Hacker News Reader

Comment by inglor_cz | Hacker News Reader

Scaling is a problem.

How many batteries do you need to power, say, entire Scandinavia during winter? That would be a lot of lithium, btw.

"Dunkelflaute" periods when it is dark and no wind to run the wind turbines are common in northern winters, IIRC the longest one a few years ago was 12 days long.

Which means that in order to have a reasonable buffer against it, you would need enough batteries to supply the entire region for three weeks. Not going to happen, unless we discover some much more efficient class of batteries.

View on HN

Sodium batteries are cheaper for storage and does not require any rate/expensive minerals, just scaling up production. Then in Scandinavia the main problem in winter is heating and using heated water as a battery is already a thing. Then producing amonia or even carbon fuel from atmosphere for energy-dense storage will be viable option in 10-20 years. And of cause Norway and Sweden can have massive hydro for energy storage.

That 12 day event was a regional event in Germany, there was still lots of wind in the North Sea. And sun & wind didn't drop to 0, it dropped below 10%.

Dunkelflaute's are a German phenomenon: the standard pattern in most of the world is that the high pressure systems that suppress winds are generally sunny. And the high elevation areas in Germany are sunny during a dunkelflaute.

IOW, batteries aren't the only answer required to cover a dunkelflaute.

Hydrogen is one possibility for a 100% grid to cover Dunkelflauten and seasonal leveling (the former for wind, the latter for solar). To see the effects on overall cost per MWh, explore at https://model.energy/

Fission reactors in multiple European countries had to shut down due to heatwaves. And in Scandinavia (Sweden), they are "routinely" stopped for scheduled and most importantly unscheduled maintenance.

But those don't have scary sounding German names, I guess.

I don't find the word Dunkelflaute any more scary than the word Kindergarten, but I am used to speaking and reading German...

And you might have noticed me commenting on the need to shut down some reactors due to lack of water elsewhere.

boy am i tired of hearing that Dunkelflaute word as if its some kind of gotcha. Even ignoring the fact that you can continue to source power from other geographies during a localized phenomenon..... Just burn gas in peaker plants for the few days a year that this happens. That small amount of emissions wont matter for the next 50 years of decarbonization, after which we'll likely have plenty of other options.

The absolutism in all these arguments is so tiring, as if its not 100% perfect solution for 100% of every imaginable scenario than its no good. 95% reduction over a year would be astounding, we would have won the climate battle.

That's fine, but you need to include the cost of having barely-used gas peaker plants when calculating the cost of "renewables+storage". Laymen keep using arbitrary "marginal cost of solar with sun shining" to say "solar is cheaper than everything!". If it's true that capex of 80% gas peaker (and LNG storage and employees on standby and so on) + solar + wind + batteries is cheaper, then people should make that argument and provide the data.

The latest figures from ember etc are not only “sun shining”, they’re talking about 24hr firmed solar-storage costs, and they’re still mostly cheaper than fossil in most geos. It is true that we will have to pay for having gas fill the gaps - how much exactly is a very complicated function of market economics and real time power auctions. Depends on so many variables, how big is the shortfall, how long, what competition does the gas have locally and extra-geographically, many other things. For connected countries in Europe you are never going to get to a situation where you need an 80% sized backup to your production, there will always be varied other sources. And perhaps you just choose to load shed in truly black swan scenarios, rather than paying for enough backup for every possible rare scenario. Life does go on.

Though I confess predicting it is beyond me and I’m not sure how you would model it to achieve conclusions generally applicable to every country / market .

Reply on news.ycombinator.com