> It's not that easy, and the 2025 blackout good evidence of that. Renewables need a grid that's engineered for them and that require significative investments.

The outage in spain had multiple complex causes.

While the grid had a rather routine instability/oscillation on-going during time of the incident, the actual point-of-no-return was completely non-technical: Prices crossed into the negatives, which caused generation to drop by hundreds of megawatts and load to increase likewise within a minute (!) because the price acted as a non-technical synchronized drop-off signal for the grid.

In grids where the price action is not forwarded directly to the generators and consumers there would be no incentive to suddenly drop off decentralized generation. So for example in Germany a black-out would not happen like this.

You can download the full ENTSO-E report here: https://www.entsoe.eu/publications/blackout/28-april-2025-ib... (See page 10 for a broad incident timeline)

Unfortunately, to have an informed opinion, you pretty much have to read all these pages, because the situation is just so complex. Otherwise, you just fall for agenda pushing from all sides.

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phatfish 4 days ago | parent | next [-]

Yup, its interesting that a community supposedly of "engineers" are happy to claim expert knowledge of domains in which they have no experience.

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yayachiken 4 days ago | parent [-]

That being said, I was apparently also under the impression of outdated or just plain wrong information.

While the report I listed mentions the sudden loss of decentralized generation as starting point of the blackout, and also specifically mentions small-scale rooftop PV, it says that the cause for that sudden synchronized drop-off is actually unknown.

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robocat 3 days ago | parent [-]

You can't get an "informed opinion" by reading crap like that report.

The Spanish systems have systematic design failures for stability and electricity market design. Working out the political failures that led to the design failures is much harder.

Consultancies like https://www.nera.com/capabilities/power--utilities--and-rene... specialize in advising about electricity networks and market design.

Only those working closely in that profession have any knowledge of the underlying causes.

Most everyone else (including this comment) is different levels of ignorance and cluelessness.

Edit E.g. Crap quote from the report "but no significant oscillations with amplitudes above 20 mHz". The rest of it is about that level from what I could tell.

	▲	yayachiken 2 days ago \| parent [-]
		> crap like that report > Only those working closely in that profession have any knowledge of the underlying causes. This report is literally from the ENTSO-E which is the main regulatory body for the grid in Europe. > Crap quote from the report "but no significant oscillations with amplitudes above 20 mHz". What is the "crap" about that? An amplitude can still be measured in Hz, if you are looking at oscillating frequency deviations, if that is what you mean.

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samuel 3 days ago | parent | prev [-]

Very timely, the final report has been released today.

I hadn't read the document you referenced, and I admit don't have the prior knowledge, nor the time, to fully understand all the implications of what it says. My opinion is then the result of reading and listening a variety of experts and news sources, and it will have some biases, for sure.

Still, I have skimmed the final report to see if there was something that I could understand from first hand (and to support my original point, not gonna lie), and I found this:

_The increasing penetration of variable renewable and distributed generation, further market integration, broader electrification, and evolving environmental and geopolitical risks place the European electricity system under increasingly challenging operational conditions, requiring higher levels of resilience._

Do you really think that my original point (as uniformed as it might be), namely, that the levels renewable energy currently present in the spanish grid require significative investments, was wrong?

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yayachiken 2 days ago | parent | next [-]

Yes, I think it's wrong, or at least way over-exaggerated.

You can run a grid to supply approximately 80% renewables (long-term average) without significant technical changes.

Only if you want to get the last 20% to renewables, you get technical challenges, e.g. related to synchronization and load-matching. But that is also not unsolvable problems, e.g. instead of relying on the inertia of steam turbines you can "just" build specific-purpose fly-wheels to do the same thing. It's just less elegant.

Source: Volker Quaschning "Understanding Renewable Energy Systems", too lazy right now to look up the exact page.

This is also consistent with the section they quoted. Generally, the load matching in grids is done by the system itself. If you add more wind and solar, which depends on the weather and location, you have to more large-scale intervention, e.g. allow generation re-dispatch. But that doesn't immediately imply that this is a dangerous process.

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adrian_b 3 days ago | parent | prev [-]

I have not read the report yet, but in another thread someone gave a very plausible explanation of what happened.

The high levels of renewable energy happened to contribute to this incident, but not because of something inherent in renewable energy. All renewable energy sources are connected to the grid through inverters, and in Spain most of these inverters do not use an adequate control policy, i.e. they do not compensate the phase fluctuations of the grid, like the synchronous electromechanical generators do (i.e. they do not generate an appropriate amount of reactive power for compensation).

Technically it is easy to implement such control policies in all solid-state inverters, but it was not done in Spain because there were no incentives, i.e. there were no regulations specifying how the inverters connected to the grid should behave, otherwise than disconnecting when the frequency went outside a permissible range.

	▲	yayachiken 2 days ago \| parent [-]
		Yes, that is plausible indeed, but the problem is that there are many explanations which are plausible, but there doesn't seem to be a smoking gun. Strange about that explanation for example is that the time correlation is backwards. First the solar generation started to drop out and only then central generator stations tripped. Also the on-going frequency oscillations had already stabilized. If it was related to frequency issues, the solar inverters would either have shut down 15 minutes earlier (while the frequency oscillations were at the peak) OR 1-2 minutes later (when power stations tripped and frequency would have dipped)