[bryanlarsen]

> You need both

Why do you need both? It's possible to get 99.99% reliability with wind & solar & batteries & weather modelling. There are multiple ways to handle a week long dankelflaute without nuclear: overbuilding, continental scale distribution, lots of batteries, etc. All are cheaper than nuclear.

It's also virtually impossible to get more than 99.99% reliability out of any grid, even a nuclear dominated one. Local distribution has many single points of failure.

[zchrykng]

How much do those batteries cost and can they supply power for multiple days or a season if your renewable sources aren't providing like normal?

Not to mention the environmental damage from producing and disposing of batteries.

[tcfhgj]

I agree, there are better options for mass scale long term energy storage than batteries, e.g. (green) hydrogen, methane

[bryanlarsen]

Pumped hydro is currently the cheapest long term energy storage by a significant amount.

[tcfhgj]

not so cheap anymore when you want to add lot's of storage capacity

[bryanlarsen]

That's exactly when pumped hydro shines. Increasing the storage reservoir capacity is cheap. It's the turbines and infrastructure that's expensive, but that doesn't change if you're only increasing the capacity.

[tcfhgj]

All the cheap storage reservoir capacity is already used - from where are you going to get more?

[well_ackshually]

"Why do you need both, it's possible with technologies we don't have at scales we don't control with predictions weeks ahead on a rapidly changing and unpredictable weather model"

Yeah, uh, I'm going to go with the "building a nuclear plant is the safest solution" answer, thanks. Technosolutionism is fun up to a certain point.

>It's possible to get 99.99% reliability [...] It's also virtually impossible to get more than 99.99% reliability out of any grid

Notwithstanding the fact that lol you're happily saying that you're perfectly fine you get 1 hour of complete downtime every year, which fucks over many industries and services, you're ignoring multiple facts: 1/ to ensure safety, that means rolling brownouts when you're at 95% capacity, great solution, 2/ 99.99% works exactly like it does in software: you don't get tiny seconds long drops, you get gigantic, energy grid collapsing catastrophic failures, that are impossible to restart, grid sync because every renewable island is isolated.

>It's also virtually impossible to get more than 99.99% reliability

What kind of incompetent country are you living in? I have had exactly ZERO minutes of power outages for the past 5 years. I'll be generous and include the 30 minutes of downtime for maintenance. The country wide average blackout time is 2m30s, .43 power cuts / person / year. That's 99.996% stability country wide, and that's heavily weighted down by the places that get fucked by a tree collapsing on a transformer station

[MakersF]

The marginal cost of batteries grows more than linearly.

When batteries are covering 0% of the need, the marginally added battery cycles many times, so the cost is spread over many kwh produced.

When you add batteries to go from 99.98 to 99.99, the batteries cycle only for that 0.01, so the same cost to build them is spread over a much fewer kwh, making each kwh produced a lot more expensive.

Seasonal storage is madness: you charge once and discharge once per year. Pay 100$/kwh to install it, discharge 20 times (20 years, a 5% payback time, which is a bad investment), and you're paying those kwh a 5$/kwh premium on top of the cost of buying the discharged power. If the battery is instead installed to shift the production from 12.00 to 18.00, it cycles 365 times a year, so in 20 years the premium is 0.01$/kwh.

So nucleare doesn't compete with the first 40% of penetration of renewables and the first 30% of battery, it competes with the last 10%, which is still needed to get to 0.

[bryanlarsen]

Per Ember Energy reports, a cost optimal new build grid is between 90% - 97% solar/wind/battery, and between 3% to 10% gas peaker depending on how much sun/wind your locale gets.

But you can't replace the gas peaker with 3% or 10% nuclear because in essence that gas peaker is supplying 100% of the power 3% to 10% of the time.

So you'd have to build nuclear plants that can supply 100% of the power. But once you have that you might as well use nuclear power 100% of the time because the rest is irrelevant. But that's about as far from cost-optimal as you can get.

As you mentioned, using batteries for seasonal storage is madness. So to get to 100% carbon free you have at least 2 other options:

1. use a different form of seasonal storage. China is experimenting with this. In 2026 they will double the world's pumped hydro storage capacity. But doubling isn't a lot -- the world doesn't have much pumped hydro. But it does mean they might start doing it at China scale in a few years.

2. Overbuild to avoid the need for seasonal storage. Solar works on cloudy days and in the winter. It just doesn't work very well. So you need a lot of it. Which is expensive, but still a heck of a lot cheaper than batteries for seasonal storage.

In reality, most places will probably say that 95% or 99% carbon reduction is good enough and keep their backup natural gas generators around for the occasional dankelflaute.

[eldaisfish]

every single one of Ember's analyses are based on historical situations. That is certainly useful, and serves to demonstrate an important point - that wind and solar make economic sense.

There is not a single analysis out there that tackles the twin problems of meeting growing electricity demand with a power source that depends on an uncertain and changing climate.

You say "occasional" dunkelflaute, but we have no idea whether occasional is once a season or once a decade.

This is exactly where nuclear shines, because although it is expensive, it insulates a country against the vagaries of external forces. Whether or not that guarantee is worth the price tag is the question a lot of governments are grappling with and they mostly seem to agree that the value is indeed worth the cost.

[bryanlarsen]

> You say "occasional" dunkelflaute, but we have no idea whether occasional is once a season or once a decade.

Yes, these are things we know with a high degree of statistical confidence. Many locations have hundreds of years of hourly weather records.

We know that Europe has never had an hour where there wasn't significant sun or significant wind somewhere on the continent any hour in the past 30+ years. The same can be said for North America, and Asia.

[eldaisfish]

way to miss the point.

What use is hundreds of hours of weather records when the climate is changing in ways we do not yet understand?

"somewhere" on the continent being windy is useless unless we have the transmission capacity to move that much power across thousands of kilometres. See also what just happened in australia last week - nearly 40% of the country stuck with very low wind speeds for nearly a week. What then?

[dalyons]

They mostly don’t seem to agree, as exhibited by the fact that virtually none of them are breaking ground on new nukes.