I've seen this criticism that it's "difficult to reason about which method will actually be called because of the type system" once before, but it absolutely flummoxes me... I have literally never been confused about which method is going to be called by my code, and I'm not even a proper computer scientist (just a regular scientist scientist).
Maybe this is just an issue of not having years of OO habits influencing the way I reason about dispatch in Julia?? Honestly not sure.
I'll go one further: Hydrogen does nothing. It's a bad battery.
After following this for more than a decade (starting with a bit of undergrad research on possible alternative fuel cell electrode materials -- albeit not a field that I'm in any way involved with any more), it just feels like there's been very little progress on fuel cells, or on storage and transport. Meanwhile, progress on Li-based batteries has been slow but steady. It's not really clear to me what advantages H has over Li as an electron donor, at this point.
Hydrogen is a battery with very particular uses cases.
In particular: hydrogen is bad for use cases with large numbers of charge/discharge cycles, because the "cost of inefficiency" is proportional to the number of such cycles.
However, for use cases with small numbers of charge cycles, like seasonal storage or backup against rare grid outages, hydrogen's big advantage -- the low cost of storing it, vs. typical short term storage technologies like batteries -- will dominate. Storing hydrogen underground in caverns has a per energy capacity capital cost of just $1/kWh, two orders of magnitude cheaper than Li-ion batteries.
Let’s assume at scale you’re buying seasonal power for 0$ so efficiency doesn’t matter and selling it at 10c/kWh given 1$/kWh and a once a year discharge you might break even in 10 years which looks fine except...
1$/kWh is only storage for already existing hydrogen. For this application you also need equipment to both produce and burn it which adds to these costs. Hydrogen generation can’t depend on 0$ prices for very long each week in the off season so you either need a lot of excess equipment that’s rarely used or be willing to pay more for electricity. Further, nobody building a grid would be willing to depend on seasonal storage running out on the last day it’s needed. So you need a large guaranteed storage surplus alongside redundancy in your generating capacity.
Start running the numbers and the annual ROI doesn’t look to be even enough to pay for the interest on your setup costs let alone profit. It might have some ultra niche applications but the economics don’t seem to work out for large scale deployment.
Yes, but the producing and burning is not proportional to the amount of energy stored, but to the rate at which the hydrogen is produced or consumed.
In the 100% renewable grid, electricity actually will be in surplus a good part of the time, because so much excess capacity would be installed. This is not the case now, so you can't use the current frequency at which curtailment occurs as some sort of baseline.
Yes, you'd need excess storage so it doesn't run out. Fortunately hydrogen storage is cheap. This is another argument for hydrogen over batteries.
You can run the numbers and see that in a hypothetical system for providing steady power in Germany, including hydrogen storage can cut the total cost nearly in half (subject to assumptions, of course.) Doing it with just wind, solar, and batteries ends up being far more expensive.
The amount of energy stored or is still limited by the rate it can be generated.
The absolute best case for seasonal storage is 1kW * 9 months = 6,480 kWh per 1kW of equipment if you are willing to pay unlimited prices per kWh.
However if you are depending on 0$/kWh which hypothetically occurs 1% of the time you are down to 55kWh per 1kW of equipment. In a world with mass storage wholesale prices will spend less time at 0$ so what matters is the prices when you’re operating not historic prices before you build these facilities.
PS: Conversely, if you’re using that stored energy the grid isn’t going to have a deficit 24/7 the entire winter at your maximum production rate. If you average 8 hours a day for 2 months that’s 480 hours of operation per year. Gas turbines are cheap but not that cheap.
Here in Europe peak electric prices have been far above $1/kWh, rising to around $7/kWh in the worst-hit regions.
Due to the build-out of wind power we have also had a few nights of negative electricity prices in recent months.
If we had a hydrogen energy storage facility, it could probably have recouped quite a portion of its capital costs this year, depending on its scale. Europe will not be building much base load power in the coming years, so the imbalance of the grid will only continue to rise, allowing for more business opportunities in the energy storage sector.
Europe is experiencing those prices due to a dependence on fuels it doesn’t produce and a lack of daily energy storage.
Extrapoatgng prices to stay the same when you swap energy sources and introduce two different kinds of large scale energy sources is clearly wrong.
Ultra low or ultra high prices will represent a small chunk wholesale prices after you construct long term storage. You can’t build equipment that’s utilized 0.01% of the time and expect significant profit.
>hydrogen's big advantage -- the low cost of storing it
Hydrogen by its very nature, due to it being the smallest atom, embeds itself into the walls of its container. It will rot the metal walls you use to hold it long term.
