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131 points mg | 56 comments | | HN request time: 3.45s | source | bottom
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zizee ◴[] No.26598033[source]
I think the future will be robust national/international grids, with a mixture of storage options (batteries/pumped hydro) to smooth out the intermittent nature of wind and solar.

Cynics always talk about the amount of energy storage required for solar as if you need to store 24 hours of energy for solar/wind to be viable.

I'd like to see numbers on having 1 hour of storage for peak demand, a robust national grid, and appropriately provisioned and placed solar and wind, taking the duck curve into consideration.

replies(6): >>26598222 #>>26598329 #>>26598526 #>>26598746 #>>26599340 #>>26599508 #
1. manfredo ◴[] No.26598222[source]
Even achieving just one hour of storage globally amounts to 2.5 TWh of storage. By comparison the entire world produces ~300 GWh worth of lithium ion battery annually. That leaves geographically limited options like pumped hydroelectricity, and solutions not yet deployed at any significant scale like hydrogen fuel cells, synthetic methane, thermal batteries, flywheels, etc.

Realistically we should saturate daytime energy demand with solar, and if there aren't any scalable storage options by then switch gears and proceed with hydroelectric where it's viable and nuclear where it's not.

replies(7): >>26598287 #>>26598427 #>>26598481 #>>26598549 #>>26598594 #>>26598763 #>>26599062 #
2. nicoburns ◴[] No.26598287[source]
> Even achieving just one hour of storage globally amounts to 2.5 TWh of storage. By comparison the entire world produces ~300 GWh worth of lithium ion battery annually

... so if we could increase battery production by just 10x, then we could create an hours worth of storage every year. That seems... very doable.

replies(2): >>26598326 #>>26598345 #
3. thiht ◴[] No.26598326[source]
That sounds extremely expensive and not very green.
4. manfredo ◴[] No.26598345[source]
And then we'd have to continue that production for two and a half decades to get to 1 day of storage. And we'd also have to drastically increase our battery recycling capacity to match (remember most lithium ion batteries last 1000-2000 cycles).
replies(1): >>26598377 #
5. jeffbee ◴[] No.26598377{3}[source]
Nobody needs 1 full day of storage.
replies(2): >>26598416 #>>26599546 #
6. ch4s3 ◴[] No.26598416{4}[source]
One could imagine a series of cloudy windless days in the northern latitudes during the winter. Perhaps a large enough gird solves that problem? I have no clue.
replies(4): >>26598531 #>>26598608 #>>26599054 #>>26609437 #
7. pydry ◴[] No.26598481[source]
>Even achieving just one hour of storage globally amounts to 2.5 TWh of storage. By comparison the entire world produces ~300 GWh worth of lithium ion battery

What's the point of this comparison?

Lithium ion batteries are probably the least cost effective means of dealing with intermittency. It's also rare that the entire world is without wind and sun simultaneously.

In terms of cost:

Demand shaping < overproduction < pumped storage < < lithium ion batteries

replies(1): >>26598979 #
8. lutorm ◴[] No.26598531{5}[source]
But the key is that if you're averaging globally, the solar power probably doesn't change much. You'll need a way to transport the energy instead, obviously.
9. psadri ◴[] No.26598549[source]
We could use day time electricity to generate fuels to burn at night. As long as it’s net-zero wrt to CO2 emissions, it will be fine.
10. mgolawala ◴[] No.26598594[source]
Why would we use lithium ion batteries?

I would imagine the approach to store the energy would be to use the energy from solar panels to do work that can be used to produce electricity later.

For example, you could use solar energy to pump water back uphill to flow down through a hydro electric dam later.

Even if it isn't the most efficient, in the long run it would likely provide the best scalability and least long term environmental impact. Once you have the facility in place, the same water could be pumped uphill to flow back down a million times over with the only overhead replacing water lost through evaporation and maintaining the facility.

Am I missing something that makes such an approach unfeasible?

replies(2): >>26598735 #>>26598738 #
11. pfdietz ◴[] No.26598608{5}[source]
One would not use batteries for the "rare, but prolonged" storage use case. You'd want something with lower capital cost, even if it were much less efficient. For example: hydrogen burned in turbines.
replies(2): >>26598820 #>>26599302 #
12. kragen ◴[] No.26598735[source]
My comment at https://news.ycombinator.com/item?id=26597661 links to a number of overviews of the issue, including MacKay's chapter in which he covers pumped storage in about as much depth as you can possibly hope in a 20-page chapter aimed at a general audience. Go read it!
13. manfredo ◴[] No.26598738[source]
Hydroelectric storage is geographically dependent. You need the right topography and access to water. Likewise, hydroelectric storage takes a long time to build.
14. Qwertious ◴[] No.26598763[source]
>By comparison the entire world produces ~300 GWh worth of lithium ion battery annually.

