As moderators we can only guess why people flag things, but there are other reasons why people may have flagged that comment, the foremost being that it broke the guidelines due to its inflammatory style.
On Hacker News we want to be able to discuss difficult topics involving arguments people may find counter to their assumptions, but you need to express things in a way that's persuasive rather than combative.
I don't see that.
> and factually incorrect.
Then substantiate your point.
Stability is one of the things grid operators pay for-- not just production.
Your other comment probably got flagged because it started with a huge straw man and had multiple unwarranted jabs in it.
Also, have you read after the market part? Please watch this video https://www.youtube.com/watch?v=7G4ipM2qjfw if the last quote is gibberish to you. It discusses somewhat different issues, but the point still stands.
Why is the problem the cheap source of supply rather than the market rules and incentives that made everything act the way it did?
Your comment suggests move back to good ol' expensive fossil generation instead of looking at how to bring the market rules up to date with evolving technologies.
I explicitly mentioned this line of argument in the GP. The problem is that renewables only sometimes cheap and plentiful and often not when we want it. Even without accounting for the politically-driven preferential treatment covered in the sibling comment, from the purely technical point of view intermittency above certain threshold wreaks havoc in the traditional grid architecture designed for the traditional easily controlled "rotating" generation. It becomes really hard to manage the grid with existing tools when you have too much of intermittent highly distributed generation and in the extreme it leads to collapses like this.
As I wrote, yes, you could upgrade the grid, increase transmission redundancy, add battery/pumped/flywheel storage, introduce "smart" tools to manage the grid, and do a plethora of other things to accommodate renewables. Hell, you could even migrate the grid to DC!
But the cost of doing it is substantial. It's effectively a form of externalities of renewable generation, which are not accounted for in naive "cheap" $/kW metrics. Properly accounting for those externalities and adding them to the cost of renewable generation is possible, but politically unappealing.
>Your comment suggests move back to good ol' expensive fossil generation instead of looking at how to bring the market rules up to date with evolving technologies.
No, I believe we should remove the politically motivated shoehorning of renewables at the cost of grid stability. There should be a limit on how much intermittent generation we can have depending on the preparedness of the grid and we should pay less for power from such sources, not guarantee purchase from them!
As you say, we should have proper incentives structure which accounts for various externalities (including CO2 emissions!). We need to remove the existing subsudies on renewables which made sense in the early days, but not now. Let the generation sources play at the even field.
> Properly accounting for those externalities and adding them to the cost of renewable generation is possible, but politically unappealing.
Implying this was/is not done and should be done. As a certified fan of looking out for (cost) dependencies, I agree with this to put it very mildly. I find it unlikely this wasn't done however, rather, I think renewables were likely onboarded harder than the externalities were taken care of to allow for it, possibly due to political pressure and/or mismanagement. Or at least, that rings all too familiar to me personally, not just from real world topics, but even from work. But then what you actually propose is:
> There should be a limit on how much intermittent generation we can have depending on the preparedness of the grid and we should pay less for power from such sources, not guarantee purchase from them!
Which is a different concern.
Also, this reads to me awfully like just flowery language for "hey, what if the obviously bad thing that happened wouldn't be allowed to happen anymore" with the logic retconned into it, but then I'll never have a way of proving or demonstrating that conclusively.
Finally,
> We need to remove the existing subsidies on renewables which made sense in the early days, but not now. Let the generation sources play at the even field.
This further doesn't follow from even your own explanation (i.e. "which made sense in the early days but not now" is not a substantiated claim). It's just your own political stance on the matter to the best I can tell.
Market-based economies are great to follow technology trajectories and are efficient at capital allocation but even for them we need additional incentive structures to speed up the process.
I also think that most countries have massively reduced subsidies for new projects but existing subsidies will still be served for a long time.
Something like: the first 10Gw after start and the last 10GW before a stop make 50% of the revenue than the rest. That should disincentivize suddenly turning everything on or off depending on energy prices.
I'm glad people are coming around to accepting that renewable energy has problems. We have some solutions to these problems but we do not have experience with them.
I agree entirely - the externalities of renewable energy are significant and are not paid for by the source of the problem - the renewable generators themselves.
Just as one example, what is the solution to an extended wind drought, say of a week or ten days? All the batteries in the world could not store enough energy for that.
A major challenge with renewable energy is that it is intermittent and variable but also unpredictable. it is impossible to predict wind speeds more than 24 or 36 hours out and even those predictions are often inaccurate. just building more wind turbines or solar panels won't cut it.
There is also the reluctance of grid operators to use the capacity available in renewable energy generators. The majority of wind turbines are capable of active and reactive power control but most grid operators either don't use this capacity or use it minimally.
A distribution connected wind turbine could do wonders for reactive power control but this is rarely done. More grid operators should pay for reactive power, like the UK is starting to do. This should also be sourced from EVs and small solar inverters.
Looks like there are a multitude of schemes of various vintages in Spain, which tl;dr basically give you a guaranteed price per MWh you generate. So imagine you get a 100eur/MWh subsidy for a (legacy) solar plant. The market price is €-20/MWh. You will still continue to produce power until the price reaches -100MW/h. Even worse are some contracts for difference (poorly thought through) which give you a guaranteed price regardless of what the market is at. So even if the price was -1,000eur/MWh the government or grid operator would still give you your €50/MWh (and the subsidy would be 1,050/MWh!).
