I heard recently of a study that found 2-4 hours is sufficient along with an interconnected grid.

I wouldn't be willing to bet my economy on that.

That’s BS. For several reasons.

1) grid connections fail sometimes. Do you want people freezing to death in NY when the Texas interconnect goes down for a day or two, or vice versa?

2) regional storms (Florida hurricanes, NY ice storms, etc), periodically take out large swathes of grid and would take out grid interconnections too.

Currently, the scope of the impact of these things is quite limited because everyone also has regional capacity.

But if you’re in a giant storm, you’d be super screwed and the whole region would be blacked out for awhile, because renewables also are impacted by these storms - far more than a gas turbine, for instance.

And that’s not even counting demand spikes and the like due to weather issues (longer than usual hot or cold, etc.)

> Do you want people freezing to death

Have you ever had a useful discussion after accusing the other side of wanting to kill people?

It is a legitimate risk of your proposal.

Did you reply to the correct comment? I didn't propose anything.

Nuclear power plants also have a low probability catastrophic failure mode. If it was a risk we’d engineer to mitigate it.

The referenced plan was to explicitly not do so. And ‘happens every decade or so in the US’ is a lot more frequent than meltdowns, and not very far down the tail as far as such things go.

Where is the accusation exactly?

I was pointing out the real risks involved, and asking them if they were ok with them. Statistically, such a plan would result in that outcome pretty quickly.

Personally I just assumed they had no idea, not that they didn’t care.

Roughly 0% of experts behind more renewables and storage agree with you. But maybe you don't realize that, given that you'd drive them away with this style of argument.

Really, 100% of experts think we need only a few hours of storage and reserve if we connect all the grids?

Cites appreciated! I currently see zero.

No, no one said that but you.

It was literally the comment I originally replied to.

You replied to

> I heard recently of a study that found 2-4 hours is sufficient along with an interconnected grid.

That, literally, is not the same as:

> Really, 100% of experts think we need only a few hours of storage and reserve if we connect all the grids?

Again, you're not going to have a good conversation if you keep on doing this.

I take it I hurt your feelings?

Tell me where those two statements you quoted are materially different (keeping in mind I was including the 0% of experts reply later), if you’d like to continue. Or don’t.

I don't see the difference either*. I would also appreciate you elaborating.

* The parts describing the grid look the same to me, and the percent of experts came from you, when you said 0% of experts agreed with their skepticism.

The hydrogen storage facility at Delta Utah has enough space in the salt formation for 100 caverns, each storing 150 GWh of energy. That's about 30 hours worth (well, maybe less, if that 150 GWh is before conversion to electrical energy, but still this is just one location.)

1) That doesn't actually exist yet. 2) You would need a huge number of generators to actually generate enough electricity to power the entire US.

Combined cycle power plants cost about $1/W; simple cycle, about $0.50/W. Combustion turbines are cheap. A nuclear plant, $10/W.

We could back up the entire damned grid with these things at a cost small compared to the cost of powering that grid with nuclear power plants.

As for "not actually existing yet", that's not anything close to a valid argument. Also, hydrogen storage doesn't require anything new -- all the component technologies exist, they just have to be integrated. This is the easiest and surest kind of innovation. It would be nice if higher demand drive electrolysers down their experience curve some more, I will admit. Cheaper is always nice.

"We could back up the entire damned grid with these things at a cost small compared to the cost of powering that grid with nuclear power plants."

I really want this to be true, I just don't think it is.

How hard is it to compare the numbers "1" and "10"?

Surprisingly hard if the confidence intervals are wide enough.

They're not? I mean, combined cycle plants have been built out the wazoo, so there's good data on that (replacing natural gas with hydrogen causes only minor changes, mostly in the combustor, and there are already industrial combustion turbines burning fuel gases that are mostly hydrogen.) Cost data on recent nuclear builds in the west are also widely available.

I suppose you may be meaning there's no good upper bound on how bad the expected unexpected cost overruns in nuclear can be.

I mean I don't have any confidence your numbers are correct.

The cost of combustion turbine power plants is well established since so many have been built. The cost of nuclear plants built recently in the west is also readily available.

Given that, it gives me pause that you don't actually know that information, given how eager you are to represent your "knowledge" on this subject.

The costs of creating 100 of those hydrogen storage caverns is completely unknown. You also have to add the cost of power lines to distribute the power to the rest of the country.

What? Creation of storage caverns is certainly well costed, because that's a standard way natural gas is stored. There are 36 such storage caverns for natural gas in the US. The estimated per energy capacity cost of creating such caverns is as little as $1/kWh (when storing hydrogen).

Hydrogen could also be stored in aquifers and depleted natural gas fields, just as natural gas is stored in those.

What will the leakage rate be? Hydrogen leaks through everything.

Hydrogen has already been stored in underground caverns, so it's clearly acceptable.

Geological storage like this involves very thick layers (hundreds or thousands of feet), so the leakage will be low in any case. If geological formations can trap methane for millions of years, they can trap hydrogen for much shorter times.