The South Australian black out — A grid on the edge. There were warnings that renewables made it vulnerable

Australians are going to be talking about this for weeks. Indeed, the SA Blackout is the stuff of legend.

The Greens are blaming coal (what else?) for causing bad storms and blackouts. Forget that Queensland gets hit with cyclones all the time and the whole state grid doesn’t break. Some greenies are also raging against “the politicization” of the storms. Yes, Indeedy. Go tell that to Will Steffen.

We are not being told the whole story. We do know that South Australia has the highest emphasis on renewables in the world. It also has a fragile electricity network, and wild price spikes to boot. (Coincidence?) The death of a few transmission towers should not knock out a whole state, nor should it take so long to recover from. The storm struck worst north of Adelaide near Port Augusta but the juicy interconnector from Victoria runs in from the south, and goes right up past Adelaide and most of the population. Why couldn’t the broken parts of the system be isolated?

Digging around I find ominous warnings that while the lightning and winds probably caused the blackout, the state of the South Australian grid appeared to be teetering on the brink, without enough reserve, or without well planned protection mechanisms to cope with an inherently unstable system. The excess of wind power made the system more fragile, and also made it harder to restore. There appear to be three reasons (at least) that excessive wind power is less fun, more costly, and golly, but if windmills don’t stop storms, why buy those expensive electrons?

1. Wind power adds instability of the system – not only does it ramp up and down frequently on an hourly scale, but it’s harder to mesh at the cycles per second scale too. This is about maintaining the “frequency” of the system (in Australia’s case thats 50Hz). Windpower is a type of energy that doesn’t easily synchronize with the 50Hz frequency (or any stable frequency). Other generators that have turbines that spin at regular speeds do (coal, gas, biomass, and hydro). They are easy to synchronize.

The frequency thing is critical — think of AC — Alternating Current — as being a push-pull of electrons 50 times a second. If any source of electricity joins the grid out of phase or at any other frequency, like say 49*, the waves of electrons are going to get out of synch fairly quickly. And we’d get horrible interference patterns of spikes and dips. This is a point where systems have to shut down (in seconds) to protect everything. This is an intrinsic design vulnerability in a system which prioritizes renewables over “thermal” energy.

*UPDATE: Thanks to Tomomason and Analytik and some great comments below, I now know that the frequency varies a little as load and supply ebb from 49.85 – 50.15 (See also the subthread by co2isnotevil at #5). These tiny variations are used as feedback for plant operators to adjust their operation. Read both subthreads for more information. This is why the whole grid is so much more stable with a dominant supply from synchronous turbines (ie thermal, biomass or hydro).

2. Wind power can’t be used to reboot the system and SA was getting warnings about that too.

Commenter Andrew W at WattClarity:

“ the ElectraNet boss on radio this morning mentioned that wind generated electricity cannot be used for ‘black start’ processes, that they need to get full control of load and frequency before introducing wind..“

To do a Black Start (cranking up the whole grid from nothing) we need hydro, or thermal, but wind power is not much use. InDaily reports that not only is wind not much use, but that SA electricity wasn’t prepared with extra fuel at the gas generators. (It’s amazing they got things running again at all really!)

[InDaily] A report on South Australia’s electricity system, published by AEMO last month, warned that there was a limited capacity to reboot the state’s electricity system in the event of a total blackout.

“There is a limited pool of strategically-located SRAS (system restart ancillary services) in South Australia to meet the current standard,” the report says.

“This indicates reliance on a single fuel source for all generation involved in the system restoration process in South Australia.

“Many of these gas-powered generating units do not have dedicated fuel storage facilities, exposing South Australia to further risk if there was a gas supply interruption during system restoration.”

3. Wind Turbines shut suddenly at high speeds. There is a possibility that a sudden shut down can happen when turbines are going full tilt in storm force winds hit “danger limits”:



This is speculative – There are suggestions that a lot of wind turbines were powered up at “high-wind, storm-velocity” levels and were generating high wattages when they reached their shut down limits and suddenly switched off. That would cause a major drop in the system. This type of failure would belong in the “census” night silly management category. Surely it could not be so? Surely, also, this could be overcome if wind turbines were shut in a staged sequence when known high wind incidents were coming. I want more data.

