good technical points first, I tend to get a little suspicious. Think of the children is not an opening gambit that I expect when discussing energy storage modalities.

And in 2023 Wabtec delivered one battery electric heavy locomotive. Lithium chemistry, apparently from GM. Even when your mass budget is 200 tonnes, a maximum power demand of 3 MW is significant. The whole concept relies on regenerative braking, as 7 MWh storage is not that much range. Probably in a hybrid consist that still has diesel locomotives.

However long distance battery electric rail of any chemistry is pointless. This problem was solved 100 years ago, with overhead wire electrification. Unlimited range. Regenerative braking back to the grid. No time spent recharging. Less mass for storage, leaving more for power or other conveniences or run lighter. Less hazard from energy storage in the event of a collision. Fewer conflict minerals.

Unfortunately American railroads hate spending on infrastructure, even when in the long term it would be much cheaper to operate.

 

[mhalpern]

And in 2023 Wabtec delivered one battery electric heavy locomotive. Lithium chemistry, apparently from GM. Even when your mass budget is 200 tonnes, a maximum power demand of 3 MW is significant. The whole concept relies on regenerative braking, as 7 MWh storage is not that much range. Probably in a hybrid consist that still has diesel locomotives.

However long distance battery electric rail of any chemistry is pointless. This problem was solved 100 years ago, with overhead wire electrification. Unlimited range. Regenerative braking back to the grid. No time spent recharging. Less mass for storage, leaving more for power or other conveniences or run lighter. Less hazard from energy storage in the event of a collision. Fewer conflict minerals.

Unfortunately American railroads hate spending on infrastructure, even when in the long term it would be much cheaper to operate.

there's all sorts of legislative errors with American rail, anyways it probably can make sense to do overhead for the trunk lines and have the battery for where they branch off,

 

[THT]

Increasing global climate temperature averages does not preclude local weather minimums. More global heat drives more variable weather, including disruptions to polar jet streams.
https://theconversation.com/global-...frequency-and-intensity-of-cold-spells-223153

These cold snaps are 1 week events. For the rest of the winter? The hottest ever. The energy needs for heating will decrease.

 

[OrvGull]

And in 2023 Wabtec delivered one battery electric heavy locomotive. Lithium chemistry, apparently from GM. Even when your mass budget is 200 tonnes, a maximum power demand of 3 MW is significant. The whole concept relies on regenerative braking, as 7 MWh storage is not that much range. Probably in a hybrid consist that still has diesel locomotives.

It's fairly common on mountainous western freight routes for the number of distributed locomotives on a long train to be governed by braking capability, not by motive power, so that makes some sense.

However long distance battery electric rail of any chemistry is pointless. This problem was solved 100 years ago, with overhead wire electrification. Unlimited range. Regenerative braking back to the grid. No time spent recharging. Less mass for storage, leaving more for power or other conveniences or run lighter. Less hazard from energy storage in the event of a collision. Fewer conflict minerals.

Unfortunately American railroads hate spending on infrastructure, even when in the long term it would be much cheaper to operate.

CalTrans is electrifying some of its territory with overhead wire, and the remaining portions will still be operated by diesels. There's no plans to use battery-electric locomotives. They're after not just the carbon reduction but also the better acceleration of electric units; their power-to-weight ratio makes them much quicker between stops even for the same top speed, which is important on congested routes.

 

[Walker On Earth]

However long distance battery electric rail of any chemistry is pointless. This problem was solved 100 years ago, with overhead wire electrification. Unlimited range. Regenerative braking back to the grid. No time spent recharging. Less mass for storage, leaving more for power or other conveniences or run lighter. Less hazard from energy storage in the event of a collision. Fewer conflict minerals.

Unfortunately American railroads hate spending on infrastructure, even when in the long term it would be much cheaper to operate.

Probably a very silly question, how vulnerable are overhead wires to illegal tapping? What would motivate such behaviour I wouldn't care to guess, but humans are strange creatures.

 

[wagnerrp]

Probably a very silly question, how vulnerable are overhead wires to illegal tapping? What would motivate such behaviour I wouldn't care to guess, but humans are strange creatures.