And this will increase a hundredfold to make EV production possible.

That means that if 10% of production goes to stationary storage then within 10 years, we'll have 10 full global hours of storage.

If there's serious demand then the supply will scale up to create it.

Also, old EV batteries will provide plenty of extra stationary storage. Not to mention batteries still in EVs, in a pinch.

Realistically we won't throw insane amounts of storage at the problem. We'll make demand more flexible so it does work when electricity is cheap and eases off when it becomes more expensive.

For instance, something like heating: why store the electricity for heating? Wouldn't it make more sense for a house to have some form of heavily-insulated thermal mass that it can massively heat when electricity is dirt cheap, then tap into at midnight without drawing power? Storing heat is cheap, you just need a giant block of concrete with solid insulation. You don't need fancy nanoscale tech like with lithium-ion.

Even something like a kettle: the hot water taps you see at companies that are pre-heated. Have a home-version. Insulate the shit out of that and do 90% of the boiling with peak electricity.

And that's not even touching industrial power usage.

Trying to ape past systems that were based on flat electricity prices just seems like a failure of imagination. Of course it would be expensive, but why the heck would you even want to?

replies(2): >>26599031 #>>26605495 #
15. Manfredo_1 ◴[] No.26598820{6}[source]
Hydrogen storage remains in the prototyping phase. We have no significant amount of hydrogen grid storage. Like thermal batteries or synthetic methane, hydrogen represents a potential storage solution but not one that we know will scale and be effectively deployed at the scope required.

If we actually deploy 50 GWh of hydrogen storage, and demonstrate that it can cheaply and reliability be built at scale then your point would be valid. But until then, hydrogen represents a theoretical solution not an actual solution.

replies(2): >>26598873 #>>26605182 #
16. pfdietz ◴[] No.26598873{7}[source]
All the components of hydrogen, with the possible exception of low cost electrolyzers, don't need to be prototyped. It's existing technology. It's not like (say) molten salt reactors, in which fundamental development remains to be done.
replies(1): >>26598899 #
17. Manfredo_1 ◴[] No.26598899{8}[source]
Right, and what company can I call right now to install 50GWh of hydrogen storage?

It's existing technology, but it's a novel application of that technology. We haven't used hydrogen electrolysis as a form of grid storage before. And we certainly haven't used it for grid storage at the Terawatt hour scale. And that the scale we'll need to make wind and solar viable. 1 TWh isn't even 30 minutes of global electricity consumption.

replies(2): >>26598963 #>>26599089 #
18. pfdietz ◴[] No.26598963{9}[source]
50 GWh of hydrogen would fit in one salt cavern of the kind already made for natural gas. Any numbers of companies can solution mine those caverns for you; that technology is many decades old. I'd need more information about the rest of what you want, as that scales by power not by energy capacity.
replies(1): >>26599007 #
19. Manfredo_1 ◴[] No.26598979[source]
"Demand shaping" is a nice euphemism for energy shortages. And if we demand shaping we're just externalizing the cost to consumers that need to buy their own energy storage or change their energy usage patterns to accommodate the unreliable supply.

Overproduction helps but doesn't eliminate intermittency. And pumped hydroelectricity is geographically dependent. The irony is that most places with extensive hydroelectric storage potential don't need wind and solar in the first place because they get their energy from hydroelectric generation.

replies(4): >>26599023 #>>26599033 #>>26599617 #>>26601431 #
20. Manfredo_1 ◴[] No.26599007{10}[source]
And are we currently using any of these caverns for electrolysis and grid storage? All you said is that we have a big cavern that we could fill with hydrogen. I'm asking if anybody is actually building hydrogen grid storage at any significant scale. Are there any facilities that take in excess energy from renewables, turn it into hydrogen, and then turn that hydrogen back into electricity?

We both know the answer: there aren't any.

Back in the 1950s people thought nuclear power would be cheaper than fossil fuels. They thought it'd be effectively free. The energy density of uranium is so much better, so clearly generating electricity with it would be much cheaper. But actually deploying a technology at scale reveals more and more challenges.

