3 MWh is a trivial amount of storage. That's less than 10 seconds of this plant's output. To put this in perspective, the USA uses 11.5 TWh of electricity each day. That's just under 500 GWh per hour. You'd need a lot of megapacks to provision 8 hours of storage. The Eland project you mention has 4 hours of storage, it's not a 24 hour production system.
The reality is that renewables are currently only viable to supplement a grid primary backed by a dispatchable source of energy. If you have loads of hydroelectricity, that's fine, but the regions that don't have hydroelectric potential are going to be stuck burning fossil fuels until a massive storage breakthrough is found.
The paper also assumes we'll make have feasible CO2 energy capture and hydrogen electrolysis and storage. It required time, effort, capital, and and multiple engineering breakthroughs. If your plan is contingent on technologies that aren't available... it's just a long winded way of saying you don't have a plan.
Actually, we just need improvements in fusion power and then we don't need solar, wind, or battery storage!
It also assumes a vast hydrogen electric grid storage network - this is only theoretical, nobody has actually deployed a facility that converts electricity to hydrogen, and back to electricity. At best this is, "scale up heretofore unproven technologies", not "existing technologies".
In the same sense that commercial breeder reactors are theoretical (which is conservative, as you can't actually buy a breeder reactor). But nuclear advocates don't talk about those much, even though they'd be needed for a nuclear powered world.
But we don't need commerical breeder reactors. The USA just needs to build 4 PWRs for each reactor it presently has to generate electricity entirely from hydro and nuclear. This is vastly more feasible than provisioning terawatt hours of energy storage.
"Just scale up" is a good summary of how to decarbonize through nuclear power. We have decades of experience building nuclear plants. Not so with hydrogen based electricity storage. Plans for renewable grids call for the use of novel electricity storage systems because none of the existing storage mechanisms are feasible. Until we've built the storage mechanisms proposed, any plan involving it's use is effectively hand-waving a big part of its implementation.
Powering the world (all energy, not just the grid, and not just the grid in the US) with PWRs won't work, because we run out of cheap uranium too quickly. Breeding is needed for sustainable use of nuclear.
Sure seawater extraction is more expensive. But procuring raw uranium is a tiny fraction of nuclear's cost. You'll see statistics saying nuclear fuel is a significant cost, but most of that expense is from enrichment not extracting raw uranium.
Seawater extraction is even less plausible than breeders. The polyamidoxime fibers that article discusses do not have sufficiently long service lives. Also, if the uranium were to be burned in PWRs, the effective power per ocean area of uranium collectors would be much less than the effective power/area from photovoltaics.
Uranium is a small fraction of nuclear's cost at current uranium prices. But eventually that runs out, and the price of uranium would increase dramatically. This has always been the motivation for breeders.
> The cost of raw uranium contributes about $0.0015/kWh
Even if this increases by an order of magnitude, this is not significantly impacting the cost of nuclear power. Heck, even two orders of magnitude still amounts to ~1% increase in net cost per KWh.
RE your edit after I commented:
> Uranium is a small fraction of nuclear's cost at current uranium prices. But eventually that runs out, and the price of uranium would increase dramatically. This has always been the motivation for breeders.
Again, the cost of raw uranium extraction amounts to $0.0015/kWh in nuclear generation. A 100x cost increase will not amount to even a quarter of a cent per KWh. This is the power of fissile energy density: it's so energy dense that the cost of extraction is largely decoupled from the net cost of nuclear power.
By comparison, how would the price of lithium ion batteries be affected if the price of lithium carbonate increases by 100x? Half of a battery's cost comes from the cost of cathode material: https://www.visualcapitalist.com/breaking-down-the-cost-of-a...
If $0.0015/kWh is the current fuel cost, a 100x increase would bring it up to $0.15/kWh. That's 15 cents per kilowatt hour, not a fraction of a cent. It would make nuclear power among the most expensive of electricity sources from fuel cost alone.
If lithium increased in price by 100x, we'd switch over to one of the many other options for energy storage. If uranium increases in price by 100x, burner reactors are screwed (well, even more screwed than they already are.)
"many other options" like what? You can't just say we'd use alternatives and then neglect to specify what those alternatives are. All storage options available to us fall short. Hydropower is geographically limited. Batteries are in too short supply, and are mostly being directed to other applications. Plans for a mostly intermittent grid invariably call for hydrogen, compressed air, giant flywheels, or something else to solve the storage problem. We have no practical experience building electric storage with these systems, so it's effectively a giant hand-wave.
