Australian renewable energy transition. Part 3

From Climate Etc.

by Chris Morris and Planning Engineer (Russ Schussler)

Technically, what are wind and solar doing to South Australia’s grid?  And why is South Australia’s electricity so expensive?

Part 1  covered renewables impacts so far on the major power system in Australia. Part 2  covered how the renewables hype doesn’t match the reality.

This post provides details about the extra services and functions a grid provides and how the grid in Australia is being impacted by the increasing penetration of wind and solar generation.  And how this makes Australia’s electric power so expensive.

Reactive Power

Alternating Current (AC) power generation aims to produce an alternating voltage in the shape of sine wave, whereby the current has a similar wave at the same frequency. However, the current may not be timed in phase with the voltage. AC power can have three types of load, depending on how it affects the timing of the current to the voltage: resistive, inductive & capacitive. For a purely resistive load, the current and voltage are co-incident. However, this is not the normal case. Electric loads and grids have both inductive and capacitive elements. Inductive elements want to maintain constant current flows, while capacitive ones want to store charge (voltage). Active power is measured in Watts. With AC  being a cycle, there is another value orthogonal to it, called reactive power, measured in units of Volt Amps Reactance or VARs.  The diagram below explains the relationship.

Generators and inverters produce some mixture of “real” and “reactive” power. That is why them and transformers are rated in MVA, not MW like their prime movers are.  Real power, in watts, is the form of electricity that powers equipment and does work. Reactive power, in VARs, is the energy supplied to create or be stored in electric or magnetic fields in and around electrical equipment. VARs are 90° out of phase with real power. Reactive power (inductance) is particularly important for equipment that relies on magnetic fields for the production of induced electric currents (e.g., motors, transformers, pumps, and air conditioning.) Negative reactive power (capacitance) seeks to slow voltage waves by acting as a store for charges. The balance between real and reactive power is adjusted to meet the needed load and grid requirements.

Transmission line elements both consume and produce reactive power. Under conditions of light loads,  transmission lines are net producers, and at heavy loads, they are heavy consumers. Reactive power consumption by these loads tends to depress transmission voltage, while production of transmission voltage (by generators, transformers or synchronous condensers (syncons) or injection (from storage devices such as capacitors) tends to support voltage. Due to the characteristics of components on  the grid , reactive power can be transmitted only over relatively short distances during heavy load conditions. If reactive power cannot be supplied promptly and in sufficient quantity,  voltages decay, and in extreme cases a “voltage collapse” may result. If there is too much capacitance, voltages rise to excessive levels, damaging the insulation of equipment.

Worldwide, motors comprise about half the load on the grid. Air conditioning loads are almost exclusively motors. As well as needing the active power, motors produce significant reactive power. The distribution Network elements (local “low voltage (<66kV)” lines, transformers and switchyard components) have to absorb this reactive power, usually by increasing the voltage at the transformers. If the system can’t compensate for the reactive power or has no more capacity, then the voltage starts to drop, while the motors’ current and reactive power increases. This compounds the overvoltage problem – why you get brownout in the suburbs on those muggy hot afternoons.

Because of the lines and transformers in a grid, the VARs at each part, or even at either end of a single transmission line, can be significantly different. That means compromises or corrections need to be made throughout the distribution & transmission network. This is done by modifying generation output settings, changing transformer tap point settings and switching in or out capacitors, inductors and synchronous condensers installed at strategic locations. Grid operators monitor the various parameters, then adjust the settings as the generation source and loads change.

All this explanation and discussion about reactive power may seem esoteric and irrelevant. It isn’t. The large 2003 blackout in the USA/ Canada was caused because they weren’t managing reactive power properly because they had an inadequate system understanding.

Modern renewables are often sited a long way from where the load will be consumed, requiring long spur transmission lines. Consider the grid map showing current and proposed generators of New South Wales as an example – the load centres are on the east coast and the wind & solar generation a long way west. There will need to be long and uprated transmission lines to take the power east. The loading on those lines will be unpredictably variable. There will be times when they carry minimal current as well as times when they are at or near full rating.  This variability requires the switchyards along the line to have expensive equipment to manage the VARs and stabilise the voltage. This extra switchyard equipment will be needed when there is little generation to provide the VARs. All of this additional switchyard compensation adds substantially to the cost.

There are problems with having transmission from generator to load by separate routes – effectively paths in parallel from an electricity flow viewpoint. There are also problems with running transmission routes in parallel. Because the impedance (resistance in an AC circuit) can vary significantly between the lines, circulating currents can occur that increase the line loading. The magnetic field lines around a transmission line can also induce currents in adjacent conductors when there are two circuits on the same towers.   There are also additional risks associated with parallel circuits. When a low rating line constrains the capacity of a bigger line, the small line will reach its rating long before the other line approaches its rated capacity. This condition is called the spring washer effect. It can be corrected by using compensation devices in the switchyard, but this increases the cost and complexity of the system.

Frequency Control & Inertia

The frequency is the timing between wave cycles in an AC system 60Hz (a Hertz is one cycle per second) and 50Hz in most of the rest of the world. The frequency has to be the same across the whole grid – it is one of the things that defines it.  A stable grid frequency is critical for effective  operation. Thermal plants usually provide this by using governor control, whereby the frequency drives the plant output through a negative feedback device. The grid system operators may also run real time or short period dispatch, whereby the plant operators increase or decrease load over short time periods on grid operator’s instructions.

The inertia, provided by the rotating machinery of the generator, serves to slows the rate of change of frequency (RoCoF) . The slower the frequency changes occur, the less stress for the plant on governors. And as there is linkage, a small RoCoF in “normal” grid fluctuations will also stabilise the voltage and reactive power requirements.