It's stored underground in caverns, not in metal pressure vessels. This is a demonstrated technology. It's also the same way natural gas is stored. The cheapest option is solution mined cavities in salt formations. Europe (for example) has enough salt formations to store many petawatt hours of hydrogen.
What’s the pricing compared to stored energy like pumping water up a hill? I get that it’s not exactly a universal strategy but not like underground caverns don’t have the same issue
The main issue with pumped storage is you need a lot of water. Imagine a elevated water tank like that used on farms. 20,000 gallons (75,000 litres) of water elevated at 18 feet (5.4m) has 1.1kWh of potential energy.
900m is a huge elevation difference. The highest pumped power dam currently in Japan (by hydraulic height, after looking at almost all the Japanese hydro pages on English Wikipedia) is about 780 m; the median is just under 400 m. Presumably most of the other hydroelectric dams have already been investigated for pumped power, but lack a sufficiently large lower reservoir.
Seasonal storage is an interesting idea. Rare grid outages seems pretty easy with batteries if the South Australia example is anything to go by though, and for medium-term storage there's also pumped hydro -- not sure where that compares in cost?
Rare prolonged outages are bad for batteries, since the capital cost is too high. You want something that has very low capital cost, even if it burns a fuel. Simple cycle gas turbines power plants might cost $0.50/W.
Existing battery technology works best when you don’t charge to 100% or discharge to 0%. On top of this you want oversized batteries to deal with battery degradation over time. This means any large scale battery system includes a buffer beyond normal use which you would only use if wholesale prices spiked.
On top of this grid operators want generation redundancy in case an individual power plant goes offline for whatever reason. Combining both you get quite a lot of excess capacity compared to the current grid.
Batteries sufficient for short term leveling would run out too quickly. If you build enough batteries for prolonged outages most of them would be unused during the leveling of short term fluctuations.
How long can south Australia power their load from batteries? I thought they had the one 100MWH battery so basically could power 100k house for an hour? And that battery was over 100 million dollars.
South Australia aims to reach 100 per cent “net renewables” within a few years – over a full year – but in the past week it has already done better than that.
It would appear they are aiming to export excess renewable power to Victoria (neighbouring state).
I thought we were taking about battery capacity preventing a blackout during a major grid outage and not installed renewable capacity meeting the demand.
.South Australia had (maybe still has) the "world's largest battery" (installed by Tesla | Musk) which is an integral part of the SA state power grid that carries it through night times with no wind . . .
If there's "a major grid outage" no large scale battery (or gas fired plant or coal fired plant, etc) will prevent blackout .. as there is "a major grid outage" preventing power from being delivered.
Individual homes would be left to do what individual Australian homes do during bush fires, floods, tree falls, etc and turn to gas lanterns, home generators, and any community hubs that feed local rooftop solar through a local small scale battery (not common as yet, but they're about and increasingly so).
Fuel cells might end up better than batteries if you consider the cost/lifetime of batteries. Energy density and safety are also valid considerations, the batteries are already at the limit of what you'd want to sit on top.
Hydrogen by itself has the energy density of zero. Batteries are nearing the energy density of high explosives (and for some types, such as Li-S, exceed it), and, unlike hydrogen, have all the components required for energy yield within micrometers of each other.
Energy density. I'm not sure exactly what it is for lifepo4 but it's lower than 1,406.6 kWh/m^3 for hydrogen at 700 bar, i think roughly half.
Both compare poorly against diesel though so I'm left wondering if synthetic fossil fuels produced from renewable inputs might not actually be the way to go. In the beginning it seemed like efficiency was going to be important and a limiting factor to all this, and batteries definitely have an edge on fuels produced from renewable sources. But now it's seeming like actually producing large amounts of energy isn't as much of a problem as ensuring that it is available at the point of consumption economically and logistically. Synthetic fossil fuels that pull carbon from the atmosphere would be carbon neutral and fit neatly into the existing system with no other modifications.
It stands to reason there's a threshold at which the cost of production is so much lower than the cost of transmission and storage that it makes sense to take efficiency losses for storage and transmission gains.
Hydrogen is the way to send energy from sunny places, like Australia to not-so-sunny places, like Japan. You can't send batteries, and you can't lay a cable that long. You can try to pack that energy in a different form of chemical energy like ammonia, or methylcyclohexane, or methanol, or synthetic methane or gasoline. The jury is still out. Europe is investing big time in hydrogen too, so chances are that hydrogen makes sense.