Your proposal for hydrogen storage is in the same phase that nuclear power was in during the 1950s. A solution that exists on paper, but one that hasn't actually encountered and overcome the challenges of implementing it at scale. Same with thermal batteries, synthetic methane, and so on. These are proposals that haven't passed the test of actual implementation at scale.

replies(1): >>26599327 #
21. asdfasgasdgasdg ◴[] No.26599023{3}[source]
There is always a shortage of electricity. Someone could always use more if it were free to do so. Economics is the study of the allocation of resources in the face of scarcity -- that is, all allocation of resources except perhaps breathable air. There's no need for a euphemism here because limitations on the consumption of energy are ever-present -- demand shaping is simply about making the signal stronger.
replies(1): >>26599041 #
22. Symbiote ◴[] No.26599031[source]
The heater you describe is called a storage heater.

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

23. crummy ◴[] No.26599033{3}[source]
Isn't demand shaping things like discounts during certain periods? My electricity provider lets me set a 'free hour of power' every day, as long as that hour is off peak.
replies(1): >>26599050 #
24. Manfredo_1 ◴[] No.26599041{4}[source]
There are rarely shortages of electricity in the US. There were some in California during Covid, and the state had to do rolling blackouts. But no, there are rarely shortages of electricity.

Yes, someone could use more of it than we could supply. But they don't. The existing supply is sufficient to meet demand. And when demand changes, we are capable of increasing supply.

25. Manfredo_1 ◴[] No.26599050{4}[source]
Yes, those incentives exist to try and shape demand. But in practice, people rarely take advantage of them. And some things really can't be shaped. The pumps that deliver your water cannot have their demand shaped, unless you're willing to go without running water for some hours of the day.
replies(2): >>26599155 #>>26601771 #
26. acdha ◴[] No.26599054{5}[source]
That’s a problem if you’re an island isolated from everyone else, and you don’t have geothermal, hydroelectric, or nuclear options. The better question is how much capacity you’d need on a national grid to be able to handle large regional sags in production without endangering people.

As we recently saw with Texas’ catastrophic fossil fuel production failures the big problem is not the source but poor management and not being able to get help from the neighbors.

27. intrepidhero ◴[] No.26599062[source]
Let me introduce you to flow batteries. Lithium is a terrible choice for grid scale storage, except maybe as a secondary use of idle EVs.

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

28. Hypx ◴[] No.26599089{9}[source]
https://www.pv-magazine.com/2020/06/16/hydrogen-storage-in-s...

We could easily have Petawatt-hour scale hydrogen energy storage.

replies(1): >>26599131 #
29. Manfredo_1 ◴[] No.26599131{10}[source]
No, you have salt caverns with a volume sufficient to accommodate a lot of hydrogen. Actually implementing such a solution involves massive scale electrolysis, and either massive scales of oxidation cells or gas turbines designed to burn hydrogen. Neither of these things have been done at anything remotely close to the scale required to make renewables feasible.

Back in the 1950s people thought that nuclear power would be effectively free. But actually building it at scale exposed challenges of implementation that weren't foreseen. The cost of a system on paper and the cost after overcoming the challenges of actually building it are two very different things. For hydrogen storage, you only have the former.

replies(1): >>26599162 #
30. panarky ◴[] No.26599155{5}[source]
If we paid the true cost of peak power, it might be worth pumping water with off-peak power and storing it locally.
replies(1): >>26599542 #
31. Hypx ◴[] No.26599162{11}[source]
Those gas turbines you're referring to can simply be modified natural gas gas turbines. The only limiting factor would be electrolysis, but that is already something people are planning to build a lot of.

Nuclear's problem are fundamentally political in nature. If we really cared about green energy, nuclear power could easily be built out at scale.

replies(1): >>26599213 #
32. Manfredo_1 ◴[] No.26599213{12}[source]
No, hydrogen rapidly corrodes any metals that it comes into contact with. If they are interchangeable, expect drastically smaller service intervals.
replies(3): >>26599307 #>>26599329 #>>26600148 #
33. rhodozelia ◴[] No.26599302{6}[source]
Who pays for the shadow generation system that we keep perfectly maintained and ready to generate 100% of system demand on the 5 days stretch of cloudy windless days? This cost has to be added to the cost of building a 100% solar/wind system.