However in recent times, there have been significant and rapid swings in the Australian grid frequency between the control limits, shown in the graph below. The gray region is the deadband of allowable frequencies where no intervening measures need be taken by the grid operators. When outside the deadband region, generators are supposed to be offering primary frequency response support – for underfrequency (load is greater than generation), grid operators increase the generators’  output. This is either done automatically or by dispatching plant to increase load.  From the rate of frequency decline, calculations indicate there could have been at least 600MW shortfall in generation over the five minute dispatch process. The cause of the variability observed hasn’t been positively identified, but is likely to be uncontrolled solar generation. If that is the case, then it indicates that faster acting and more expensive frequency control services are needed.

Inertia on a renewables grid can be provided by synchronous condensers or by large battery banks with specialised electronics. Of course, the batteries have to have enough charge in them to function, so they are reserved for just that purpose and thus can’t be used for other purposes like general market dispatch.  However, AEMO does not appear to believe that renewables and batteries are a substitute for the frequency response provided by synchronous units. To quote the latest available report:

“To comply with the requirements of IPFRR, Semi-Scheduled generators will typically need control of active power that allow for simultaneous MW curtailment, MW ramping, frequency response outside a relatively small frequency deadband, and ongoing variation in input energy. While such MW control capabilities do often exist in isolation, when they are tested simultaneously, and in an ongoing manner, software problems have often been found. This then requires further development, updates and testing to address, a process that has in some cases proven significantly more time consuming than initially expected.”

To manage the frequency balancing, the grid operates short period dispatches, mainly raising and lowering generation over short time periods: 5 minute, 60 seconds and 6 seconds are the main time periods. The time reflects how quickly the grid operator can respond to be up to the dispatch level. Because of frequency control problems that are occurring,  Australia grid operators now proposing putting in place  a 1 second response time dispatch.  They go out to the market for bids from suppliers of these resources.  This process is referred to as Frequency Control Ancillary Services (FCAS). Provision of FCAS is expensive for the NEM. In the first quarter of 2020, FCAS cost was about $110M, but this has dropped back to about $40M a quarter. In 2010, before there was significant wind or solar on the grid, the FCAS cost was about $2M a quarter. FCAS costs are operational charges to be paid by consumers for the privilege of the renewables penetration.

As an aside, for those that want more understanding of renewables and market grid operation, the commentary at WattClarity is worth following. They explain events well and use their showcased analysis software to provide detail and insight.


Resolving frequency control and inertia concerns does not resolve the imbalance between load and generation. This is where generation reserves come in. Reserves are plant capacity that is not actually generating, but is available to power into the grid within a short time period. By rebalancing the generation/ load, the frequency departures are resolved.

The reserves needed are usually sized to cover the loss of the largest supply item on the grid. This can be a circuit on a transmission line or the biggest single generation supply point. For South Australia, this is generally the rating of the Heywood interconnector when it is importing power into the state. Reserves can consist of large grid-following battery banks with sufficient charge in them to run for quarter of an hour or more. To reduce the risk of single point failure, the reserves should come from a variety of sources. Some of them may be units that are partially loaded and can ramp up their generation; others may be hydropower units acting as synchronous condensers, or they may be batteries.

To illustrate the problems with lack of reserves, South Australia power generation has been having major problems recently: the –9th , 16th and 23rd February in particular. On these days, the wind diminished early in the day, but the lost generation was covered by the grid solar and domestic solar. There were also gas turbines running to provide the inertia. As the afternoon went on and solar dropped, they needed to load first the gas turbines, then start the diesel engines. This is shown in the graph from Wattclarity below. Note this is only South Australian generation; it does not show flow across the interconnectors which at the last time interval was 677MW. Batteries provided very little power. It appears that despite batteries supposed to be there providing generation when there is a lull in renewables’ generation, it is there unused but providing FCAS reserves. This is probably because it gives the owners more income. But this is counter to why the batteries were supposed to have been installed. What is providing the backup generation, other than thermal plant which renewables and batteries are supposed to replace?

Part 1 and Part 2 gave examples of this duck curve problem  . The Heywood link was running at capacity, but the grid declared a reserve shortage as there was not enough market bids to supply extra generation to cover the system need in the event of a potential trip of the interstate connector. Graphics at Box 6 provide a description of the system during this event. All this meant the price went very high, punishing the market buyers. And for those that claim negawatts and interruptible power is the answer, Part A6 on the 23rd event shows there was only 1MW available. As the Wattclarity author described it, “decidedly underwhelming”.

The same general process would occur for over-frequency situation, but for this circumstance generation would be shed or batteries switched to charge. That is a process a lot easier to manage.

Load Shedding

Grid operation is more than just keeping the load and generating balanced and providing a stable frequency. Grid capabilities must be able to cover its fundamental operating parameters like frequency, voltage and reactive power when things go wrong.  Examples would be when a lightning strike occurs, or a transmission line failure or a generation plant trip. The grid needs both inertia and fast acting reserves as backup. Protection systems take time to sense and then react to changes in frequency. Circuit breakers typically take 3-10 cycles to fully disconnect once they receive the trip signal, but these are only the last steps in the chain.  The protective electronic sensors have to sense that the frequency or line impedence is outside its allowable range, and then activate the switching relays and the switches take time to break the circuit. The gap between allowable and load shedding is a fraction of a Hertz. To give time for the protection and reserves to function, the frequency (and voltage) have to decay as slowly as possible, which is where the (RoCoF) becomes important. There is a relationship between RoCoF, inertia and load lost as a fraction of total load, but even a change of 1 Hertz decline a second is considered risky.

That is why when major events happen, inertia to slow the RoCoF is so critical. South Australia went black in 2016 because a lot of wind generators tripped off, the major interconnector got overloaded and tripped, then there was not enough inertia, and the frequency collapsed so fast that system load shedding schemes couldn’t operate and everything protectively shut down.

