Induced atmospheric oscillations.

Aircon possibly is, but everything else shuts down by and large. Or used to. I dont remember much aircon at all from my time there.

New one to me. I think RR have a better chance, but who knows? Bring it on!

I don't see why. Naively, I would expect that solid state components should be able to deliver a very quick response, at least equivalent to the natural/analogue response of a back force in an alternator/fly wheel.

My human nature guess would be no one has bothered to try.

Well the probabilities are not known, or are not appropriate. Kathryn Porter mentions they do not even measure grid inertia. However, people knew the grid was resilient to fluctuations in supply and demand. So when someone calculates the risk of a solar farm going offline, they did it in the context of a historically resilient grid with inertia. The known probabilities they used were wrong, the significant probability in the context of a renewable dominated grid, with much lower inertia, was unknown.

Not at all, it just pushes back against a bias of people who live in a world tailored to just work.

That example is inappropriate. The principle is about providing proof, it is not a proof in itself.

In software programming terms, it would be about having a suite of unit tests. Traditionally, the way we developed was to make a code change, and then test it in the local context we were interested in. It fixed the problem we were interested in, job done! However, we got bitten by unintended consequences that we weren't clever enough to spot. So as a precaution, we run the whole suite of unit tests.

Perhaps the precautionary principle is poorly specified. But there is a human tendency to ignore that our environment is tailored to be safe. You see it in political terms, when it is just compensating for a natural human bias.

Exactly, I didn't know what some of the terms meant.

With many papers, you can only understand them by reverse engineering from a full understanding of the implications. But,..If you already fully understand the issues, there is no point in reading the paper.

You may have noticed that Kathryn also didn't understand all the concepts, but being a decent fellow, I wouldn't point that out, as it wasn't core to her description.

Well they have. That's what those battery banks do. My guess is that synthetic inertia is a bit tricky.

I think that's a bit muddled really. The reality is more like no one bothered about grid inertia because there was always more than enough

That is not how the term is used by the Climate Change alarmists.

Wiki The precautionary principle (or precautionary approach) is a broad epistemological, philosophical and legal approach to innovations with potential for causing harm when *extensive scientific knowledge on the matter is lacking*. It emphasizes caution, pausing and review before leaping into new innovations that may prove disastrous. Critics argue that it is vague, self-cancelling, unscientific and an obstacle to progress"

The only one I couldnt get to grips with was I think BUP or somesuch

Well that's not exactly true. What I liked about it was that it managed to come up with a neat metric for characterising the inertial energy on the grid compared to the power the grid was delivering, and that has the dimension of time.

So 9 seconds of energy good, 3 seconds not

I am not sure that is correct.

Something occurred to me.

In the old days we had tons and tons and TONS of spinning mass in the generators. This gave short term frequency stability in the grid - if the frequency shifted a little bit all those tons had to speed up or slow down to match, and as they did so they stopped it changing very fast. Even if the grid waveform wasn't a sine wave they'd be correcting automatically.

We don't have as much spinning mass any more. As Spain has gone to almost all "renewables" they've got *** all.

If you put me into a project designing the software to control an inverter to change DC output from a solar farm or a windfarm into AC for the grid I'd be monitoring the grid frequency so that I knew when I ought to be putting power into the grid. This varies at 50Hz, and doubtless has all sorts of higher frequency stuff laid on top which must be ignored.

Suppose I got it slightly wrong, and my reaction to grid frequency variations was a little bit slow. I put out my 50Hz power wave, monitor the outgoing current, and if it isn't quite lined up with the sine wave I expect I tweak the commands I send to the inverter.

But having got it slightly wrong there's a lag. Which means that when the frequency drops I only start trying to push it back a few seconds later. And similarly when it rises.

And suppose that software like this is running in all the inverters in the entire grid.

The frequency drops a little. All the inverters notice, and push it back faster. Not quite at once, but a couple of seconds later.

Which means that the frequency rises. Perhaps a little higher than 50Hz.

All the inverters notice this, and push it back slower. After a few seconds. And it overshoots again. And again. And again... A classic positive feedback loop.

In the end a couple of them give up and turn off. Then some more.

And suddenly Spain is in darkness.

Andy

Well that is of course a problem in complex system theory and feedback, which is not unkown to electrical and electronic engineers.

I think the point is that first of all you haven't appreciated how the generator would respond to having its phases advanced, It would be like shorting its output. The issue is less frequency control than the unavailability of energy in spinning masses to enable that control, Hence the use of batteries.

Frequency insatiability is not the problem - it's a symptom, and the cure is to fix the problem - not the symptom.

The problem is no stored energy on the renewable grid.

And the price of putting it there now exceeds the cost of having a nuclear power station in the first place, that wouldn't need it. Hence renewable energy is essentially worthless.

So:

make then react faster?

add some energy storage (small capacity but high instantaneous current) so that they can work both ways, very short term adding or subtracting, just as the rotating mass does? Needs a bi-directional inverter, but they seem to be a thing already.

nib

Yep. The key is that the inverters are no good without the storage

Which is just another reason why wind and solar are a crock of s*it

Orsted pulls out of huge wind farm due to high costs:

Quote:

Orsted said the project no longer made economic sense, despite signing a

Just over half of the country's power currently comes from wind, solar, nuclear and biomass – organic matter. The government wants to raise that to

In order to meet that target the UK will need to triple offshore wind capacity and double the amount of solar and onshore wind power on the system, according to estimates by Aurora Energy.