Nobody is arguing the solar and wind power isn’t cheap, but the cost of power on those cloudy windless weeks is going to be real high to make having all that standby generation around. It’s the cost to achieve the same reliability and 99% carbon free that is expensive.

Money is imaginary and global warming isn’t so let’s just print some bonds or move some numbers around in some database and build it all! - an electrical power engineer

replies(1): >>26599381 #
34. pfdietz ◴[] No.26599307{13}[source]
> No, hydrogen rapidly corrodes any metals that it comes into contact with.

The industries that manipulate tens of millions of tons of hydrogen each year would be astounded to hear this statement of yours. What are those facilities made of, unobtainium?

35. pfdietz ◴[] No.26599327{11}[source]
Dude. You are falling back to the "if it isn't already being done, it can't be done" argument. Please stop this foolishness.

Hydrogen is being stored in a few places. That the storage isn't larger isn't because of any technical obstacles, it's because there's no reason to store it now. In particular, when we can burn natural gas without CO2 charges, using the hydrogen for energy storage is pointless.

This doesn't mean hydrogen CAN'T be stored, it just means the market conditions for widespread adoption of an off-the-self technology aren't there yet.

replies(1): >>26599476 #
36. Hypx ◴[] No.26599329{13}[source]
A claim which simply isn't true. Only certain alloys have a problem with hydrogen. We've been using hydrogen in industry for decades and most of this problem has been solved.
replies(1): >>26599399 #
37. pfdietz ◴[] No.26599381{7}[source]
The cost will be there, but overall it looks like it will be cheaper than nuclear.
replies(1): >>26599598 #
38. Manfredo_1 ◴[] No.26599399{14}[source]
We've been using hydrogen in the chemical industry. We haven't been using hydrogen to drive combustion turbines very much, and even then it's in a mixture of natural gas.

Unfortunately, those alloys that experience embrittlement includes the ones used in steam turbines: https://www.sciencedirect.com/science/article/abs/pii/S09215...

39. Manfredo_1 ◴[] No.26599476{12}[source]
Storing hydrogen is only one piece of the puzzle. Yes, if you happen to live near an abandoned salt mine that's a convenient place to put a large quantity of hydrogen. That doesn't solve the problem of massive electrolysis facilities, and turbines that can burn hydrogen.

And it certainly doesn't answer the question of whether or not this represents a viable grid-storage solution, since we haven't built it at remotely close to the scale required.

It's not "if it isn't already being done, it can't be done"

It's "if it isn't already being done, it is extremely reckless to assume that it can be done cheaply at a massive scale".

Screw it, let's just use fusion. Nobody has actually built a fusion plant? Well, who cares if it hasn't already been done, that's a "foolish argument" in your own words. /s

replies(1): >>26599541 #
40. pfdietz ◴[] No.26599541{13}[source]
These are not abandoned salt mines, they are deliberately created caverns in salt domes. The cost of creating them is included in the capital cost ($1/kWh capacity).

Hydrogen could also be stored in depleted gas fields and in deep saline aquifers. The storage capacity available is more than adequate.

replies(1): >>26599719 #
41. Manfredo_1 ◴[] No.26599542{6}[source]
Then our transition to solar + wind needs to include the cost of installing a septic tank and water reservoir in every household. And a thermal battery for heating. And an electric battery for lighting. And all the other things we'll need to do to accommodate an unreliable energy grid.
42. Manfredo_1 ◴[] No.26599546{4}[source]
We'd actually need 3 weeks of storage to migrate to a fully renewable grid: https://pv-magazine-usa.com/2018/03/01/12-hours-energy-stora...
replies(1): >>26599637 #
43. rhodozelia ◴[] No.26599598{8}[source]
In British Columbia they are building a 1000 MW hydro plant that is going to cost 10-12 billion. Similar story at muskrat falls in Labrador.

Large projects are just expensive now. Nuclear would be competitive with either of these hydro projects.

replies(1): >>26599656 #
44. Qwertious ◴[] No.26599617{3}[source]
>to accommodate the unreliable supply.

You're conflating "expensive" with "unreliable". Even with infinite batteries, buying stored energy will always be more expensive than direct solar/wind.

45. Qwertious ◴[] No.26599637{5}[source]
From your own source:

"The solar heavy network wouldn’t need energy storage with an HVDC network."

