Comment by adev_ | Hacker News Reader

Comment by adev_ | Hacker News Reader

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> it's easy to see that even we assume 50% curtailment rate,

It is now 07h00 in Portugal.

- Solar production is reduced to 0% because it is night time. Like it is 30% of the time.

- Wind is not blowing much. Wind production is at 3.14% of its total capacity.

To compensate that, 29% of the production is guarantee by Gas powerplant. The rest from Hydro.

To compensate its high Hydro consumption, Portugal is also doing Hydro storage for around 500 MW by Night using electricity imported from Spain. Spanish Electricity is produced around 25% from Gas, which makes the entire operation looks pretty much like Greenwashing.

The situation is not exceptional. It can in fact happen for weeks when an heavy depression exist in northern Atlantic.

So please, tell me again: How easy will it be to achieve 100% renewable we assume 50% curtailment rate ?

Shall Portugal increase its Wind capacity again by 20x ?

Can Hydro storage powered by Gas powerplants ever be considered "Green" ?

Or Shall we maybe rely on future magical Hydrogen electrolyser that do not exist yet to solve 22 GW of coal power consumption like Germany ?

Very simply - vastly increase hydro generation capacity by adding extra turbines to existing hydro powerplants. You can't increase overall amounts of electricity produced this way because water in dams is finite, but you can increase max power output when needed. This costs a tiny amount compared to digging up dams themselves, displacing businesses and people on the lands to be flooded, buying up land etc. because the footprint of the hydro powerplant doesn't change.

In some countries that's a problem because they don't have enough water. Portugal is lucky with that. Water in dams provides seasonal storage of a sort (even if it's never literally pumped up - just used only when necessary, on a high throughput if need be).

It will also mean that at daytime and overnight when wind is strong, hydro plants will completely stop.

...In fact, that seems already done. Portugal has 7.6GW of hydro capacity, up from 5GW in 2008. This allows for peak hydro production to cover 1.37 of average and almost entirety of peak electricity consumption in the country. So the answer is very trivial: "when situations like today happen, just use hydro, and don't use hydro in other situations when either wind or solar are available".

You build something like 3x peak demand and produce hydrogen or ammonia while you have a surplus so that you can burn it while the sun doesn't shine and the wind doesn't blow or use it as feedstock for your industrial processes. Industrial scale hydrogen electrolyzers exist, we just need to build more of them once we have a steady electricity surplus that allows us to run them economically.

And that is what you qualify "easy" ?

Replacing 30% of a country grid capacity by an unproven technology never tested at scale. Associated with an hydrogen storage capacity (which we already struggle to do in labs and in the rocket industry) large enough to substain weeks of productions never also not tested at scale is easy ?

All of that should also be cost efficient right ?

And if I follow your initial post, it should be solved in the incoming years right ?

You see, that summarize quite a lot of my problems with the "all renewable evangelism".

It's "easy" in the sense that we know what to do and have the technology, we just need to pay for it. It's easy in the same way going 100% nuclear would be.

Hydrogen can be stored in underground caverns, nobody stores large quantities liquefied like you would in a lab or a rocket. See for example https://www.lindehydrogen.com/technology/hydrogen-storage

Large parts of our natgas infra can be refitted for hydrogen with modest investment.

Every single energy thread in HN ends like this. Renewable fanatics get backed into a corner when they realize that it is impossible to run a grid on solar and wind alone. Then they start talking about things that currently cannot account for even 0.001% of our global energy storage needs, like hydrogen or batteries.

Backed into a corner? This thread basically started with "Portugal ran on 100% renewables"... Sobat least for one point in time, it is possible.

There are two options now: Take it from there and figure out options to make that one point in time sustainable all the time (requires real engineering and creativity, and time and money). Or throw our hands up, blame environmentalists for shuting down nuclear plants (which wasn't always environmentalists, nor did we ever have enough nuclear plants to begin with). Guess which approach gives us a way forward?

> Backed into a corner? This thread basically started with "Portugal ran on 100% renewables"... Sobat least for one point in time, it is possible.

Sure, but that's not sustainable, as the numbers on the parent comment clearly indicate. From that perspective, what gives us a way forward is acknowledging that headlines such as these are meaningless in the grand scheme of things, and trying to design an energy strategy that is compatible with the facts at hand.

This strategy already exists so: more renewables, heat pumps for heating, EVs, green hydrogen, flatten peak demand by making industrial demand more flexible. That strategy actually does work, it requires a ton of investment, and time, to scale so. Throw in existing nuclear as stop gap solution.

Besides being contrarian, which I get because I have the same tendencies, what would be your alternative? Not doing anything is obviously bad, new nuclear power plants take too long to build and are too expensive (all numbers prove that). So? Any other ideas?

Well, but how much energy storage do you really need if, say, renewables account for 5x or even 10x peak demand? If prices keep going down, I don't see why that wouldn't be possible.

> Then they start talking about things that currently cannot account for even 0.001% of our global energy storage needs

Not currently, but who's to say that it won't be possible to scale out manufacturing capacity for the technologies that we'll need? A couple of decades ago, EV production and EV charging networks basically did not exist, so by the same reasoning you'd be saying that it wouldn't be possible to have them.

But look where we are now.

Furthermore, the space of possibly feasible ideas/technologies is gigantic, you're just lacking in imagination. For starters, we haven't yet explored my idea:

1. Turn gym equipment into energy-generating devices.

2. Mandatory gym time by law for every able-bodied man and woman.

Solve the renewable problem and health/obesity problems at the same time. Boom.

If that's not enough:

3. Mandatory gym time also for pets and farm animals.

4. Install wind turbines on airplanes (deployed only when descending).

5. Install boat engines on floating wind turbines and remotely navigate them into hurricanes (imagine all that wind energy we're currently wasting!).

6. And if that's not enough, let's start constructing a Dyson sphere already. We already know how to build space rockets. So what's taking us so long? Less talk, more action.

And that's just the ideas that I, a layman, have come up with. So imagine what the experts could think of.

Also, peak demand isn't a natural law. When prices change, demand will. And it does already for close to ten years now for the important consumers in the industry. Make it profitable enough for those to move their demand, and they will.

Batteries handle considerably more than 0.001% of the grid in California, and they are buying large scale battery installations like a drunken environmentalist. And the batteries are getting cheaper.

https://www.scientificamerican.com/article/u-s-battery-insta...

That is from 2022. From what I could gleam from a paywalled Bloomberg article, 2023 continued the growth curve.

Solar plus batteries are just cheaper and faster than nuclear. The pro nuclear argument would have won if we had started the carbon burn shutdown 20 years ago but they snoozed while the mad environmentalists successfully pushed solar and cell phones pushed batteries into economic dominance.

In 20y we'll have much more solar energy produced than we could use.

"Just"

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