About as vulnerable as residential distribution lines, and you don’t hear much about people stealing from those. This is all medium voltage shit. A third rail subway line might only be as low as 1kV, but the overhead stuff can be upwards of 25kV. You need specialized equipment and specialized skill to handle that and not kill yourself.

If the lines aren’t in use, you can power them down and save some energy. If the lines are in use, they’re in use and the next engineer traveling through is liable to see it. In a modern system, you’re going to have monitoring to detect flaws and errors, and an unexpected power loss from someone tapping the system will stand out.

 

[OrvGull]

About as vulnerable as residential distribution lines, and you don’t hear much about people stealing from those. This is all medium voltage shit.

Residential distribution lines are, if anything, easier to tap because they're closer to buildings. And since catenary doesn't normally have side connections any taps would be pretty obvious on inspection.

 

[raxx7]

And in 2023 Wabtec delivered one battery electric heavy locomotive. Lithium chemistry, apparently from GM. Even when your mass budget is 200 tonnes, a maximum power demand of 3 MW is significant. The whole concept relies on regenerative braking, as 7 MWh storage is not that much range. Probably in a hybrid consist that still has diesel locomotives.

However long distance battery electric rail of any chemistry is pointless. This problem was solved 100 years ago, with overhead wire electrification. Unlimited range. Regenerative braking back to the grid. No time spent recharging. Less mass for storage, leaving more for power or other conveniences or run lighter. Less hazard from energy storage in the event of a collision. Fewer conflict minerals.

Copper is a conflict mineral too.
In fact cobalt is usually mined as a secondary product of copper mines.

We really need to fix the "conflict" part here.

 

[Walker On Earth]

Residential distribution lines are, if anything, easier to tap because they're closer to buildings. And since catenary doesn't normally have side connections any taps would be pretty obvious on inspection.

Well, that answers that! Presumably the train makes connection with a bare wire; maybe not? I said it was a very silly question; it's just that I've got a thing for trains is all. Yes, I can make a logical argument for better rails, networks, etc. But I'd be lying if I said I said my underlying fondness had nothing to do with those arguments.

 

[raxx7]

to kill you if you get too close.

So you need proper tools and training to work on a live 25 kV line.

Or you're get
Well, that answers that! Presumably the train makes connection with a bare wire; maybe not?

Yes the train makes connection to a bare wire.

But it's not easy to make a usable tap without getting killed.

You'd want to securely bond your tap wire to the messenger wire and then securely (and discretely) tie it to the bracket and down the mast.
Keep in mind all that stuff moves and shakes with wind and passing trains.

But pretty much everything but the mast is liable to make you crispy in a flash.
So you need proper tools and training to work on a 25 kV line.

 

[OrvGull]

Well, that answers that! Presumably the train makes connection with a bare wire; maybe not?

Yes. Mind you, except in wildfire areas most residential power distribution wires are also bare (other than the drops to individual houses.)

 

[numerobis]

These cold snaps are 1 week events. For the rest of the winter? The hottest ever. The energy needs for heating will decrease.

The fun thing is that you need to build the grid for that cold snap, or else it falls over.

Of course, insulating better reduces the peak demand as well as the average demand -- for both heating and cooling.

 

[wagnerrp]

But it's not easy to make a usable tap without getting killed.

Nah. Wire and hook, insulated and terminated on one end (to a very much not off-the-shelf transformer), and catch the messenger wire.

You'd want to securely bond your tap wire to the messenger wire and then securely (and discretely)

That’s the rub. Doing it in a way that isn’t immediately obvious, and potentially even disruptive to the train.

 

[THT]

The fun thing is that you need to build the grid for that cold snap, or else it falls over.

Of course, insulating better reduces the peak demand as well as the average demand -- for both heating and cooling.

Yes. That’s what energy storage is for, right? Could be grid scale hydrogen, residential thermal, grid scale flow batteries, so on and so forth. Heck, I think at some point in the far future, you could have an electrolyzer at home and generate your own hydrogen, stored in a tank for times you need to use it for heating or electricity if fuel cells get cheap.