So no, we wouldn't need that. HVDC would be far cheaper.

replies(1): >>26599659 #
46. pfdietz ◴[] No.26599656{9}[source]
That hydro project doesn't sound competitive.
replies(1): >>26599717 #
47. Manfredo_1 ◴[] No.26599659{6}[source]
A solar heavy network would still need 12 hours of storage to accommodate nighttime energy use. More actually, because of greater seasonal fluctuations further from the equator.

All of the Americas experience night time simultaneously for at least 8 hours a day. Even if we ran HVDC lines to the Sahara, there's still a period of time where most sunlight is shining on the pacific ocean.

replies(1): >>26619198 #
48. rhodozelia ◴[] No.26599717{10}[source]
I guess not, but when two or three projects come in at the 10 billion cad mark it’s a pretty good sign that’s our cost to build. Not necessarily unique to hydro - we might have high cost to build anything
49. Manfredo_1 ◴[] No.26599719{14}[source]
For the third time, storage is only one part of the puzzle. We also need a way to cheaply electrolyze water into hydrogen, compress it into the storage facility, and then use it to generate electricity. Nobody doubts that you can pump hydrogen into a big cave. What's dubious is transforming this into a usable energy-storage facility.

We haven't done this to provide 100 MWh of storage. How on earth can we be confident it'll be easy to provide 1 TWh of storage, or 10 TWh?

People mostly talk about lithium ion storage because that's what's actually available, besides geographically limited options like hydroelectricity. Until there's a company that's building dozens of gigawatt hours of hydrogen storage it's a moot point. It's a technology that exists the laboratory, not one that's commercially available.

50. Manfredo_1 ◴[] No.26600148{13}[source]
Most companies are targeting hydrogen gas turbines to be produced in 2030 or 2040: https://www.siemens-energy.com/global/en/news/magazine/2019/...

They aren't "off the shelf" technology yet.

51. pydry ◴[] No.26601431{3}[source]
>Demand shaping" is a nice euphemism for energy shortages.

It's a euphemism for storage heaters, storage air-conditioning, aluminium smelters that dial usage up and down and smart car chargers.

Lithium ion batteries are useful too, of course, but they cost more.

This is a problem where market based solutions shine. The only reason that fact isn't getting rammed down our throats by lobbyists is that the people who got religion about markets tended to be oil/gas people, who have since been thrashing the "renewables are unreliable" drum.

>Overproduction helps but doesn't eliminate intermittency.

Why should the goal be to eliminate it when we can adapt to it and thrive?

Personally, I'm more excited for applications of periodic free/-ve priced electricity than I am worried about shortages.

52. pydry ◴[] No.26601771{5}[source]
>in practice, people rarely take advantage of them

Overproduction is still not that common. These days wind and solar mostly just provide power that would have otherwise been produced by natural gas even when operating at peak capacity.

It is getting off the ground though. The UK has an energy tarriff popular with electric car owners for this reason. They can occasionally get paid to charge their cars. This type of thing will only become more common.

>And some things really can't be shaped.

Obviously not. Nonetheless pretending that all renewable intermittency has to be made up for with expensive lithium ion batteries is backwards thinking.

53. philipkglass ◴[] No.26605182{7}[source]
Hydrogen is stored underground in Texas salt formations at Clemens Dome, Moss Bluff, and Spindletop. The largest of them, Spindletop, was completed in 2017:

https://www.airliquide.com/sites/airliquide.com/files/2017/0...

This presentation says that the Spindletop hydrogen capacity is equivalent to ~120 GWh.

https://ukccsrc.ac.uk/wp-content/uploads/2020/05/John-Willia...

54. cmcnab ◴[] No.26605495[source]
I had a house for a time that had just what you describe: a concrete block thermal mass set in the foundation. There were ducts running through it as part of the forced-air system. During the days, especially sunny days, the block soaked up the excess heat and then radiated it back out during the night. It worked quite well; indoor temperatures stayed remarkably consistent. A company called Adirondack Alternate Energy were the architects. https://aaepassivesolar.com/low-energy.html
55. nicoburns ◴[] No.26609437{5}[source]
If we had smart metering, then we could simply restrict consumption in these (presumably rare) circumstances.
56. Qwertious ◴[] No.26619198{7}[source]
Yes, 100% solar makes no sense. Thankfully, we have other sources such as wind.

Also, if you can run HVDC to the Sahara you could run it to hydro plants, so I don't think that's a good hypothetical.

But mostly, talking about pure solar just makes no sense.