StopTheseThings explains both the first and third problems: Another Statewide Blackout: South Australia’s Wind Power Disaster Continues. The post on WattClarity supports the first one with a lot of detail. No hint of the third though. Both sites were very useful. The commenters too.

What wind-turbines poorly produce,

Is unstable, unsound and diffuse,

As they can’t meet demand,

Or high winds withstand,

They’re pointless, defunct and no use.

–Ruairi

An Unstable System

StopThese Things tells us that they hear that SA grid managers are running the system at 220V, not 230V (like the rest of Australia) in order to cope with the fluxes from wind power. It would be good to get confirmation of that. In November 2015 after a large blackout in South Australia, StopTheseThings predicted that after the coal plant was shut in April 2016, there would be statewide blackouts:

It’s also to be borne in mind that these 110,000 homes and businesses were plunged into darkness at a time when SA’s Northern and Playford coal-fired plants at Port Augusta (with a combined capacity of 784 MW) were still happily chugging away.

The owner of Port Augusta’s plants, Alinta has already signalled that it will close them in April 2016, due to the market distortions caused by the massive subsidies to wind power set up under the Large-Scale RET. If it does, South Australians can expect statewide blackouts with the kind of regularity that you’d be hard pressed to find outside of sub-Saharan Africa.

There was an August warning from AEMO that SA can’t cope with “contingencies”:

An ominous hint here on August 10th from the AEMO, reported on a dedicated electricity blog WattClarity. At the time SA faced a different threat (a planned outage in a Victorian supply). The AEMO was warning that SA doesn’t have enough local supplies to cope with any interruption:

“Another day where LOR2 notice issued for SA – what does it mean?”

[Paul McArdle August 10th] In shorthand, this means that if something happens (like the critical imports from Victoria tripping – a low probability event, but still a credible one, and so one AEMO needs to plan for) then South Australia would not have enough local supplies that could be dispatched in time to keep the SA system stable, so portion of SA load would be turned off (i.e. some lights would go out) to keep the broader system in South Australia online.

To sum up my understanding of some of the factors:

1) Plenty of wind in South Australia currently, making it uneconomic to run much thermal plant currently (especially with today’s gas price still $7.89/GJ at the Adelaide hub); 2) This is especially the case as the Heywood link constrained to flow west currently (i.e. South Australia can’t export its “economically surplus” wind), driving prices in South Australia lower; 3) Not much thermal plant running, so not as much capability to ramp up production in South Australia if needed, hence the LOR2 notice.

Paul McArdle goes on to point out (or quote someone, it’s not clear) that the AEMO arranged to pay some providers to carry spare capacity in case of a contingency:

My layman’s explanation of “Raise Regulation” FCAS is that it has to do with some generators agreeing with AEMO (in return for some small compensation) to keep a bit of “spare” capacity in reserve (i.e. not have it dispatched in the energy market), ready to give the system a (very quick) extra kick should the system suddenly slow below 3000rpm. This (frequency drop) would be what would happen in South Australia at these points in time shown if:

(a) the interconnector was to trip or

(b) some generator (wind, or gas) in SA was to trip.

Looks like we got (a) and (b).

So South Australia was already running a riskier system, with warnings that an incident could push the system over.

From WattClarity – a video on the complex South Australian situation unfolding on Wednesday.

This ten minute vid is for serious electricity-grid nerds. First it explains parts of the dashboard then they roll forward in 5 minute blocks through the day (you get a real sense of just how dynamic the grid is. What a headache to manage!) Helpfully the silent video has a few notes as it goes, but the central theme for me was how normal it appeared until it fell over in the space of five minutes. The lightning struck at 4:18, the “blackout” official notice was issued at 4:21, so this dashboard in the video shows normal at 4:20 and “black” by 4:25 (at 8:40 mins). The AEMO reported that 1900Mw was shed, and all supply and load in SA was lost. The interstate interconnectors are shown at “zero” by 4:30. It’s all over. Lights are off everywhere. People lie on dark operating tables, trains stop, lifts jam. Nearly 2 million people stop what they are doing.



