> Solar is great, wind is great, Hydro is great - what happens when these don't work? What will you use?
The chances of a simultaneous and extensive wind, solar, and hydro outage on a national grid scale is... fairly low.
The chances of a simultaneous and extensive wind, solar, and hydro outage on a national grid scale is... fairly low.
Solar drops to zero every night.
For hydro, there's already seasonal variation with rain/snow melt. Beyond that, it looks like the majority of hydro in the US is on the west coast, which has been experiencing a drought for years and is projected to get worse. The west coast is big on removing dams for habitat restoration, too.
Wind: Admittedly I have no idea what sort of consistency wind has. But it does seem reasonable to assume the overall reliability of wind power will decrease as installed capacity increases, assuming we started with the most productive geographies first and then move to increasingly marginal areas.
In the same way that storm fronts travel through an area and bring high speed winds perhaps there is the opposite, where relatively sudden, large-scale lulls form?
To minimize the likelihood of blackouts we'd need to either:
1) Build sufficient excess capacity of wind/solar/hydro to overcome variance in output. This may not be feasible, if even possible, considering the points above.
2) Maintain fossil fuel peaker plants.
3) More nuclear for base load.
Having written these thoughts out I now realize your statement presumes we can ever (and always) meet 100% of electricity demand with wind/solar/hydro in the first place.
Yes.
There's enough countries out there that have been using renewables consistently for years (esp. EU countries). I don't understand how this is still a talking point. Daily variance in supply is equalized by trading energy with your neighbors which uses the phenomenon described above: The sun is always shining somewhere.
For Germany in particular it was a mistake to move away from nuclear before coal (imo lobbying is mostly at fault here) but they've been building renewables since the late nineties. It took them the time it takes to build a single nuclear reactor to move to more than 50% renewables and those are much easier (= cheaper) to maintain for the years to come.
And there are great savings by packing batteries behind the inverters along with the DC panels. Inverters can be a shared cost between the panels and batteries. Already, falling panel prices make the inverters an be increasing cost. Second, because panels are so cheap relative to the full install cost, most installations already have undersized inverters compared to maximum solar output. This lets all that "wasted" energy get stored and delivered later when it has much more value and a higher grid price.
Honestly, in the year 2023, batteries are a much more capable and scalable and realistic grid asset than a nuclear reactor.
Solar definitely does drop to zero every night and no, we don't have the connectivity, or the land-mass, to have sunshine somewhere all the time. Russia does...but well, Russia.
There is not "literally always wind". And we've had several days of "Dunkelflaute" in Germany per year now, much higher than anyone predicted.
Renewable advocates like to average over time, so having too much energy at some point in time (which makes the energy worthless and prices go negative, as in "please stop feeding energy into the grid, it's harmful!!") and having too little at other times averages out. As my statistics professor used to joke: if your left leg is standing in liquid nitrogen and your right leg in boiling fat, you are enjoying a nearly perfect mean temperature. Variance matters.
And so the real world does not work the way renewable advocates would like, and no, we don't have nearly the storage to make that work, nor a credible way to create such storage at remotely affordable prices, never mind the horrific environmental impact of that much battery production.
> There's enough countries out there that have been using renewables consistently for years
Nope. One example that is frequently cited is Denmark, but they themselves say that this is only possible because they are a tiny country with lots of neighbours with reliable electricity supply from whom they can purchase when they need it. They also have more interconnect with those neighbouring countries than typical total demand. This is not a model for other countries, particularly not for larger countries.
> The sun is always shining somewhere.
This is simply not true.
> For Germany in particular it was a mistake to move away from nuclear
Absolutely. Probably the biggest political mistake of the after-war period.
If you don't believe that we can meet our needs with wind/solar/hydro/batteries, then you haven't bothered to study the problem at all.
There's soooo much literature out there on how to do this.
And even without 100%, getting to 90% wind/solar is super cheap and deployable today, and by the time we spend the 15+ years deploying that, we will have tons of new tech to deal with the remains few percent.
Even France never got to 100% nuclear carbon free power, why not do the cheap thing to get to better than France levels of low carbon energy?
If you have any literature to recommend, I'm happy to read it.
As I write it right now Denmark is producing 0 solar, and only 12.5% of its wind production. Because its cloudy and there's little wind.
So they have to import almost 40% of electricity from Norway and Sweden where electricity generation is propped up by nuclear
When I wrote this it was even worse in Germany. 30% of total electricity coming from coal. Because:
- The total installed capacity of wind covers Germany's needs. Only 28% of installed capacity is produced
- The total installed capacity of solar exceeds Germany's needs. Only 2.7% of installed capacity is produced
That is, currently Germany needs 65 GW of electricity. Solar + wind have a total installed capacity of 134 GW, double what Germany needs. And together they still barely produce 30% of what Germany requires.
So Germany supplements that by burning coal, biomass and gas, and importing electricity.
The lesson learned is not “green power bad”, it’s “don’t rely on gas from dictators”.
Ah yes. This war is the reason why 134 GW of renewable energy only produce ~20GW, and why Germany burns 20 GW of coal (by pure coincidence that's about as much as the capacity of all decommissioned reactors since 2011)
https://www.reuters.com/markets/commodities/energy-crisis-fu...