You absolutely could lay a cable that long, and IMO we should. There is no reason not to export abundant renewable energy today while we can, and figure out the long term storage issues as we go.
Hydrogen can be manufactured anywhere you have seawater and electricity, so it would be a much better use of resources to lay a subsea superconducting cable once and let Japan store power by generating hydrogen locally.
One large LNG carrier of class Q-Max carries 260000 m3 of liquefied gas. If we stitch to hydrogen, that contains 2.2 million gigajoules of energy, which is 614 GWh, or a bit more than 25 GWd. If we assume a conversion efficiency of 60%, then that's about 15 GWd of electricity after taking into account all the losses. If one carrier arrives every 15 days, then this can produce a sustained 1 GW of electricity, which is about the same as a full size nuclear reactor. The transit from Australia to Japan takes about 30 days, so it would take 4 carriers to arrange for 1 to reach Japan once every 15 days. Such a carrier costs about $200 MM, so you get to invest about $1 BN to get a sustained 1GW of electricity in Japan.
How does this compare to submarine power cables? [1] is an example of a 1200 km power cable that will cost about $1 BN for a capacity of 2 GW. This power cable will be across the Mediterranean Sea, much shallower than the Pacific, but let's ignore that. The distance between Australia and Japan is about 6800 km, so you'd need a cable 5 times longer than the one above. This would translate in about $2.5 BN of capital investment per 1 GW of electricity.
Except H2 carrier won't carry 1/2 LH2 as LNG but 1/4, liquefaction will consume 35% to 45% of the LHV energy, 9 times more leaks than LNG, completely new infra, and all existing H2 carrier have issues we are nowhere near building them as the same size of LNG and it will cost way more :
- I never mentioned H2 carriers carry 1/2 the energy of LNG. I used the 8.5 MJ/m3 LHV density of H2, which is 38% of the one for LNG, of 22.2 MJ/m3 [1].
- the 35% to 45% liquefaction energy cost. [2] is a paper written by the Department of Energy stating that the range in the industry (as of now) is 10-20 kWh/kg, which is 30% to 60%. Which means 30% is possible. If we massively scale up this industry, lower values are conceivable
- 1% losses to leaks per day. This number is pulled out of a hat (you didn't mention it, but the tweet you linked to did). The leaks of H2 are not very well studied, so 1% is just a conjecture, and probably a very pessimistic one. [2] is a review of the literature done in July 2022. It finds estimates for lifetime leaks of between 0.2% and 3%. Not daily leaks.
- existing H2 carriers have issues. Of course. The economy is geared towards LNG carriers at this point. 20 years ago LNG carriers were a curiosity, and now they are an essential part of the world's energy infrastructure. LH2 carriers are not needed at this point, since the H2 production is just a drop in the bucket compared to natural gas.
- the H2 infrastructure. We don't need to replace all the natural gas infrastructure with H2 infrastructure. As you may have noticed, there's been some noise recently about retiring natural gas stoves for homes. The move is towards replacing a lot of natural gas infrastructure with power cables. H2 will just be needed at the receiving terminals, where it's going to be stored locally, and converted to electricity based on demand.
What about the cost of the supporting infrastructure for cramming that 1GW into hydrogen and back to electricity? Well, with fuel-cell cars you don't need centralized infrastructure for converting back, but then you need infrastructure to distribute it inland. You still need the supporting infrastructure on Australia's side for the electrolysis.
Of course the power cable would also need supporting infra, other than the length of the cable, but I have a hunch that it would cost way less. I have no numbers though.
From the article "Crucially, he argued the subsea cable was likely to be its steepest hurdle, pointing out that it was more than five times longer than the world's biggest, the 767-kilometre Viking link between the UK and Denmark currently under construction"
The length was fine .. the single breakable deeply submersed part where it crosses multiple faultlines in an earthquake rich volcanic region was bonkers.
See:
Atlassian CEO's bonkers scheme to pipe electricity from Australia to Singapore collapses
It also makes a lot more sense to scale up the grid and battery manufacturing than to try and invent entirely new infrastructure for hydrogen production, storage, and transport. I had an open mind about hydrogen in decades past, but it increasingly just seems like a scam to get money to develop something that doesn't work and isn't economically viable in most cases.
I think it's actually significantly worse than just a scam. It's a way for oil companies to create a value added product that can be sold by moving the carbon emissions out of one country and into another. They can then sell the hydrogen as "green" by washing the hydrogen with other sources even though it came from oil.