I live through winter storm Uri, 4 days without power. Fairly certain we would have been absolutely fine if we had solar, storage and heat pumps at the time. Perhaps this experience really biased me to thinking that residential solar, storage, and heat pump is really the way to go.

 

[DDopson]

Yes, it has scaling limits. But the idea has some advantages. It's fairly liberal about the feedstock, unlike enzymatic approaches. It's not just sugar it could process, but really any small organic molecules (furans, fragments of lignin). It potentially uses all the carbon in the biomass, not just part (ethanol production turns a good chunk of the carbon in sugars into CO2). Think of it as exploiting plants as carbon collectors, not (just) energy collectors.

It wouldn't be practically applied to fuels for ground transport, but I think it could be applied to air transport fuels. Just the carbon in waste streams in the US would more than suffice for US jet fuel consumption.

All this depends on cost being sufficiently low, of course.

You make some interesting arguments. I'd also add that providing energy from Green Hydrogen should be significantly more land efficient than energy provided from bio feedstocks, on account of solar panels collecting a double-digit percentage of insolation while crops return <1%.

I checked the enthalpy of combustion for fructose/glucose versus benzene/hexane, and it's not as different as I'd hoped, roughly +60% gain in enthalpy of combustion for the hydrocarbons over the sugar feedstock.

For example, if this is the chemical transformation:

C₆H₁₂O₆ + 7*H₂ => C₆H₁₄ + 6*H₂0

Then 1 kg of glucose embodies 4.3 kWhr of energy. Add 0.078 kg of Hydrogen (14:180 mass ratio), which embodies 2.6 kWhr of energy produced from ~3.8 kWhr of electricity. This yields 0.6 kg of water and 0.478 kg of hexane, which combusts with 6 kWhr of heat. The 600 grams of water has an enthalpy of formation of -4.4 kWhr, so I suspect this process is exothermic by 5.3 kWhr.

If you did this with actual sugar it would be pretty expensive. Sugar is about $600 / ton, and if green hydrogen is $3 / kg, even if the rest of the process is cost free, that's $130 / MWhr for the resulting hexane. For comparison, at $3/gal, gasoline is $90 / MWhr, so even the most optimistic lower bound on cost for converted sugar puts it above the cost of gasoline. It could easily be several times that.

But with other lower value organic material, there's more potential. Still, my estimates are magically hand-waiving that this process actually works and has no significant costs beyond the hydrogen and organic feedstocks.

 

[DDopson]

Yes. That’s what energy storage is for, right? Could be grid scale hydrogen, residential thermal, grid scale flow batteries, so on and so forth. Heck, I think at some point in the far future, you could have an electrolyzer at home and generate your own hydrogen, stored in a tank for times you need to use it for heating or electricity if fuel cells get cheap.

I live through winter storm Uri, 4 days without power. Fairly certain we would have been absolutely fine if we had solar, storage and heat pumps at the time. Perhaps this experience really biased me to thinking that residential solar, storage, and heat pump is really the way to go.

Hydrogen storage doesn’t scale down very well.

 

[DDopson]

Nah. Wire and hook, insulated and terminated on one end (to a very much not off-the-shelf transformer), and catch the messenger wire.


That’s the rub. Doing it in a way that isn’t immediately obvious, and potentially even disruptive to the train.

The biggest thing that stops people from doing this, aside from the risk of death, is that you need a transformer rated for 25 kV. You can’t just plug these wires into your home’s breaker box. Most people who would be tempted to steal power wouldn’t have a clue where to find such a thing, and they tend to be not portable, so you steal power for some number of months, but then they figure it out and confiscate your transformer which was more expensive than just paying for power.

