As has been pointed out to you many times before, there is no need to use batteries to store utility-scale energy, so battery production capacity is immaterial. Mentioning battery production of the moment again is disingenuous, not to say dishonest. Production capacity, anyway, increases with demand.

The key principle of bulk energy storage is E = Fx, applied liberally worldwide for centuries. It is taught to every freshman engineering student. Nothing blocks further application of the principle, at any scale.

And as has been pointed out numerous times, no existing alpine lake is needed for hydro storage. And, the site does not need substantial "transportation infrastructure". Dozens of hydro dams, still in use, were built in California's Sierra Nevada mountains in the 1920s via roads a car cannot use.

> The key principle of bulk energy storage is E = Fx, applied liberally worldwide for centuries. It is taught to every freshman engineering student

Hi there, I graduated engineering and am currently applying for professional licensure. I took only one course focused on energy, but I've never heard of E=Fx. Googling it brought up no relevant results. Could you expand on what it is?

They are likely referring to force * distance = energy. Which in context is a pitch for pumped hydro storage.

This all sounds well and good, however it’s highly unclear that utility scale pumped hydro is viable. To make it work you need to have plentiful water, limited evaporative loss/other losses, and two large basins to store both the charge, and discharge of water.

In the event of drought, these facilities could become impractical. Hydro facilities have their own environmental concerns. Combined with shifting climates and rainfall patterns there are many challenges to be solved. (some of which go away if the hydro storage is in underground ceiled chambers… which also has a cost associated)

Pumped hydro is not the only storage; otherwise I would have said E = mgh.

Pumped hydro is practical in many, many more places than have hydro generation today, because unlike those, it does not need a watershed. It can use a deep underground cavity where a hill is not forthcoming. Where water is scarce, other methods will be used.

Other applications of Fx include (but are not limited to) compressed air, and buoyancy.

Places that run low on storage resource can import and burn fuel, as they do now, or schedule power from a transmission line, where they have one. Soon, liquified anhydrous ammonia will be cheapest and most practical, but liquified hydrogen may be cheaper and sufficiently practical for bigger utilities. Ammonia has the advantage that it does not need cryogenic treatment. These will be available from numerous tropical sources.

You may go back to your freshman physics textbook.

If you get a professional engineering license without recalling basic Newtonian physics, that just tells us the licensing process has utterly failed us.

> You may go back to your freshman physics textbook.

I may, but I live in a country that doesn't use the word freshman, so I don't know which year physics text that would be.

I assume from context you were meaning to refer to gravitational potential energy, which is generally represented as ∆U=mg∆h (change in gravitational potential energy equals mass times gravity times change in height). The variables you used (E=Fx) would mean energy equals force times (variable). From dimensional analysis the variable would have to be units of length (m), however it clearly only applies in the vertical dimension so it's better to use a specific variable like ∆h

Regardless, energy storage via gravitational potential energy (i.e. pumped storage) has been in use for about a century, and still makes up a rsmall proportion of grid operations. It has very specific requirements that aren't available everywhere. It's not an end-all solution for energy storage.

Not the parent, but feel compelled to clarify the physics here. Delta E= force * distance always holds. This is the same physics of a car breaking or a jet accelerating.

However a more general formula would be the integral of net force over distance.

Yes, I was just suggesting that force times distance is not relevant to energy storage as gravitational potential unless the distance is vertical.

Gravitation is not the only force.

Even without local "freshman" classes, you may look it up in any dictionary. Or, just stop pretending.

I understand gravitation isn't the only force... how are you proposing to store energy? Other options (beside pumped hydro as gravitational potential energy storage) that come to mind are flywheels, springs, or batteries .... all of these technologies have existed for more than 100 years, and batteries are the only ones currently growing in usage - there's a good reason for that.

Batteries are being used primarily in electric vehicles, for, as you say, good reasons, and for domestic backup. For bulk utility storage, batteries are the most expensive choice, although battery cost is still falling fast and numerous utility-adapted chemistries are competing.

F may be water pressure, as in pumped hydro (which is growing) using elevated or underground reservoirs, or air pressure, as in CAES underground or underwater compressed air, or buoyancy using sea-floor pulleys and floats. No doubt as a soon-to-be Licensed Professional Engineer you will soon be able to think of other persistent forces.

Springs and flywheels will not be used for bulk utility-scale storage.

Generally, utilities will use what is cheap and reliable at the time they build it. Building storage before you have enough spare renewable capacity to charge it would be a bad misallocation of capital

Anhydrous ammonia will not be the cheapest medium, but has advantages of transportability and fantastic usefulness. Any unused overbuilt capacity will be put to work synthesizing for sale.