I think most of the enthusiasm lies in the toxicity or safety of the energy store. Lithium batteries are toxic waste that doesn't get recycled well yet and requires minerals currently produced by child laborers in appalling conditions. Hydrogen fuel cells produce pure water as their byproduct and could theoretically be loaded with hydrogen fuel produced through green-powered electrolysis. They both explode on a bad day, but one rapidly oxidizes in a more environmentally friendly way.
> Lithium batteries are toxic waste that doesn't get recycled well yet
Actually it does get recycled well, especially with larger batteries. There's just been very little that actually needed recycling that was sufficient to run a business. There's many smaller size businesses making healthy profit off lithium battery recycling already.
Disagree - the biggest nominal advantage of hydrogen is mass storage. In theory, tanks scale up in capacity more easily than battery cells (perhaps to the point of seasonal storage). In almost every other respect hydrogen would be worse than lithium batteries (requires complex infrastructure for power conversion, terrible roundtrip efficiency, etc)
In the end, the shortfalls of hydrogen are turning out to be simply too insurmountable.
I think there are use cases where it's a very good battery if small enough devices are created. Specifically, an empty cell on its own is going to be much cheaper than a lithium battery. I could swap and store many cells in my garage, but I can't do that with a typical mounted battery. This means the capacity of cells would be limited by physical storage space. And if my solar system produces a lot more electricity that I could use on a normal day, it could make sense for a rainy day.
Hydrogen automotive technologies are a research scientist’s dream. Basically, it represents life long employment with no need to produce useful results.
Management at many automotive companies likely love it for that reason too, since putting money into it makes it look like they are doing something to change when in reality they are not doing anything at all.
Here is a neat fact about hydrogen vehicles. Fueling them causes the nozzles to cool to below freezing temperatures. Try fueling vehicle after vehicle and the nozzle will freeze to each one. Coincidentally, hydrogen vehicle refueling is a sadist’s dream.
It is an observation and it fits the data very well. Automotive use of hydrogen has severe feasibility problems and no amount of research is likely to fix them. Not only does it require conversion of useful energy into it at a loss, but it’s transport, storage and use is extremely expensive. You are basically fighting physics to try to get a sane result. Meanwhile, we have a very promising results in battery electrics that far exceed the best case results from hydrogen, yet people want to continue pouring money into the money hole that is a hydrogen economy. Hydrogen’s best attribute in automotive applications is that it will go nowhere.
As for accomplishing nothing, if it put food on the table, it certainly did accomplish something, just not what was being promised to the people who funded it.
It has good power/weight ratio in theory, esp. if you're burning it (c.f. space shuttle), but hard to store or transport it both densely and safely in a practical way -- i.e., unless you're comfortable dragging around cryogenic lH2 in your sports car
The more you need to care about the weight of energy storage the more hydrogen is useful. For land vehicles hydrogen is basically completely pointless and for stationary storage it's truly pointless. Hydrogen makes some sense for aircraft but not for anything on land.
It is a bad battery (along certain dimensions). But there is serious doubt as to whether the world actually has enough Lithium and other rare earths to actually meet battery demand indefinitely, even assuming we get the supply chains and infrastructure to where the materials are infinitely recyclable.
Lithium is not a rare earth metal (neither is cobalt). There is actually quite a lot of it, but it's evenly distributed so needs a lot of demand to be worth extracting from seawater. On the other hand, if we got a lot of cheap lithium we could use it to improve everyone's mental health like those fluoride conspiracy theories.
Notably people think Tesla gets lithium from Bolivia because Elon made a joke about it once, but I think it actually comes from Australia.
Dr. Goodenough’s new battery design allows people to use either sodium or lithium. Given that the entire world has adopted his previous battery designs, I would not be surprised if sodium based batteries are next. Sodium is so incredibly prevalent in the earth’s crust that scarcity should not be a problem.
It seems like you have some emotional baggage involved here.
I use Julia every day (for scientific computing). I have never worked with or for the Julia Computing folks, but don't agree with your characterization of them. I like Fortran too, but personally I would rather use Julia if I have the choice.
I'm teaching an intro programming course (discipline-specific, for Earth sciences) in Julia at Dartmouth. So far so good I think -- but definitely on the sciences side of things.
Latency / "ttfx" for all sorts of things has also dropped dramatically over the past ~year, and will get another big boost with the native code caching PR
A correlation between mass extinctions and certain volcanic episodes known as "large igneous provinces" has been emerging over the last decade or two; this paper quantifies that correlation and suggests that there may have been an extinction at the end of the Cretaceous even without the asteroid impact.
All the computational work (and plotting) in here was done with Julia, including the parallel calculations with MPI.jl and VectorizedRNG.jl