 

[mhalpern]

Hydrogen storage doesn’t scale down very well.

and hydrogen leaks. almost as badly as helium, but at least helium doesn't react with the pressure vessel walls, making them brittle

 

[mhalpern]

The biggest thing that stops people from doing this, aside from the risk of death, is that you need a transformer rated for 25 kV. You can’t just plug these wires into your home’s breaker box. Most people who would be tempted to steal power wouldn’t have a clue where to find such a thing, and they tend to be not portable, so you steal power for some number of months, but then they figure it out and confiscate your transformer which was more expensive than just paying for power.

and if you ARE going to go through that sort of effort and investment for free power, residential solar and/or wind (starting to be a thing) would be way more practical

 

[wagnerrp]

and if you ARE going to go through that sort of effort and investment for free power, residential solar and/or wind (starting to be a thing) would be way more practical

We're way past practicality. This is about principle!

 

[THT]

and hydrogen leaks. almost as badly as helium, but at least helium doesn't react with the pressure vessel walls, making them brittle

Toyota sells a hydrogen fuel cell car with MSRP starting at about 50k in the USA. They debuted in 2021. There is a 2024 model. (That it is still for sale is curious. Toyota is also really lagging in the BEV vehicle strategy too. Toyota is making a bet here involving the inertia of the fossil fuel industry.)

How long do you think the Toyota Marai's hydrogen tank will last before it needs to be replaced? Same with the fuel cell? At minimum, it will probably be 8 years on the low end due to warranties et al, and 15+ years for 50% of the units? I wonder if Toyota will say what the leakage rate is?

A home backup unit could look something that is in a Toyota Marai, perhaps scaled down by half, and there would need to be a solar powered electrolyzer unit and compressor to fill the tank. With mass production, perhaps a 2x drop in costs?

I'm not wedded to hydrogen. Combine it with DAC make and store whatever CH* du jour fuel that is easy to store. I'd be careful about saying that we can't store hydrogen at small scale though. With the right economic conditions, there could be tanks that can last 20 to 30 year lifetimes. That's long enough for houses, and probably for utilities too.

 

[DDopson]

Just as a hypothetical, I tried to figure out what it would take to purchase a 25 kv transformer, and I got further than I expected...

Your best bet is the probably the market segment of pole-mounted transformers, similar to this $680 model that I found on Alibaba (10 kva is roughly one home worth of electricity):

Now that's intended for stepping down 13.8 kV, so if you plug 25 kV into it, you've got two problems:

First, you are pushing beyond it's rated spec, so it could catch on fire -- and let's be honest; parts from a random Alibaba vendor might catch fire even at their rated voltage -- but it probably won't (the insulation is supposedly certified to 125 kV), and since you're the kind of person willing to steal 25 kV electricity, this risk is a total non-issue.

Second, when you provide it double the spec's input voltage, assuming it doesn't burn, you'll get double the spec's output voltage, which isn't immediately visible on the page, but the IEEE certification sheet says that it's apparently 347V. So that means you'll be getting ~630V from this thing. Since there's three output connectors, you can probably get 315V from either end to the center tap. This isn't the voltage you want.

You could probably fix that problem with 10 x $76 variacs from Amazon.com, and you'd only be running them a few times beyond their rated voltage, so they probably won't burn either:

If one of these does burn, it will arc short, and that will be a lot easier to manage if you also have a HV-rated circuit breaker, but maybe you don't plan ahead like that. Or maybe your illegal tap wire is thin enough to act as a fuse.

Further down the Alibaba seller's page I found this table:

Which lists 25 kV as on option, so while I didn't find a 25 kV sales listing, you can probably order that voltage from the company by emailing them. In fact, that's the biggest challenge I had while researching this stuff; most of the potential vendors aren't set up to do one-off, arms-length web transactions and they clearly expect to receive emails and phone calls from qualified buyers, like an electric utility, which will typically want to order 100's to 1000's of units at once. It's only through the magic of Alibaba that I can get more visibility into what's typically a purely B2B marketplace where the website contains only enough info to generate sales leads.

In that table, I'm unclear whether you can mix and match the input and output voltages. I doubt they stock all 10 x 6 x 5 combinations. What's more likely is that their assembly line has the flexibility to match any of the HV coils with any of the LV coils, but this once again raises the question of whether they'll be willing to do that for for someone buying only a single unit.