What do the values of E, F, and x even stand for? Googling this yields no related results [1]. Presumably F and x stand for the energy output of a storage system and the duration that system is online, respectively. But simply stating that equation is pointless, unless you actually give a plan to deliver on appropriate values of F and x. It's about as inane as saying "E + MC^2 so let's just build fusion and be done with it."

1. https://google.gprivate.com/search.php?search?q=E%20=%20Fx%2...

You really are fooling no one. Why maintain the imposture? Are you not embarrassed at being called out on falsehoods each time you trot them out again?

For the third time, what do F, E, and x stand for? Are you not embarrassed about telling people to go back to their physics textbook when the equation you're writing has nothing to do with energy storage?

You still fool no one.

Then what will be used for grid-scale storage if not batteries and hydroelectricity?

> And as has been pointed out numerous times, no existing alpine lake is needed for hydro storage. And, the site does not need substantial "transportation infrastructure". Dozens of hydro dams, still in use, were built in California's Sierra Nevada mountains in the 1920s via roads a car cannot use.

Such as? How did they get heavy machinery to these dams to build them? All of the dams I can find like the Shasta dam, Orville dam, etc are in fact close to major transportation infrastructure.

The Sabatier process has significant blockers to actually being used: First, it needs a source of carbon dioxide, and the small concentration of it in he atmosphere is insufficient. Biofuels could be used for this, but they aren't produced in sufficient quantities. Second, it needs a source of hydrogen. Almost all hydrogen produced today is done through steam reformation, which emits carbon dioxide. Electrolysis accounts for a slim minority of hydrogen produced today, mainly due to inefficiency and issues with electrodes corroding. Nobody is operating commercial power to gas storage facility, it's only prototypes.

Commercial power-to-gas facilities are in operation in Germany, but large scale investments make little sense right now. The money is better spend in increasing the supply of renewable energy, or electrifying things that currently burn fossil fuels. Days where we have too much renewable energy are very rare still. It would be a waste to turn it into Hydrogen.

> Commercial power-to-gas facilities are in operation in Germany

Source? I'm only aware of pilot programs in Japan and Germany, not commercial operators.

Interesting. Though the lack of any cost estimate for this 1 MW facility does not inspire confidence.

Yes, and in 1950, no nuclear power plants operating; therefore nuclear power is impossible.

Who do you imagine you are fooling?

Disingenuity is deceptive everywhere it appears. Know that you are not fooling anybody.

I agree: nobody is fooled by your baseless claims that we can build dams where there's no transportation infrastructure. How does heavy machinery get to the site? How does the concrete get poured?

You insist the dams high in the Sierra Nevada range of California don't exist? You choose a strange hill to die on: anybody can see them in Google Maps satellite view.

They are not generally made of concrete, not being deep enough to need it. Their high pressure is confined in the penstock well downslope.

Again, just name three that aren't accessible by road or rail. If they're so easy to spot on Google maps, it should be trivial for you to find them.

Nice try. But I will not be wasting more time on your behalf.

Earlier you claimed it was trivial to find these inaccessible dams. You took the time to respond to my comment, and could have easily taken the trivial step of finding a few of these dams but curiously chose not to. Or, maybe these dams don't exist.

No such inaccessible dams exist, and if they do they hold an inconsequential amount of hydroelectric energy. Just exercise a modest amount of reasoning: no transportation infrastructure means all work is done by hand and all material transported manually as well.

Pre industrial dams did exist, but they were very shallow and used for irrigation rather than power. Moving enough earth and concrete to make a usable gradient is not possible without heavy machinery.

Pointing to one or two current storage technologies as evidence that the problem is fundamentally unsolvable is quite a logical leap.

Can we apply the same reasoning and conclude that because existing nuclear reactors are inadequate, no possible future nuclear reactors can be adequate?

Why does pumped hydro have to be close to transportation infrastructure, btw? Can one not build roads or rail lines?

The point is that no existing storage system is sufficient and thus solar and wind is really solar, wind, and fossil fuels. And nuclear power is indeed sufficient. They can indeed modulate power output, and we have the capacity to build them at the required scale. Some countries already have, like France.

> Why does pumped hydro have to be close to transportation infrastructure, btw? Can one not build roads or rail lines?

You can, but the more remote the build site the more expensive it becomes.

Current nuclear technology isn't sufficient either. A world powered by nuclear burner reactors runs out of uranium very quickly. Breeder reactors or seawater uranium extraction would be needed, and neither of these are "existing" in the sense you're using for storage.