The long term plan was always EU-wide energy projects to account for “its cloudy in Germany” scenarios. That plan isn’t complete.
Again:
- is it war that makes renewables produce 15% of their installed capacity?
- is it war that made Germany shut down 20GW of nuclear power plants?
> That plan isn’t complete.
And it never will be complete. Because when it's cloudy in Germany, those clouds don't stop at Germany's borders. Literally see the comment above about Denmark.
No form of power meets its theoretical "installed capacity". No one runs their nuclear, gas, coal, or oil plants at 100% 24/7/365 either. Yes, some days it's less windy; some days it's more cloudy. The dramatic fall in cost for new solar and wind capacity makes the solution pretty obvious; you build more to account.
> is it war that made Germany shut down 20GW of nuclear power plants?
It's war that makes Germany temporarily wish they hadn't.
> Because when it's cloudy in Germany, those clouds don't stop at Germany's borders.
They're unlikely to cover the entire EU's interconnected grid (and there's talk of generation in Morocco; https://www.washingtonpost.com/climate-solutions/2023/04/13/...). When the entire EU is covered in clouds, it's especially unlikely that there's no wind at the same time.
Given Germany's plan is 60% renewable generation by 2050, not 100%, they clearly understand the need for some flexible options for the tail ends of things.
And yet unlike renewables nuclear (and coal and gas etc.) are very close to that. And nuclear routinely runs close to its capacity, predictably.
> When the entire EU is covered in clouds, it's especially unlikely that there's no wind at the same time.
So each EU country has to overprovision enough solar and wind to potentially generate power for the rest of the EU countries? Case in point: https://news.ycombinator.com/item?id=38276778
Sure. Apples to oranges; they're not the same thing. Theoretical perfect-day max generation isn't how you provision solar/wind, that'd be stupid; the folks building out Germany's renewable efforts aren't stupid.
If you need a certain baseline of a certain renewable, you overprovision (and trade capacity with other areas and generation methods). Given the cost of new solar/wind capacity these days, that still makes perfect economic sense. Any long-term renewables plan is going to include energy storage and peaker plants of some kind to ensure a reliable grid on a national/continental scale.
How much? Is 200% of required generation enough? Is 500%?
Germany - and the rest of their interconnected EU grid - will continue to build out cheap, clean power for the forseeable future.
Indeed. And what's your point?
> By building more renewable sources, we will need less and less fossil capacity.
How many more renewables?
The installed capacity of renewables in Germany is double its needs for power.
The installed capacity of renewables in Denmark is 1.5 times its needs for power.
Do we need 10 times more? 100 times more?
As mentioned elsewhere in this thread, the peak production makes German electricity cheap enough to make everyone around them use it when it's available. If all the neighbors used this approach too, over the course of a day it would be everybody's turn to provide energy for the neighbors as renewables production will never be zero globally.
I'm not.
What I'm pointing out is that renewables in Germany are significantly overprovisioned. And still produce just 15% of their installed capacity because it's a quiet cloudy day.
> the peak production makes German electricity cheap enough to make everyone around them use it when it's available.
Ah yes. When they are available. That's the point, isn't it?
> If all the neighbors used this approach
Denmark is at 150% of its needs, was importing 40% of its energy from neighbors, and, ironically, from Germany which was burning coal.
So. How much each of the neighbors, and each of those neighbors' neighbors etc. need to overprovision renewables?
And we get it, Germany burn coal for electricity. And we all know that is bad. Point taken and not objected.
To be clear, Norway has no nuclear. 99% of generation there is hydro. Low wind in Denmark likely means they release more water for a bit; system works as intended.
See my addendum comment about Germany for example. They had to burn coal to keep up with the demand while their 200% overprovisioned renewables could only generate 20% of required electricity.
Today the only countries were renewables worked at close to 50% installed capacity were UK (wind) and Greece (solar). Everywhere else at best wind and solar were at 30% production. The entire Europe was busy burning gas, coal, or hoping that neighbours have enough nuclear and hydro installed.
> Norway has no nuclear. 99% of generation there is hydro.
Yes, this was my mistake. I should've said: propped up by stable energy sources: nuclear (Sweden) and hydro (Norway and Sweden)
Which is up from pretty close to 0% just a few decades ago (example: https://en.wikipedia.org/wiki/Wind_power_in_Germany#/media/F...). We're just getting started; this is a multi-generational megaproject.
You seem to think people are declaring the shift to renewables to be finished. I'm not sure where you obtained that misunderstanding.
Germany already overprovisioned. 200% of electricity requirements. And yet...
When I point out that even overprovisioning doesn't seem to work, people deflect, deny, stop responding, or reply in non-sequiturs.
So. Given that yesterday renewables in only two countries (Greece) managed to reach 50% of their installed capacity (not all renewables, but different types of renewables), how many renewables need to built to make sure that all of EU needs are met?
You keep saying this, and then you keep saying they don't have enough. These both cannot be true, and Germany's continuing to expand their wind/solar efforts indicate they don't believe they've "overprovisioned" yet.
Germany's plan goes out to the 2050s. Your complaint that they haven't provisioned enough yet is not in good faith.
They are not.