When you contact this company asking to purchase only one unit, that could raise suspicions, so I suggest the following ruse: tell them you are the purchasing manager for your rural town's electrical coop, and that you wish to purchase a demo unit that your organization can field test before committing to a larger purchase order. If you want to really sell the illusion, clone an existing coop's website and change the "contact us" page to endpoints that you control. That will add a few counts of wire-fraud to your indictment and makes it easier for the feds to take over your case if they feel like it.

It seems like you might actually be able to purchase a 25 kV transformer for under $1000, although you may have to lie a bit, and shipping a few hundred pounds of metal from China probably isn't cheap, and you'll need several friends (accomplices!) or some heavy equipment to be able to lift and maneuver this thing into position, and then at your trial, the delivery guy is going to testify that he thought it was super sketchy he was dropping off a gigantic transformer at someone's residential address. So it's possible; it's just technically intimidating to most people, and the people who aren't technically intimidated by specc'ing out a custom-assembled transformer from China are usually able to make enough money that they aren't motivated to steal electricity from 25 kV distribution lines. Stealing is usually a crime of opportunity, and this is something that requires extensive planning. I'm pretty sure I could pull off the installation, 50/50 on being allowed to buy the parts, even less sure about how long I could avoid detection, and completely confident that this is a terrible idea with nowhere near enough upside to compensate for the jail time.

 

[DDopson]

and if you ARE going to go through that sort of effort and investment for free power, residential solar and/or wind (starting to be a thing) would be way more practical

More practical, yes. A better idea, double yes. Cheaper? no. The transformer provides all of your power for 10% of the cost of solar panels that only offset some of your power. You can bank the 90% savings for use in your prison commissary account.

 

[mhalpern]

More practical, yes. A better idea, double yes. Cheaper? no. The transformer provides all of your power for 10% of the cost of solar panels that only offset some of your power. You can bank the 90% savings for use in your prison commissary account.

long term costs. and i did mention residential wind for a reason, depending on location those can work better, alternatively both, plus battery or net metering big initial investment sure, but over time...

 

[DDopson]

and hydrogen leaks. almost as badly as helium, but at least helium doesn't react with the pressure vessel walls, making them brittle

Those are engineering considerations, but solvable ones.

In NASA's Hydrogen Embrittlement report, there's a long table spanning pages 20, 21, and 22, rating the embrittlement sensitivity of various materials. They also have specialized sections for dealing with hot hydrogen (eg 700K) and aqueous hydrogen environments, but for vanilla high pressure hydrogen gas, stainless steel does very well.

Here's the section for Austenitic stainless steels, which is what's generally used for cost-optimized hydrogen storage tanks:

In particular, stainless 316 has an enbrittlement rating of "negligible". That's a rather vanilla alloy that I can buy online here, in any of a dozen thicknesses, cut to size.

Leakage rates through the bulk of the material are negligible, low enough that a similar Sandia report says, "For some materials, such as austenitic stainless steels, testing in external hydrogen may not produce relevant data because of the slow rate of hydrogen transport in these materials" (page. 8), meaning that hydrogen moves through them so slowly that a meaningful internal concentration can't be established during the testing interval. So Sandia uses various other methods to accelerate that process and get more hydrogen inside the metal lattice.

There's some concerns that machining and working can create local Martensite transformations that are more vulnerable, so it's wise to consult a materials expert when designing a hydrogen tank production process, but this is generally a solved problem and there's a number of suppliers selling stainless tanks rated for hydrogen storage. The main purpose of these embrittlement reports is to serve the needs of specialized spaceflight applications where there might be a dozen other intersecting requirements that force a much wider range of materials to be considered.

Even if the facility has a higher leakage rate from various valves and fittings, this is primarily a concern indoors where hydrogen can accumulate near ceilings. For any outdoors or well-ventilated facilities, a slow loss of hydrogen through valves and fittings is non-problematic. The losses from hydrogen leakage are going to be orders-of-magnitude less significant than the losses from producing hydrogen via electrolysis with ~68% efficiency.