A plan that's dependent on something like hydrogen electric storage is like a plan calling for widespread deep-drilled geothermal power: We have plenty of experience with drilling, and steam turbines. Iceland has plenty of geothermal power - but it sits right on a fault line. That's no guarantee we'll actually be able to build geographically-independent geothermal power. Would you view a plan that involves widespread installation of geothermal power as feasible?
There are many chemistries for batteries. We're even seeing some of them pushed to commercialization. Chemistries based on common elements like sodium or iron would evade concerns about material availability.
There are thermal storage technologies. An example is pumped thermal storage. This involves (1) adiabatically compressing argon, (2) transferring heat from the compressed argon to a hot store (say, molten "solar salt", a potassium/sodium nitrate salt mix) by a countercurrent heat exchanger, (3) expanding the cooled argon back to the initial pressure, (4) using that now cold argon to extract heat from a "cold store", say liquid hexane, cooling it to -100 C. To discharge, reverse this process. Round trip efficiencies similar to pumped hydro could be achieved. The high temperature side of this process is within the creep range of ordinary steel, so no exotic materials are required.
Resistively heated thermal stores would not be quite as efficient (maybe in the low 50s%) and involve higher temperature (~1200 C), but could work with existing gas turbines. Babcock and Wilcox are commercializing this now, using their very nifty direct contact sand/gas fluidized bed heat exchanger. The storage medium here would be ordinary sand, of which there is an unlimited supply.
This last approach also allows an external heat source, such as hydrogen combustion, to act as a backup heat source. So if your thermal stores run out, you can keep running them by burning hydrogen (or some other e-fuel). The marginal capital cost of this capability would be very low, just that of adding a fluidized bed hydrogen combustor to heat the sand.
Thermal storage has only been used for district heating. There is no commercial electric thermal storage project in existence. Babcock and Wilcox have not broken ground on a prototype thermal electric storage plant, let alone a commercial one. They signed an intellectual property agreement [1], this is not even remotely the same thing as commercialization.
Hydrogen electric storage has issues producing hydrogen without emitting fossil fuels: almost all hydrogen produced today is through steam reformation which emits carbon dioxide. Electrolysis has issues with corroding electrodes, in particular. We've known about electrolysis for decades (centuries?) but its disadvantages have not been solved. Likewise, how long have sodium and iron batteries been on the verge of commercialization? How long did lithium ion batteries take to reach the scale sufficient for EVs? Sources say that they're projection sodium ion batteries to be produced at 20 GWh per year by 2030 [2]. Even if that level of optimism pans out, this is nowhere near a scale sufficient for grid storage.
People still hope for lithium ion batteries to deliver, because it's the best (or least-bad) option and none of the competitors are set to unseat it. And remember, almost all of this battery production is going to EVs and electronics, only a fraction of it is going to grid storage.
> It's a trivial amount of storage for a trivial amount of money. Do the math, don't hand wave.
Sure thing! Right now we have an annual battery production rate of 500 GWh globally [1]. If we're going to use global battery production figures, we need to use global electricity consumption, which is about 70 TWh per day [2]. How much storage we'll need varies, depending on the mix of solar and wind. Estimates I can find say 12 hours on the low end, 3 weeks on the high end [3].
So even with the optimistic estimates of 12 hours, that means we'd need 35,000 GWh of storage. This is 70 years of global production at our current rate, for the optimistic storage estimates. And of course we can't dedicate all battery production to grid storage - we need them for electric vehicles, and electrical devices
Production of batteries may grow in the future, but then again so will electricity demand as countries develop and transportation becomes more electrified. Furthermore, we're not counting the fact that batteries have limited lifetimes. It depends on depth of discharge, but we're usually looking at 1,500 to 3,000 cycles before they're substantially degraded.
As your can see, the scale of battery production and the scale of energy storage required to make intermittent sources variable are totally mismatched. The reality is there is no amount of money that will provision the battery storage required, because if countries across the world start trying to buy terawatt hours of batteries when only 500GWh of batteries are produced then the cost of batteries will skyrocket. Cathode material already
> The Eland project provides 24 hour power with only 4hr of storage. That's the demand curve in action.
