[ffsm8]

Tbf, solar has gotten so much more effective/cost efficient in the last 12-24 months that it's beating pretty much everything aside from hydro in the cost efficiency department at this point - including (most of) northern Europe and Canada.

Most data you find will be using data that's massively out of date and be off by at least 2x though...

I had another facepalm moment when I read about EU planning to go nuclear again. That would've been amazing and smart in 2015 - but now? Yeah, it's dumb af. And that's coming from a German living at the northern end of the country.

[Moldoteck]

Germany spends 10x more than france on transmission and curtailment each year. Households have highest prices in EU per Eurostat despite EEG subsidies. Even if everything goes well gas expansion is still required to firm renewables. All this while it still burns coal and gas.

Going nuclear was sane in the past and sane now. If Germany wants to prove expanding nuclear is dumb it should try first to have lower annual emissions, while spending less than double the cost of entire french fleet.

France is the biggest winner in EU- it'll build both nuclear and renewables achieving deep decarbonization

[mastermage]

EEG Subsidies no longer exist. Germany's high electricity price is due to the weird af Laws on Renewables, terrible planning, and well Gas Power, which is just expensive as shit.

[Moldoteck]

eeg still exists. It just moved to state expenditure when before it was paid directly. "weird af Laws on Renewables" - which laws? Gas firming was planned long time ago and mentioned even by fraunhofer

[mastermage]

Specifically alot of the laws on Windpower. Where it has to be amount x away from any populated place. Meaning there is only something like 0.1% of the area of Germany where you would be allowed to built Windparks.

My bad on the EEG i thought that stopped since I do not pay it anymore directly.

[Moldoteck]

I doubt wind laws expansion makes it that expensive. Laws were recently liberalized anyway.

But there are many more cost factors. With co2 tax, gas and coal firming are getting very expensive. Add to that massive transmission and distribution expansion/upgrades costs for distributed grid, add massive curtailment costs and you get what you get

[mono442]

Can batteries store enough energy for dunkelflaute in winter? I don't think it's possible with the current technology.

[pfdietz]

Batteries are not appropriate for dealing with Dunkelflauten. There's very little energy flowing through there, so what you want to do is trade lower round trip efficiency for lower capex. The high capex of batteries is best amortized over many charge/discharge cycles, for example for daily storage.

[dalyons]

I mean, who cares? Fire up the gas plants in the one week a year you have weather anomalies. We’d still be 90+% carbon free which would be incredible. The last gap can be solved at a later point as technology evolves

[pfdietz]

And replacing the natural gas burned in those turbines with hydrogen won't be very expensive, since they will be used so infrequently. Storing energy as hydrogen is much cheaper than storing it in batteries, as measured by cost of storage of capacity.

[hunterpayne]

My friend, renewables only have a capacity factor of .1 (10%). That means those "gas plants" (really coal, and the worst quality coal on the planet too) are running 90% of the time. There is a reason why France's grid makes 7x the power for the same CO2 emissions as Germany.

[jondea]

A single energy source having a capacity factor of 10% does not imply that gas plants will have to run 90% of the time.

It ignores storage, over-provisioning, aggregation of uncorrelated sources etc.

Not to mention that wind typically has a much higher capacity factor than 10%.

I don't know what the true number is, but I think this is a low effort take.

[tialaramex]

Wind turbines across a whole region you'd be looking at 30% maybe 35% or even 40% if they're off-shore. Off-shore the winds aren't slowed by all the random structures humans build but also the turbines are much taller and as your elevation increases the reliability of the wind increases.

PV it varies by how far you are from the equator, 10% is realistic for a Northern country like the UK or Germany whereas in Africa you might see 25% or even 30%

[Moldoteck]

It's not. Germany would need an insane amount, about 3twh based on recent data and much more looking at 30y weather data

[marcosdumay]

Batteries can store as much energy as you are willing to buy.

[wolfhumble]

> I had another facepalm moment when I read about EU planning to go nuclear again. That would've been amazing and smart in 2015 - but now? Yeah, it's dumb af. And that's coming from a German living at the northern end of the country.

In 2015, Germany produced about 650 TWh of electricity. In 2025, it’s around 507 TWh, a drop of roughly 22–23%.

Consumption has also declined, mainly due to efficiency improvements, higher energy prices, and weaker industrial demand.

Per person, that’s about 7,900 kWh in 2015 vs ~6,000 kWh in 2025. France is at roughly 8,000 kWh per person today, so basically where Germany used to be.

This happened despite adding about 100 TWh from wind and solar combined over the same period.

Wind is still volatile and hasn’t really ramped much in recent years, while solar is growing steadily, but mostly helps in summer.

And that’s the core issue. Solar output in summer is roughly 3× higher than in winter, so just adding more solar doesn’t solve those cold, dark winter periods without massive storage or backup.

To get back to 2015 production levels of around 650 TWh, Germany would need to increase output by about 30%. With solar growing by roughly 13–14 TWh per year and wind not increasing much recently, that puts you close to a decade just to get back to where you were, while 2030 demand is already projected at 700–750 TWh.

Given that Germany still imports around 70% of its total energy, it’s hard to call it a “facepalm” to suggest nuclear as part of the mix.

Also worth noting that Germany is still slow on smart meter rollout, with only around 2% of metering points using smart metering systems so far. That limits how much consumers can respond to real-time prices. During tight periods, this can increase reliance on imports and contribute to higher prices in connected markets such as the Nordics.

[mastermage]

Wind has a problem in Germany thats true, but the problem is not volatility its the maddening regulations that basically only exist because nimbys do not want Windparks built anywhere.

[phtrivier]

What I'll watch which great interest is how big an improvement in interseason storage you need for the situation to flip on it's head entirely.

If sodium-ion, or some kind of thermal, or some kind of gravitationnal (except pumped hydro), or whatever techno comes up that makes it possible to handle this dunkleflaute thing (i learned that word today, love it already :) [1]), then Germany will already have the panels and windmills.

If for some reason, there is a great chemistry already advanced in the labs, is it possible that Germany buys a GWh battery before the first few EPR-2s come out of the ground ?

That's one hell of a bet to make. By refusing to reconsider nuclear, Germany is basically betting on some sort of breakthrough (or continued gas supply, which, well, is betting on geopolitics...)

So maybe "carving up mountains" isn't such a crazy plan, after all...

[1] https://en.wikipedia.org/wiki/Dunkelflaute