Because of the blackout, AEMC now takes the problem of low inertia very seriously. They instituted rules setting inertia requirements for each state, particularly South Australia. AEMO used the rules to set minimum inertia levels.  This means that gas turbines are required to be on, while wind or solar is taken off the grid, which overrides the merit order bid stack.  South Australia is now replacing some of the inertia previously supplied by gas turbines with synchronous condensers and grid forming battery banks, using reserved sections of the giant batteries. This has added further to the cost of operation.

AEMC has been struggling with the problems of frequency management in a renewables dominated grid. They are looking at tight requirements for frequency management, RoCoF and related issues. AEMO will then use those to set rules for compliance by each state’s grid . Whatever the final rules and requirements are determined to be, they will increase costs to the power user, both in capital and operating costs.

Automated load shedding is usually managed at the distribution network level. These schemes normally work on under-frequency  trigger setpoints. This is achieved by tripping complete feeder circuits from substations. There will be target load reductions (typically 10 to 20%) and these typically occur in two separate stages.

As might be expected, problems are occurring in South Australia associated with the automatic under-frequency trip levels When there is significant uncontrolled domestic solar on the grid, then there is very little grid-supplied load. This means that the underfrequency load shedding will have little effect stopping frequency decline. AEMO have put limits on the Heywood interconnector well under the cables’ rating in certain conditions to counter this risk. The SA Network company is also looking for solutions to these concerns.  There are major potential problems during the daily duck curve rampings. The grid can’t protect itself if a significant event occurs while the power is having to be rapidly increased. AEMO has recognised this risk but there are no measures put in place yet. Previous experience suggests that it will likely take another major outage event before a solution is found.

System functions during frequency excursions

The graph below of an idealised frequency excursion caused by a generation trip shows how it all fits together. The section labelled ‘dynamic response’ is normal frequency control behaviour. After the incident, the slope of the RoCoF is a function of size of load loss and the inertia. The higher the inertia, the shallower the RoCoF slope. When the frequency is dropping, the generation frequency control and fast acting reserves put extra power into the grid. The frequency nadir means the input is enough to stabilise things. The higher the RoCoF, the lower the nadir.

After the nadir, frequency slowly recovers as the slower acting reserves come in. Often, there is no steady state section, but there is enough excess generation from the reserves and existing generation picking up load to bring the frequency back to the normal value.

The above graph shows the “ideal” grid behaviour to a loss of generation. In reality, the behaviour can be more like the graph below, which plots the number of the Queensland coal stations tripping in a cascade. Here the frequency got so low that under frequency load shedding occurred.

As part of the Queensland failure, the voltage there dropped so the reactive power went up, which tripped switchyard compensation. The current inrush flows in the interconnector got so high that it tripped, islanding Queensland for 15 seconds until things were stable and balanced enough to reconnect automatically.

Queensland was “saved” by the high grid inertia. If it had of been renewables powering the grid, and a similar cascading failure had occurred, it is likely that it would have been a collapse to blackness.


The above is a simplified explanation of what is needed for reliable grid operation. Proponents of renewable energy do not want to discuss concerns of this sort, particularly the costs involved. When forced to address these issues, they rely on magical thinking, advocating for technologies that either do not yet exist or have not yet been proven to work reliably on a grid. The known solutions are expensive, but the renewable sector doesn’t want to pay for them – their mantra remains that renewables are cheaper than fossil fuels so the others should pay for them – hiding the expense. Add in the costs from the needed system support requirements described above, then renewables are significantly more expensive (and less reliable) than conventional generation. The extra costs of renewables support are being paid for a deteriorating quality of electricity supply. That is why there is a new industry adage –

Cheap renewables are very expensive.

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March 17, 2023 2:05 pm

I thought that the black system event in South Australia was very instructive and am shocked that nobody has leaned anything since then.

Nick Stokes
Reply to  Hivemind
March 17, 2023 4:28 pm

Just not true. According to this article:

“Because of the blackout, AEMC now takes the problem of low inertia very seriously. They instituted rules setting inertia requirements for each state, particularly South Australia. AEMO used the rules to set minimum inertia levels. This means that gas turbines are required to be on, while wind or solar is taken off the grid, which overrides the merit order bid stack. South Australia is now replacing some of the inertia previously supplied by gas turbines with synchronous condensers and grid forming battery banks, using reserved sections of the giant batteries. This has added further to the cost of operation.”

Forrest Gardener
Reply to  Nick Stokes
March 17, 2023 9:44 pm

What, Nick, have you learned?

Reply to  Hivemind
March 18, 2023 12:47 am

It’s all under control-

This trial is a crucial step in understanding how we can take that next step
“Making dumb solar smart:” Push to bring old rooftop PV into new world of flexible exports | RenewEconomy
the rooftop solar fan club watching early adopter FIT rates shrinking to zero are naturally enthusiastic about taking said next step/s with changing the weather-
“Sun tax” gets closer, but not much clearer, as networks outline solar export tariff plans | RenewEconomy

Alan Watt, Climate Denialist Level 7
March 17, 2023 2:22 pm

Cheap renewables are very expensive.

Kind of like “free love”.

March 17, 2023 2:25 pm

The above is a simplified explanation of what is needed for reliable grid operation. Proponents of renewable energy do not want to discuss concerns of this sort, particularly the costs involved. When forced to address these issues, they rely on magical thinking, advocating for technologies that either do not yet exist or have not yet been proven to work reliably on a grid. The known solutions are expensive, but the renewable sector doesn’t want to pay for them – their mantra remains that renewables are cheaper than fossil fuels so the others should pay for them – hiding the expense. Add in the costs from the needed system support requirements described above, then renewables are significantly more expensive (and less reliable) than conventional generation. The extra costs of renewables support are being paid for a deteriorating quality of electricity supply. That is why there is a new industry adage –
Cheap renewables are very expensive.

this isnt a problem. its an opportunity!!!

currently working on my third demand response project.

get paid to use electricity in large amounts in a 5 scond windowget paid to shut your plant down in a 5 second window.
provide frequency stability to operators by supplying a variable load of industrial size.