The problem is if you reform this (and it is happening worldwide) solar is much, much less appealing. Because suddenly your solar plant which was getting (say) a guaranteed 70/MWh all year round suddenly does not make money for 6 months of the year at least at peak sun hours.
On top of all this, you have a lot of domestic solar in places like Spain. The grid operator _cannot_ control these assets in nearly all circumstances. They will continue to dump power into the grid regardless of the market price. This again will change but it requires an awful lot of work to retrofit invertors with remote control capability OR a lot of public backlash for charging end customers who bought solar in "good faith" now getting hit with peak time negative prices (so they change their behaviour).
I think my core message would be _any_ negative power prices is a sign of market failure. Acceptable in rare extreme occurrences, but the fact most of europe has highly negative prices very frequently is telling you the grid and market design is not able to handle what is going on.
This massively simplifies reality.
E.g. in Finland where I live we also have issues with negative power prices. A few years ago we had some really low prices. It turns out, a fair bit of wind power producers never opted to add to their windmills any remote shutdown possibility, nor did they have the ability to monitor prices and react to them automatically. I.e. they just kept generating no matter the price, and had offers in at the network level at the lowest permissable price.
Since then, when they lost a non-insignifcant amount of money by running at negative prices, they've started installing control electronics in windmills and building IT systems and prediction algorithms to be able to react to this.
In the EU it is not as simple as "turning off when the prices are negative" since producers offer a certain capacity to the grid in an auction system the day before. You have to predict the weather + overall demand and set your offer accordingly.
No, that is not what the report says. It says, just like you say, that renewables reacted to market prices, causing a generation drop. It then says explicitly that synchronous generation caused oscillation, while PV plants showed a flat non-oscillating pattern.
From your comments I worry there are emotional factors clouding how you're reading the report - this was a systemic failure involving many separate technologies:
- Market signals - negative prices - caused a drop in PV generation (as frequently occurs)
- Synchronous plants caused oscillations as a side effect
- Plants procured to dampen exactly those oscillations did not deliver as requested
- TSO then took measures using interconnections to stabilize via other balance area
- This caused - presumed - overvoltages in distribution grids
- PV inverters then shut off, as mandatory by regulatory requirement in response to over voltage
You're absolutely right that PV played a large role here, but that point is diminished by making it out that PV is both the source of the initial generation drop and the source of the oscillations; it is neither.
The market design caused the generation drop, synchronous generators caused the oscillations, TSO action caused distribution overvoltages and regulatory requirements on PV firmware design in response to overvoltage caused the final blackout.
But that takes time and requires some rebalancing, because much of that capacity is not closest to the producers. It also requires water, which becomes scarcer in the autumn (not the case here).
So the price can and does become negative for a window. “High frequency trading” the spot prices probably contributed to the problem.
In the case of Cruachan Power Station: “It takes just two minutes for a turbine to run up from rest to generate mode,” says Martin McGhie, Operations and Maintenance Manager at the power station. “It takes slightly longer for the turbines to run down from generate to rest, but whatever function the turbines are performing, they can reach it within a matter of minutes.”
https://www.drax.com/power-generation/in-energy-storage-timi...
The reality is that electricity is complex and that renewable energy presents a new set of problems, problems to which we do not yet have complete solutions.
There is not much fast trading to be done on a nuke/gas/coal/hydro powerplant ramping up or down, but there is a lot of instability (and thus market volatility) to be found in fast varying solar/wind conditions.
Renewables just change one set of challenges for another set, at the end of the day it's all manageable.
Don't forget rotational inertia. This gives the system a high-frequency response mode: it can resist sudden demand changes through stored kinetic energy, effectively acting as a low-pass filter with a fast dominant pole.
As you get a smaller share of generation with rotational inertia, you need a lot more buffering on short to medium timescales.
And, of course, it doesn't help for longer timescales that in many places renewable production slopes off in the late afternoon right when demand slopes upwards for cooling.
Demand rises because that's how people have their system set up. That cooling load can be shifted earlier in the day by using a slightly smarter thermostat to precook your house when the electricity is plentiful.
You can do this a bit, but the insides of houses don't have that much thermal mass and the best insulated houses add a pretty large phase delay that makes the quickest rise in internal temperatures during the late afternoon as framing in the attic heats up.
I don't have a lot of luck in accomplishing meaningful precooling in my house. My best plan is to suffer until the late afternoon, turning on the AC at the end of the peak demand period when at least outside temperatures are lower, my AC units are shaded, and the cooling is more efficient.
The incident was NOT caused by a lack of system inertia. Rather, it was triggered by a voltage issue and the cascading disconnection of renewable generation plants, as previously indicated. Higher inertia would have only resulted in a slightly slower frequency decline. However, due to the massive generation loss caused by voltage instability, the system would still have been unrecoverable.
(Spinning mass on its own doesn't do much to deal with the voltage fluctuations. It's entirely something that's reactive to grid frequency, which is the most 'global' indicator of supply vs demand in a grid, since it can't fluctuate locally. But voltage and current can vary wildly in different parts of the grid, and required separate management)
– the concrete causes of this specific blackout; – how the existing grid is not prepared to deal with the current energy mix; – the energy policy of the past decades, from the nuclear moratorium in the 80s to the large subsidies for renewable generation of the past couple decades.
A person's strong opinion on any one of these issues will inevitably influence their opinion on the others.