The "demand curve" means Eland doesn't provide 24 hours of power at its rated output. It provides a fraction of its rated power at night and tells customers not to use as much electricity. This may work for some consumers, but not others. The pumps powering your sewage system can't demand shift if you want to flush your toilet at night. The reality is that peak energy demand happens at night [4], when storage isn't producing electricity. Eland can do this demand shift because other producers are picking up the slack.
When you read about storage projects you need to be on the lookout for weasel-words like this. Demand curve means they produce a fraction of the rated power output during periods of non-production. If I have a plant that produces 1,000 MW during the date and 100=MW at night, that's technically 24 hours of production. But clearly this is not the same thing as a nuclear plant that produces 1n000 MW at all hours.
The US alone has 800GWh of battery plants in the pipeline, to come online before 2026.[1] China has multiple TWh's worth. We can build 35TWh or even 350TWh of batteries a lot faster and than we can build the multiple TW of nuclear plants that would be necessary to decarbonize electricity without storage.
> The reality is that peak energy demand happens at night
Peak net energy demand happens at night. Peak gross demand is during the day.
> Eland can do this demand shift because other producers are picking up the slack.
Eland is producing at a rate identical to the California demand curve, it's in their contract. It's the solar producers who don't have solar along with consumer rooftop solar that's causing the duck curve daytime demand drop.
> If I have a plant that produces 1,000 MW during the date and 100=MW at night, that's technically 24 hours of production. But clearly this is not the same thing as a nuclear plant that produces 1000 MW at all hours.
But the former costs 1/10th of the latter, so you build 10 of them to get 1000MW at night and 10000MW during the day.
The "pipeline" you're referring to is a measure of battery manufacturing capacity. This is not nearly the same thing as actual production figures. Capacity utilization in 2022 was under 35%. In other words, 100 GWh of capacity only translated into 35 GWh of battery production. This is because the majority of cost of lithium ion batteries is in raw materials, namely cathode material [1]. A huge amount of capacity is useless if you don't have the input materials to feed your factories.
You can't store energy in a battery factory, you store energy in batteries. Cite the actual production figures, not the stated capacity figures (spoiler alert: it was just under 500 GWh last year.).
And to reiterate, the vast majority of this production is not going to grid storage, it's going to EVs and electronics. Even if battery production matches the predicted growth, it's still vastly insufficient to provision grid storage without heavily crippling EV rollout.
> Eland is producing at a rate identical to the California demand curve, it's in their contract. It's the solar producers who don't have solar along with consumer rooftop solar that's causing the duck curve daytime demand drop
Demand remains high well into midnight. I'm not sure why you think matching the demand curve is somehow going to mean you're going to get away with less storage. Unless Eland is going to be producing much less than its nameplate capacity at all times of day, 4 hours of storage is nowhere near enough for it to match the demand curve. And remember, solar is also subject to cloud cover. I'm sure Eland has clauses exempting it during periods of cloud coverage otherwise they'd need weeks of storage not hours.
> If I have a plant that produces 1,000 MW during the date and 100=MW at night, that's technically 24 hours of production. But clearly this is not the same thing as a nuclear plant that produces 1000 MW at all hours. But the former costs 1/10th of the latter, so you build 10 of them to get 1000MW at night and 10000MW during the day.
The former doesn't have a price tag, because no amount of money in the world will buy you that much lithium ion batteries. Again, the world uses 70,000 GWh of electricty per day, most of that being consumed when solar is not producing electricity. No amount of money can fulfill that amount of storage.
To me it seems reasonable to assume that not only will battery consumption grow, it will grow exponentially (over the medium term - say the next 10 - 50 years). Rationale:
- There is high demand
- The production process is well established technology that can be easily replicated
- There are no obvious limits to growth in the medium term (In the short-term there are resource constraints as mines are opened).
Your link 3 also contains this line: "The solar heavy network wouldn’t need energy storage with an HVDC network."
IOW, the US could build a 100% solar+wind+hydro grid WITHOUT ANY STORAGE. The wind is always blowing somewhere in the US.
Of course that much HVDC and overbuild would be ridiculously expensive, but some HVDC and some batteries are a lot cheaper than only HVDC or only batteries.
The reality is that renewables are currently only viable to supplement a grid primary backed by a dispatchable source of energy. If you have loads of hydroelectricity, that's fine, but the regions that don't have hydroelectric potential are going to be stuck burning fossil fuels until a massive storage breakthrough is found.