It doesnot add up
Reply to  Steven Mosher
March 17, 2023 3:50 pm

So who gets to pay for your systems? Who pays to test that they work in the context of a large grid with other devices also attempting to correct perceived problems, rather than amplifying the problems through destabilising interactions with other components? How much damage do they do to production processes, which has to be added to the costs? Why is your system better than synchronous condensers, batteries, STATCOMs etc.?

Peta of Newark
Reply to  It doesnot add up
March 17, 2023 5:40 pm

Because he’s using the power to create fake money for himself (Bitcoin mining)

Or, as some naive & gullible folks inside the BBC imagine, for powering ‘data centres’

Headline:Tiny data centre used to heat public swimming pool
Just how much grunt is that thing burning?
There is not a single thing ‘right’ about what’s going on inside this thing – unless you regard ‘The Love Of Money‘ as ‘right’

It was exactly that which created the oversupply problem from domestic rooftop solar = the greed which said that the inverters in those systems **had** to constantly run at the Max Power Point of the solar panels.
By doing that. they will push unwanted power into the grid while the sun’s shining and so cause frequency and voltage to rise.
(in an AC grid, the two are intimate)

No. Those domestic rooftops should have been told to be a bit more sensitive to grid frequency than they are – that they should have their own accurate internal clock or given access to a ‘frequency standard’ ##
i.e. That they be ‘grid connected’ and not ‘grid tied’

## Such as the Rugby or Droitwich MSF clocks or even good old BBC Radio 4 as was.
The carrier for BBC Radio 4 long-wave at 198kHz was in fact (maybe still is) an absolutely rock solid gold standard clock.
When it said 198kHz, it meant 198.0000kHz all the time and by being = long-wave, travelled most the way round the globe

The grid-tied/connected inverters’ programming could then have sensed rising frequency and thus backed off their output.
And similarly, that would leave them with some ‘reserve sunshine’ that they could call upon to hold up the grid if they saw the frequency falling.
But no. They *had* to be programmed to run flat out all the time – basically to recover the costs of their installation.

Again we see that the human animal cannot lie. By setting up the inverters as they did (max power all the time) they are telling that solar is not cheap = if it’s not run flat out all the time it wont pay for itself
Yet endlessly we are told something else. Often ‘by omission’ or should that be; by O’Moshion

edit for fans of Feedback
By having the domestic inverters = grid tied, they were using the grid as their clock.
Because on an AC grid, voltage and fequency are intimately connected, to remain tied at all times those inverters had to (automtically) increase their voltage if the frequency started rising – pushing ever more power into the grid.
But a rising frequency should have been telling the inverters quite the opposite.

yes? Do you see a positive feedback system?

And Positive Feedback systems *always* self-destruct.

The domestic grid-tied inverters should have been programmed to do negative feedback and this wouldn’t have been an issue.
Sadly, The World would have to endure a dearth of Bitcoins but, as we all know, there are no such things as Free Lunches

Last edited 14 days ago by Peta of Newark
Reply to  Steven Mosher
March 17, 2023 4:53 pm

Oh joy, yet another scammer seeking to get rich at other people’s expense.
First we create a problem, then we force people to pay us for a solution. What a gig.

Forrest Gardener
Reply to  Steven Mosher
March 17, 2023 9:45 pm

An opportunity for some to make money at the expense of others.

What ever happened to you?

Chris Morris
Reply to  Steven Mosher
March 17, 2023 11:04 pm

Steve as others have pointed out, you create a problem, then want to be paid to fix it. Nice work if you can get it. Anyway 5 seconds is too slow for Australia. With the narrow range between deadband and AUFLS, 5 seconds is about 4 seconds too slow for the RoCoF they are looking at in a low inertia grid. Probably it will be black before the negawatts come in.
Grid operators, from experience do not trust high speed load changes on inverter based systems. Really bad harmonics get injected. Look at what happened at Odessa. The systems are software based which has a high chance of unusual circumstances failures. No two trips are the same so simulations and software changes only cure the last problem.

Tom Halla
March 17, 2023 2:41 pm

Pointing out the issues of wind and solar on a grid besides intermittency. “It’s not that simple” is usually true.

March 17, 2023 3:19 pm

Good summary of a 3rd year Electrical Engineering degree, with a bit of Masters degree material included. The math behind all that includes calculus, differential equations, analytical trigonometry and linear algebra.

The policy makers couldn’t possibly understand the concepts shown in the triangles, much less the rest, as they imagine that electricity comes from the wall socket. The “man on the street” is too busy with TikTok and Instagram to even look.

Nick Stokes
March 17, 2023 4:01 pm

“Cheap renewables are very expensive.”

All those words and speculations and dark warnings, but nothing said to actually quantify it. When we come to
“Proponents of renewable energy do not want to discuss concerns of this sort, particularly the costs involved.”
there is very little actual quantification of costs. And of course, the flip side is that the grumblers never want to discuss the very concrete costs of buying gas and coal.

The only cost actually quantified was FCAS – frequency control, now often and best provided by batteries. The cost mentioned was $40M a quarter, so let’s say $160M a year. But the wholesale value of electricity generated in the NEM is about $28000M a year.

YallaYPoora Kid
Reply to  Nick Stokes
March 17, 2023 4:29 pm

Whenever new equipment not previously necessary is needed due to changes in grid configuration there is a flow-on cost to the consumer (unless subsidised like W & S by taxpayers).
Fossil fuel generation grid requirements were already paid for. Simple direct replacement of ageing FF generation rather than blowing them up aka South Australia would have been the cheapest solution requiring minimal infrastructure change.

