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Comment by illiarian | Hacker News Reader

That is a "model" tat is very handwavy about a lot of things.

36% battery power capable of sustaining Hawaii for 11 hours. 4% is "flexible gas" from "carbon-neutral synthetic fuels" that will be produced using "excess renewable energy", etc.

No numbers except "flexible solution is 68% cheaper than just overbuilding renewables". "All technology options have been priced at their expected costs at year 2030."

These are not calculations. These are marketing materials for Wärtsilä

Edit:

There are some interesting things though. For example, if you click on solar, they show that you need 3.4x installed solar capacity compared to peak load. And (emphaisis mine): "Because the sun is only shining for part of the day, solar panels can on average over the whole day produce energy at maximum of around 25% of their installed capacity"

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I know xkcd thinks we should celebrate the 10,000 people learning something new each day, but I wish people would hold back from having strong opinions on renewables if facts like the sun not shining at night are blowing their minds.

> if facts like the sun not shining at night are blowing their minds.

If that was a jab at me it's misdirected. In the comment you originally replied to I literally talk about overbuilding.

And yet very few if any renewables proponents talk about the absolute requirement to overbuild, and the cost.

Oh they absolutely do. "did you know you need to overbuild?" is well up there with "did you know the sun doesnt shine at night?"

A solar farm with a nameplate capacity of 1 GW is about 5% of the cost of a 1GW nuclear plant. The need for overbuilding pushes the price up to roughly 20% of the cost.

Adding all the necessary storage to provide peaking can push it all the way up to ~80% of the cost of a nuclear power station.

Storage is kind of a moot point anyway these days. Most grids don't even have enough nameplate capacity to supply 100% of demand for even 1 day a year. With a few exceptions every GWh produced at any time by any solar panel or turbine - is just a GWh of gas that can be burned some other day.

> "did you know you need to overbuild?" is well up there with "did you know the sun doesnt shine at night?"

Of course it isn't. Almost none of the renewal proponents take those costs into account.

> A solar farm with a nameplate capacity of 1 GW is about 5% of the cost of a 1GW nuclear plant. The need for overbuilding pushes the price up to roughly 20% of the cost.

Are you sure you added all the requirements to the picture?

E.g. Two weeks ago there was a quiet night in Germany. Solar was at 0%. Wind was at 5%. You'd need to overbuild wind 400% just to compensate for some of the power needed then.

> Adding all the necessary storage to provide peaking can push it all the way up to ~80% of the cost of a nuclear power station.

Ah yes. The magical non-existent storage.

> Storage is kind of a moot point anyway these days. Most grids don't even have enough nameplate capacity to supply 100% of demand for even 1 day a year.

Funny how storage is moot, so Germany is burning coal during the night to compensate for solar, and for wind on quite nights, because they shut down their nuclear power plants.

I linked you to a comprehensive study that explicitly discussed overbuild and storage to meet both diurnal and seasonal variation, for 147 regions around the globe.

There are many interesting take aways from that, but the one you quoted, and added your own emphasis to, is that solar has a 25% capacity factor.

> Because the sun is only shining for part of the day, solar panels can on average over the whole day produce energy at maximum of around 25% of their installed capacity"

Why did you find this interesting if you are aware that the sun doesn't shine constantly all day and night?

> There are many interesting take aways from that, but the one you quoted, and added your own emphasis to, is that solar has a 25% capacity factor.

Yes, I did. So?

> Why did you find this interesting if you are aware that the sun doesn't shine constantly all day and night?

Whatever you're trying to ascribe to me exists only in your imagination.

Let me quote my comment again:

" And I'd love to see all the calculations [for the cost] that include the need to overbuild, the need for storage etc."

Yes. You linked the study. It does quote the need to overbuild solar by a factor of 3.4. What's the cost?

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