This is incorrect, even existing supplies with no different form of extraction would last over 200 years: https://www.scientificamerican.com/article/how-long-will-glo...

Nuclear seawater extraction is already conducted, at a price of about $200 per pound [1]. Raw fuel extraction is a small portion of nuclear's cost (enrichment is a much bigger portion) so this is not a significant cost increase.

1. https://www.forbes.com/sites/jamesconca/2016/07/01/uranium-s...

200 years at today's consumption rate.

To power the world with nuclear would require many more reactors. Current world average primary energy consumption is 18 TW, which is 6000 3 GWth reactors. That's an order of magnitude more than currently are in operation. Add in demand growth from industrializing countries and the uranium would last maybe a decade.

Uranium availability is not an immediate problem if you assume nuclear remains a sideshow on the global energy stage. That's to assume nuclear is neither needed nor particularly useful for addressing global warming. Is that what you're assuming?

Did you read the article?

> However, seawater concentrations of uranium are controlled by steady-state, or pseudo-equilibrium, chemical reactions between waters and rocks on the Earth, both in the ocean and on land. And those rocks contain 100 trillion tons of uranium. So whenever uranium is extracted from seawater, more is leached from rocks to replace it, to the same concentration. It is impossible for humans to extract enough uranium over the next billion years to lower the overall seawater concentrations of uranium, even if nuclear provided 100% of our energy and our species lasted a billion years

Yes, I did read it. Did you lose track of what I said? I'll help by quoting myself:

"Current nuclear technology isn't sufficient either. A world powered by nuclear burner reactors runs out of uranium very quickly. Breeder reactors or seawater uranium extraction would be needed, and neither of these are "existing" in the sense you're using for storage" (emphasis added)

So, your comment about seawater there doesn't contradict what I wrote at all.

Again, from the same article:

> And these advances by PNNL and ORNL have reduced the cost by a factor of four in just five years. But it’s still over $200/lb of U3O8, twice as much as it needs to be to replace mining uranium ore.

> Fortunately, the cost of uranium is a small percentage of the cost of nuclear fuel, which is itself a small percentage of the cost of nuclear power. Over the last twenty years, uranium spot prices have varied between $10 and $120/lb of U3O8, mainly from changes in the availability of weapons-grade uranium to blend down to make reactor fuel.

> So as the cost of extracting U from seawater falls to below $100/lb, it will become a commercially viable alternative to mining new uranium ore. But even at $200/lb of U3O8, it doesn’t add more than a small fraction of a cent per kWh to the cost of nuclear power.

This is technology that actually has a demonstrated cost. Moreover it doesn't need to get cheaper at scale since raw extraction is such a small portion of nuclear power's cost. It's not like synthetic methane or hydrogen storage where it's all white papers promising cheap cost, but not actually delivering any storage systems at that cost.

Yes, and none of that is demonstrated, in the sense you seem to demand for renewables and storage. Lab exercises are smaller than what would happen in the field by many orders of magnitude and are happening in idealized conditions. The cost estimates are aspirational. This hypocrisy of yours is what I've been pointing out.

Extracting uranium from seawater on the scale needed to fuel burner reactors requires massive engineering. The estimate I've seen is that fueling one 1 GWe burner reactor takes a seafloor uranium absorption field (suspended in a strong ocean current; if you have to pump the seawater yourself it's already too expensive) of 170 square kilometers. The power/area is already much lower than the time-averaged output from PV.

Extrapolating from the lab bench to 170 sq. kilometers (x 6000 for the number of reactors needed to power a nuclear world) is a far larger stretch than extrapolating renewables and storage to what they would need. Your selective doubt is not being driven by any honest impulse.

> Yes, and none of that is demonstrated, in the sense you seem to demand for renewables and storage

All I demand is that people deliver at the specified cost. Not, for example, a prototype with unspecified cost or a pilot program with much higher cost to and promises that it'll get cheaper at scale.

> Extrapolating from the lab bench to 170 sq. kilometers (x 6000 for the number of reactors needed to power a nuclear world) is a far larger stretch than extrapolating renewables and storage to what they would need. Your selective doubt is not being driven by any honest impulse.

I could say the same about you. Nobody is seriously considering pumping seawater to filter uranium. This is a totally bad faith argument.

And you give this estimate of 170 without actually giving a source for it nor specifying details like how far apart the buoys are spaced, or if reprocessing is used (which cuts down fuel use by more than an order of magnitude).