How can you not understand this?

Reply to  YallaYPoora Kid
March 17, 2023 5:00 pm

His paycheck depends on his not understanding it.

Nick Stokes
Reply to  YallaYPoora Kid
March 17, 2023 5:19 pm

What is not paid for is the cost of the fuel used. And these costs are huge. Using UK numbers:
Wholesale gas: about £36 per MWh
Cost of gas to generate 1 MWh £36/0.6 = £60
Value of 1 MWh wholesale £113
Fuel cost is over half what is earned from final product. Wind and sun are free.

The SA stations blown up were being maintained by a coal mine in the desert, 260 km from Port Augusta, and a town of about 2000 people (in time of full production) with no other purpose. Water came from another dam in the desert 130 km away. A railway line to Port Augusta had to be maintained and staffed. Powerlines from Port Augusta to Adelaide, about 320 km, had to be built and maintained. These are real costs.

Reply to  Nick Stokes
March 17, 2023 6:20 pm

One constant with Nick, he never lets a good lie go to waste.

All of these claims have been refuted over and over again. He’s griff, with a bigger budget.

Nick Stokes
Reply to  MarkW
March 17, 2023 7:44 pm

Just heckling, with no content.

Forrest Gardener
Reply to  Nick Stokes
March 17, 2023 9:47 pm

Yes Nick. We know you heckle with no content.

Why is it so?

Nick Stokes
Reply to  Forrest Gardener
March 17, 2023 10:14 pm

Another mindless heckler.

It doesnot add up
Reply to  Nick Stokes
March 17, 2023 6:32 pm

Are wind turbines free? Does it cost nothing to connect them to the grid? Or to handle their intermittency? Does it incur no maintenance costs? Can wind be summoned on demand?

Fact is, wind cannot compete with low cost gas or coal on an even playing field. It needs an array of subsidies and perks.

Nick Stokes
Reply to  It doesnot add up
March 17, 2023 7:43 pm

Fact is, wind cannot compete with low cost gas or coal”
As I said, just no quantification. Just a list of alleged costs with no attempt to add them up.

But a way of quantifying intermittency did occur to me. UK has a capacity auction, currently bidding at about £60 per KW/year. 5.78 GW was preserved for 2023/4, at a cost of £347M. That is what generators are bidding to make capacity available to firm W&S. But again, pretty small beer (1%) when the wholesale value of elec generated is 300 TWh*£113*1e6=£34B.

It doesnot add up
Reply to  Nick Stokes
March 18, 2023 5:52 am

Here’s some quantified information. At the moment there are big warnings from the wind industry that the next round of CFD allocations are likely to fail to attract bids. The maximum permitted bid price for offshore anchored wind is £44/MWh, and £116/MWh for floating wind in 2012 money. That’s about £60/MWh and £160/MWh indexed to today. Those prices are unprofitable, even with no penalties for intermittency costs.

Nick Stokes
Reply to  It doesnot add up
March 18, 2023 3:08 pm

How is that a negative? It just means that they expect to sell the power at higher than the permitted strike price. So they spurn CfD (and so any chance of subsidy).

Reply to  Nick Stokes
March 18, 2023 6:04 pm

You want to quantify the cost of W&S Nick? Just legislate no tenderer of electrons to the communal grid can tender anymore than they can reasonably guarantee 24/7/365 (ie short of unforeseen mechanical breakdown) along with requisite FCAS or they can keep them for their own use/rs. It’s called a level playing field that users require rather than numpty headed State sponsored dumping that’s leading to inevitable Greenouts now.

Joseph Zorzin
Reply to  It doesnot add up
March 18, 2023 3:41 am

and of course environmental costs to wind and solar- on the landscape along with increased mining

Reply to  Nick Stokes
March 17, 2023 6:35 pm

If wind and sun are free ,wind and solar power would and should be cheap .
You have fallen for this scam Nick.
Invest in wind and solar and because you BELIEVE that there is no fuel to purchase you would refuse to accept any subsidies .
Any company producing electricity should guarantee power 24/7 .
Put your money where your mouth is Nick invest in wind and solar and also invest in backup power plants for when the sun doesn’t shine and the wind stops blowing.
I would expect South Australia has controlled load shedding to shut down water heaters and maybe electric car chargers when power generation slows .

Jim Gorman
Reply to  Nick Stokes
March 17, 2023 9:20 pm

You have no engineering training that equips you to have a clue about the complexities of building and operating an electrical grid. You don’t just wire this stuff into the grid by twisting some wires together with a wire nut.

Did you read about changing transformer taps? How about throwing switches to isolate section? How about rewiring whole segments to balance loads and transformers? How about the engineering required to monitor and set up the control decision points? It’s really all so simple isn’t it?

You would pee your pants trying to manually open switches on a high voltage line causing several feet of arc not that far away from your head.

Nick Stokes
Reply to  Jim Gorman
March 17, 2023 10:13 pm

Fortunately the world does not require me to do the wiring. But I can add up. And I can notice when people just dodge providing quantitative information.

Chris Morris
Reply to  Nick Stokes
March 17, 2023 11:22 pm

“People just dodge” – detailed in my comment up thread, you are very much the pot calling the kettle black.
And why talk about UK? The articles I wrote were on Oz grid.

Reply to  Nick Stokes
March 18, 2023 12:33 am

Hi Nick,
Can you please provide numbers in a link that show the national scale cost of Australian electricity that we used to have with coal, extrapolated to 2023, compared to the cost of electricity from windmills, operated say over a year, including the costs of backup during that year, (or with
W&S, your choice) nett of subsidies as conventionally defined? We can leave out, for now, extra costs like TNT for ageing coal plants, extra transmission lines etc.
It is rather hard to find such a comparison, for reasons I cannot understand. Accountants usually require such numbers prior to project approval, but they are adding up specialists also.
Geoff S

Reply to  Nick Stokes
March 18, 2023 4:13 am

Yes, you can do addition. Unfortunately, the article concerned requires (at least) calculus.