_________________________________

Does the sudden shut down of high speed wind turbines add to the problem?

The StopTheseThings Another Statewide Blackout: South Australia’s Wind Power Disaster Continues.

STT lays the blame on the shifting surges in wind generation and the rapid shutdown of wind turbines. I’m not convinced, but it’s an interesting thesis that I’d like more information on. One of the things about wind power is that they have automatic shut offs at high wind speeds. Potentially they can be generating high levels of energy when suddenly they cut off — and that could destabilize the system. Did this happen (if it didn’t, could it?) STT has a lot of discussion, in the post and after it and on connected posts. I’d like to see a detailed graph of what happened from 4pm – 4:30, minute by minute.

Commenter Jackie Rovensky says

“We were all aware of the weather conditions being forecast, but no one in the energy or wind industry thought to start shutting the turbines down or off in a controlled gradual process to prevent a catastrophic effect of a sudden loss of energy in the system. Combined with this was apparently the Gas plant being hit by lightening. Why did the wind industry NOT take precautions, why did they just keep operating as hard as they could – was it because they were in competition with each other wanting to make as much money as they could during this period. How much damage was done to the Gas plant or was there any damage? No one has been asked that question by the media and our insipid Premier of course would not offer such information even if he new it.”

A few points about this graph. It does show a spectacular fall off. The time is WA time (I assume because I downloaded it). The AEMO said that lightning struck at 4:18 AEST. You can play with this graph on the Aneroid Site, including seeing individual wind farms and their production. There is not enough detail in the graph though on the scale of “the five minutes that matter”. The jaggies leading up to the crash are impressive but there are jaggies on other days I searched randomly like Sept 26, and Sept 24.

Thanks to commenters here for their helpful suggestions and links. Jaymez, your working theory was right.

Last word goes to TdeF September 29, 2016 at 2:03 am

The government is responsible for energy security, not the power companies or the electricity market or Victoria or someone else. This demolition job done on South Australia’s previously reliable and adequate power supplies should see the resignation of the Premier who has presided over this devastating nonsense at huge expense. Is this why South Australia gets twice the GST of WA? A desalination plant no one ever needed? Total blackouts? No gain whatsoever for the people of South Australia in this Green energy and windmill nonsense. How are the people of South Australia better off in any way? It is an utter disgrace. Hot summers and stormy days come and go but destroying a state’s infrastructure for a political agenda is an utter disgrace and a betrayal of the very purpose of a government. Wetherill should accept his responsibility for this utter mess and resign.

Freaky weather month: While there are storms on the East Coast, In the next 24 hours Perth may register its coldest September on record (or things might be a tiny bit warmer than in September 1906. Did coal burning cause that cold spell?) Thanks to Chris Gillham for tracking this exciting race so closely. More on that tomorrow.

BACKGROUND to the SA Electricity crisis (all the links).

People saw The South Australian black out coming. There were warnings that the dominance of renewables made it vulnerable. Then when it came, it all fell over in a few seconds — read the gruesome details of how fast a grid collapses: Three towers, six windfarms and 12 seconds to disaster. Ultimately the 40% renewable SA grid is crippled by complexity. The AEMO Report blames renewables: The SA Blackout was due to lack of “synchronous inertia”. The early estimates suggest the blackout costs South Australia at least $367m, plus their normal electricity is twice the price, and there are reserve shortfalls coming in January 2018 (pray for a cool summer). Welcome to the future of unreliable electricity: Rolling blackouts ordered in SA in 40C heat. And more bad luck for South Australia, yet another blackout, 300 powerlines down, 125,000 homes cut off. See all the posts on Renewable Energy and Electricity Grids.

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