It will also need a significant upgrade to the electricity grid with 620 miles of new power lines as well as substations and other equipment. Unquote

Don't worry, HMG will just find a way of increasing electricity prices even more to slip another lucrative long-term bung to Orsted.

Good luck with that, then.

Toujouurs les ecobolleaux...

A summary of grid inertia that I found useful:

nib

It seems deliberately obfuscating and hand wavey to me.

Seemed okish to me.

It made clear, to me, that in the new world, inverters should not just follow grid frequency but should be responsible for establishing and maintaining grid voltage and frequency. i.e. they should dictate frequency.

The problem in the old world was that turbines could only increase mechanical power slowly, what they called primary frequency response (PFR). This is effectively how fast they can generate extra power from extra gas, akin to how fast a car engine responds to stepping on the accelerator. With traditional turbine generators, this is a 0.3%-2% increase per second. So, using these figures, it might take a generator

However, inverters can have a much faster response, going from 0 to 100% in 0.5 seconds.

So we don't need inverters to have inertia, we just need them to have spare headroom to generate extra power and for them to dictate grid frequency rather than just follow it. Batteries can produce sudden bursts of extra power, when needed.

This whole thing isn't about any great technological difficulty, it is just about politicians/grid controllers cost-cutting, delaying making the changes they know are needed. i.e. It is due to politics not science.

Not a conclusion that will surprise many here.

ChatGPT did it for me, Torque Mechanical and Torque electrical.

It's just Newton; Force = mass x acceleration etc, in a rotational context. I'm not an engineer, I'm not familiar with these symbols.

I spent a lot of my career working out what people actually did, in order to develop software to automate it. I was ignorant of their business, ignorant of their terms. I wasted a lot of time unravelling the jargon they used to express the most simple concepts. More often than not, they invented some mystique that they were doing something complicated. Often they didn't actually understand what they were doing, they just understood the jargon bullshit.

So now, I'm a little intolerant when I see people not explain things.

More 1/2 mV^2 actually, Energy. Not momentum

To someone who doesn't understand, complexity looks and sounds like bullshit

How can they when they have no reserve of energy to inject into the grid?

This is not synchronisation problem It is an ENERGY problem.

So waht?

Finally he gets it! But where is this extra power going to come from?

All masters and no slaves. Fighting each other. Yes, batteries can, but they are expensive addons to an already fiendishly over budget technology

You cant have many inverters dictating frequency. The Grid is one synchronised thing and everybody has to synch to it. No one generator sets the pace. What happens is that as frequency drop more power is fed into to fossil and hydro turbines to restore it. Because they run off stored energy. But they are not themselves master clocks. The guts running the grid are simply doing their job adding more power up to the max when demand calls for it and easing back if the grid overspeeds.

Renewables can't do that.

Battery packs can BUT the peak power demands are very high which makes for a very expensive set of batteries.

In this case it is exactly about technology and about cost. As well as politics and profit

The point at which renewables + long transmission lines + batteries + occasional gas become *more expensive* than even massively inflated nuclear power is already here.

Its political only in the sense that the EU has mandated renewables, not carbon reduction. And no rules have been set by OFGEN or equivalent to make renewable generators pay for long transmission lines + batteries + occasional gas backup, because if they did they would absolutely not be cost competitive.

In short its possible to stabilise the grid, with long transmission lines + batteries + occasional gas backup but that doesn't meet the EU imposed Renewable Obligation. It still has gas.

And who pays for the long transmission lines + batteries + occasional gas backup? Not the renewable operators. They are only expected to deliver power. Not reliability or stability.

So it falls to the grid operator to either build that themselves or contract it out *and pass the costs on to the consumer*.

Indeed.

The second equation is energy. My point was the equations served no purpose. They were pretentious. If you already understood the symbols, you almost certainly knew the equations anyway. It is pseudo-science. Besides, we all know net torque spins up or slows down wheels and flywheels have energy.

No, I was perpetually ignorant, but I had to develop systems that worked. No one cared if I pretended to be clever, they only cared if the programs I wrote produced the right results. To produce working systems I had to understand, I couldn't accept bullshit, or gloss over stuff.

Expert, Industry practitioners only had to convince their colleagues that they understood stuff, office politics.

Obviously, some systems are complex, but a lot of it wasn't. The trick was to find the easy stuff that could be automated.

Yes they are cost addons, politicians aren't willing to face up to the costs of grid support. That is a political issue, not tech.

But..., every turbine generator is a master. That is what the frequency drop is all about. They spin the turbines up to an appropriate speed, dictating the grid AC frequency. Put a load on an alternator and Te (torque electrical) increases, becomes greater than Tm (torque mechanical) to produce a net torque slowing the turbine.

This was quite confusing to me, because the articles all described frequency drop as a primary grid characteristic, when it is just an artefact of increasing current in turbine alternators.

Well, you're not doing peak power, you're just smoothing sudden changes. You're only doing it for a couple of minutes.

Really speaking, a smart grid could also pull extra tricks. Like reducing load, large refrigeration plants etc turning off. It doesn't need to all be batteries. There is no problem occasionally turning off fridges for a couple of minutes. It is clearly the way things are going.

Not really. With SMR, offshore wind, Gen IV reactors there is an aspect of tech aspiration, (or wishful thinking). Batteries and grid sync is simpler, more understood, just economics and engineering.