Nick Stokes
Reply to  Disputin
March 18, 2023 7:47 pm

I’m pretty good at calculus. Even complex analysis.

It doesnot add up
Reply to  Nick Stokes
March 18, 2023 5:58 am

Since you are unable to even assess the bill of materials you fail to provide quantified information. I have previously shown you that the East Anglia Green grid project implies six times more transmission capacity will be required to accommodate renewables. So let’s multiply grid costs by six.

Reply to  Nick Stokes
March 18, 2023 2:52 am

…wind and sun are free….

Once again this pointless mantra!

This proves nothing. The thing that matters is the cost of running a total system to current standards of reliability with them. And the risks of attempting it.

As Judith Curry recently said:

“Risks of a rapid energy transition to 100% renewable energy exceed any conceivable near-term risks from climate change itself.”

But the irresponsible intellectual activists who are trying to pressure our governments into attempting this, with little or no proper analysis of either costs or feasibility, do so safe in the knowledge that if it all goes pear-shaped they will none of them bear any accountability.

Dean S
Reply to  Nick Stokes
March 18, 2023 6:06 pm

And paid for in the cost of the coal.

Not everyone uses the same dodgy accounting as renewables advocates.

Reply to  Nick Stokes
March 17, 2023 4:59 pm

but nothing said to actually quantify it.

Nick Pick Nick is upset because the article didn’t give the exact cost of each of the items it talked about.

As to Nick’s assurances that his friend’s solutions really are best, he doesn’t attempt to explain why the article is wrong.
He just wants us to take his word for it.

Chris Morris
Reply to  Nick Stokes
March 17, 2023 11:18 pm

You put essentially the same comment on Judith’s blog. When I came back with ” How much is Snowy II with all the transmission lines going to cost each household Nick? What about the new AC line between SA and NSW?
Last time I looked, lignite in VIC was about $40/MWh.”
You didn’t address any of the three points but wanted to talk about black coal and gas.
However, The AER did quantify the costs of shutting down one coal plant.
Wholesale electricity prices higher since Hazelwood exit | Australian Energy Regulator (
Just one station really cost the householders. And it is likely there will be a similar effect when the bigger Liddell closes and they have to burn more gas to keep the lights on.

Chris Morris
Reply to  Chris Morris
March 17, 2023 11:29 pm

Liddell closing is already putting the costs up
Electricity market: NSW power grid squeeze raises worries on Liddell closure (
And modelling indicated it’s going to get worse
Concerns remain post-Liddell (
Note that is relying on Snowy 2 being available now

Nick Stokes
Reply to  Chris Morris
March 18, 2023 3:24 am

Here is a graph of wholesale prices following the closure of Hazelwood. There was a marked peak in Q1, 2019, in both Vic and SA. But it came down from the peak to lower levels, lower than pre-closure in 2020, and from then on prices were generally lower in the wind states (Vic, SA) than the coal states (NSW, Qld).

comment image

Nick Stokes
Reply to  Chris Morris
March 18, 2023 3:15 am

The main reason Hazlewood rather earlier than expected was a very bad fire in the mine that could not be put out for 45 days, and which had a very bad effect on quality of life in Morwell. It was near end of life anyway, but from that it never really recovered.

Closure of LIddell is an economic issue. It is becoming too expensive to run, and the owners want out. The only alternative is to invest massively in upgrading or building a new station. No-one is volunteering.

Reply to  Nick Stokes
March 18, 2023 3:41 am

Come off it.
You cannot equate a bit of smoke from a coal mine fire with the multi-million dollar annual electricity production. That is just laughable..
Who lit the fire, Nick? And some of the other fires that month? Do you have any contacts in the police force for inside information?
As I understand it, political constructs like mandated preferences for renewables, subsidies for same, caused Liddell to be operated in an uneconomical way. Combine that with various statements of hate for future coal and it is easy to see that we are in danger of losing a valuable resource through childish inputs from politicians and their aides. It should be evaluated on its unfettered performance. Geoff S

Nick Stokes
Reply to  sherro01
March 18, 2023 1:02 pm

“Who lit the fire, Nick?”
There were bushfires at the time, but it doesn’t matter. The point is that they couldn’t put it out, and for forty five days, both town and power station were disrupted. This was discouraging for the owners.

Reply to  Nick Stokes
March 18, 2023 3:44 am

 ”No-one is volunteering”

I wonder why that is Nick… Is it because renewables are subsidised to the hilt to the extent of making a new station uneconomic? Or, is it because the politics surrounding building a new station here would be just impossible? Or, is it because opening up new resources is becoming virtually impossible to fuel one?
Australia is blessed of being abundantly resource rich with the possibility of being one of the energy capitals on the globe, but politicians have fallen for the nut zero religion because of listening to alarmists like you.

March 17, 2023 4:02 pm

There is no “transition” to renewable energy, only “addition” of renewable energy.

Mike McMillan
March 17, 2023 4:14 pm

We need higher resolution charts. These are a bit fuzzy.

March 17, 2023 4:35 pm

My take on Australia’s network changes is that it might be theoretically possible to run a grid on solar, wind, hydro, whizz-bang new technologies that haven’t been invented yet, and a wing & a prayer, but not without a massive fleet of network support devices which would cost more and render the network less reliable than a moderate suite of nuclear reactors or SMRs which serendipitously have been rebranded “renewable” and which, like house/solar-car/battery symbiosis, will partner our new nuclear submarines.

March 17, 2023 9:22 pm

Wind and solar have too much baggage associated with them. We need to stop building them and disconnect the ones that are in operation now from the grid. The grid itself is more important than any benefit we might realize from wind and solar. If people want them for personal use fine but they must be stand alone and not screwing up the grid.

Nick Stokes
March 17, 2023 10:11 pm

“However, AEMO does not appear to believe that renewables and batteries are a substitute for the frequency response provided by synchronous units. To quote the latest available report:”

The quote given doesn’t say they can’t do it. It just says they need a software update. It goes on to say:
“For new Semi-Scheduled generation sites, some OEMs are now able to provide control system software that meets the requirements of the IPFRR, allowing for these new sites to implement compliant control system settings prior to or at completion of commissioning.”

A more recent report was blunt and explicit:

“AEMO has derived the following conclusions:

• Synchronous generation is not required for grid reference.

• The SA power system configuration (as of March 2022), including synchronous condensers (syncons), gridconnected inverter-based resources (IBR) such as wind farms, solar farms and battery energy storage systems (BESS), is capable of sustaining a grid reference in SA, even during conditions when no synchronous generation is online in SA. “

Chris Morris
Reply to  Nick Stokes
March 17, 2023 11:11 pm

The link you provided goes nowhere. However, you gave the date as March 2022. The report I gave links to was 17th November 2022.
March is not more recent than November, at least in my calendar.

Nick Stokes
Reply to  Chris Morris
March 18, 2023 2:52 am

Sorry about the link, it is here
The report was issued February 2023.

Chris Morris
Reply to  Nick Stokes
March 18, 2023 4:13 pm

Yes Nick, that is a more recent report. You do realise (if you have read Part 2), that syncons are synchronous units, don’t you. Note our wording.
With regards the report, note there were major limitations as they excluded significant scearios. Heywood regularly runs at 400MW, especially when Victorian coal allows virtue SA citizens to put their morning coffee on. What does the word solely exclude. They actually tell us
The report states “Based on this investigation, therefore, it may be concluded that synchronous generation is not needed solely for the purpose of grid reference in SA and that grid reference can be sustained in SA with the existing network configuration of syncons, IBR and BESS. This report does not consider whether synchronous generation may be required in SA for other power system security needs, such as adequate protection system operation, frequency control, and ramping reserve management, or for power quality purposes.”. So they can’t do away with synchronous generation for frequency control or ramping reserve management on the basis of this report. That seems to indicate my paraphrasing still is valid.
The last thing to note was that before 2016, both AEMO and Electranet saw no inertia issues in SA. Invariably grid operational rules, especially when changing the grid generation and load characteristics or technology is very reactive. Quite a few blackouts have occurred because something happened that they hadn’t thought was possible.

March 18, 2023 1:44 am

The cost of all this…

Nick continues to claim that if you install wind and solar the total savings from the fact that you do not pay for fuel, because wind and sun are free (when they are present) means that a system consisting of wind solar plus gas, with all the additional transmission and systems required, will be less expensive than a pure conventional system. Which would probably at this point be super critical coal.

He may be right. However, he has never given any quantitative study showing it, he’s never even done back of envelope calculations himself to show it. He has simply quoted the price of gas or coal and then contented himself with the flat assertion that this means he is right.

It doesn’t mean that at all. Its meaningless in itself.

The question is not about fuel. The question is about the total system costs of running a reliable electricity system for today’s society on one technology or another. You cannot settle this by just endlessly repeating ‘wind is free’.

What Nick is advocating is a huge change to the way in which a vital service is produced. Get this wrong and you are looking at social and economic disruption to the point of partial collapse. Our societies are based on reliable electricity at reasonable price. We need far more than the bare assertion from amateurs that its all going to be OK. We need a pilot project showing it working. And in advance of that we need a proper case.

Here is how you do this. Its done every day by product managers and investment appraisal committees in companies all round the world. Its called Net Present Value analysis.

You take all the cash flows – in this case it will be cash out only – by year. You will do this in the present case twice. Case A will have only coal or whatever conventional you are studying. Case B will have Nick’s favored configuration.

Sunk costs don’t count. So if you are doing South Australia as your example, the fact that you can use existing plant in one case but will need additional plant in the other requires you only to count the new plant as a cash out. You will also count the costs of maintenance and renewal of the existing, of course. You need to be very careful to include all costs, and both systems need to be delivering the same product or service. This is what goes wrong with LCOE – half of the costs are being left out.

Once you have cash out by year over the life of the systems, you then use the NPV function that comes with any spreadsheet package. The formula tells you, for a given interest rate, what each system costs when account is taken of the time value of money. You have to be careful when choosing the interest rate for reasons Brealey and Myers explain. A proper analysis would do several runs with different rates to explore the implications of the different timing of cash flows in the alternatives. You also need to take account of differing risks, as they explain.

There are lots of examples of this in Brealey and Myers, Corporate Finance. And indeed in any corporate finance textbook, this is just particularly clear and comprehensive and with lots of examples. Its not hard to do if you have the data.

If Nick wants to make the case that the overriding factor which will lead to better NPV for his favored system, is that wind and sun are free, this is what he has to do. Or, point to a study which has done it. Point to a pilot project and reports on it where its been done.

Otherwise, and until he does it, he’s an example of what Thomas Sowell has so acutely diagnosed as the constitutional disability of the current intellectual class. He is an intellectual who can be (and is being) as irresponsible as he likes and advise whatever he likes because he is not accountable for any of the consequences of having his advice implemented.

Nick is like an amateur at the start of the pandemic who cheerfully advises governments they need to undertake, or need not undertake, drastic measures of various sorts. While carrying no responsibility for the outcomes if his advice is followed. And without having done the work or produced studies which support his recommendations.

Nick Stokes
Reply to  michel
March 18, 2023 2:59 am

Nick is like an amateur at the start of the pandemic”

No, I am just pointing out the flaws in the posts of the grumblers here. I have actually given quite a few back-of-envelope calculations on this thread.

The problem that I keep coming back to is that the grumbles are unquantified. I’ve tried to do the best with them that I can, but it keeps coming back to this. There are very clear and easily quantified costs of fuel. A whole lot of objections are then raised, but whenever I am able to cost them, the costs are nowhere near that fuel cost.

Reply to  Nick Stokes
March 18, 2023 5:04 am

What needs showing is that a total system configured the way you want it, to deliver equal reliability and availability to conventional systems, is cheaper than a conventional system. As measured by Net Present Value analysis, that is, taking account of the time value of money and all cash flows through the life of the project.

All you ever do is to keep repeating that wind is free, which is irrelevant, or you dispute some detailed cost figures in posts, but you never engage with the cost of system point.

When you look at the total UK subsidies, which Paul Homewood has enumerated, your view seems very implausible. At the very least a lot more proof is needed before converting a national grid to it. But if you believe it, do the analysis (or point to one that has been done, or point to a pilot) and show it.

This is not about bits and pieces here and there. Its about total system costs, capital and operational. If you do not engage with total system costs you’re evading the important issue. And if you’re selling national grid conversion without doing or having the proper studies, you’re being totally irresponsible.

Nick Stokes
Reply to  michel
March 18, 2023 1:09 pm

And if you’re selling national grid conversion”
I’m not. I don’t get any money from it. I’m just disputing the many objections that are made here. If you want me to engage with total system costs, you’ll have to quantify them. All I see is a huge cost of fuel on one side, and on the other a whole lot of claimed bits and pieces, which on examination seem to be very small in comparison.

It doesnot add up
Reply to  Nick Stokes
March 18, 2023 1:27 pm

The “bits and pieces” (things like wind turbines, support towers, grid interface power electronics, etc.) that mean that wind is unprofitable at £60/MWh, without having to pay for grid and intermittency costs? Which is well above the cost of power from gas and coal generation delivered over most of the preceding decade.

Jim Gorman
Reply to  It doesnot add up
March 18, 2023 2:39 pm

I will almost guarantee that one of these days regulatory agencies will move to requiring power generating suppliers to put the costs of 99+% reliability in THEIR costs. It won’t matter how they guarantee it, but the politicians will tire of dealing with voters about the cost and reliability of electricity. That will let them point at someone else as the cause.

Nick Stokes
Reply to  It doesnot add up
March 18, 2023 3:19 pm

“(things like wind turbines, support towers, grid interface power electronics, etc.) “

That is why it is so hopeless trying to get an accounting of these bits and pieces claims to set against costs for FF. Those are capital items. You should set them against the capital costs for gas and coal. Whatever source is chosen, we need new power stations.

Jim Gorman
Reply to  Nick Stokes
March 18, 2023 4:41 pm


Have you ever ran a business. Capital is not free. There are interest expenses, depreciation expenses, opportunity costs. If they are necessary because of the elimination of fossil fuels plants, the wind and solar should be assessed the capital and associated costs. The fact that new fossil fuels plants may be needed because some were destroyed should also be assessed to wind and solar.

You are trying to minimize the new capital investments assigned to wind and solar. I assure you that will hasten the closure of all big fossil plants. Sooner or later wind and solar need will need to pick up the additional costs. Maybe not next year, maybe not in 5 years, but it will happen. When it does, those who participated in the farce will never be listened to again. Some may even have fraud leveled against them.

Reply to  Nick Stokes
March 18, 2023 4:18 pm

Looking for examples of you disputing dreams of a hydrogen economy, dreams of a vast solar array with a cable to Singapore, dreams that Australia must resist nuclear electricity, etc etc.
You get credibility when you do not wear a big extreme green heart on your sleeve. Geoff S

Nick Stokes
Reply to  sherro01
March 18, 2023 5:50 pm

a big extreme green heart on your sleeve”
That’s from St Patrick’s Day.

Jim Gorman
Reply to  Nick Stokes
March 18, 2023 5:26 am

So, in essence fuel costs are all that matters. Investment costs in ancillary equipment above and beyond what fossil fuel plants requires in the grid are just immaterial to wind and solar plants. You sound like an investor in wind and solar plants and wish to minimize the costs applied to those plants. Your view is shortsighted and is very illustrative of your lack of understanding about how complicated and vulnerable an existing grid can be.

Here is an example. Do you know how many additional remote operable switching points will be involved in the grid all the way from the interconnection of a plant to the grid all the way to the end users. Can you define how many combinations of those may be needed to manage the grid under common loads AND when faults occur?

Now I can understand wind and solar providers don’t want to be penalized for additional usage requirements generated by politicians, i.e., EV’s. However, wind and solar should be assessed the extra costs to the grid that are needed for reliability purposes. If wind and solar promotes that they can reliably serve the grid, then they should also be assessed the additional costs needed for keeping the grid reliable.

Reply to  michel
March 18, 2023 12:54 pm

They could have run SA as a pilot program, but they didn’t because they didn’t believe themselves it would work. There’s massive overcapacity of wind and and solar built in SA, and yet at 6:30am wind covered only 60% of the demand.

John Oliver
March 18, 2023 8:43 am

These attempts at integrating wind, solar, battery banks and synchronized connectors, inverters etc etc and some other un perfected just around the corner technologies…. It is really the ultimate real life Rube Goldberg contraption, at tax payers/consumers expense.

John Kelly
March 18, 2023 3:25 pm

A fascinating series of articles. I tried hard to understand it all, but some areas were beyond me. The complexity of a power grid is not to be understated. Clearly adding in all this renewable rubbish increases this complexity to levels where things are still not fully understood. This puts the security of the country and its industry at risk. Who would want to invest in a serious project in South Australia when the grid there has so many flaws?

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