Wind and solar replace coal in South Australia. But will the lights go out?

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New report from market and grid operators says South Australia’s push to 50% wind and solar, and the exit of the last coal generator, will not affect system security or reliability. But that is not what the fossil fuel and nuclear lobbies, or many in mainstream media, want to hear.

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South Australia is about to go coal-free, and by the end of the year it will be supplying half of its energy needs from wind and solar. Depending on what you think of renewable energy, this is either another big step into the future, or the beginning of the end of the world as we know it.

The imminent closure of the Northern brown coal power station will signal the last of coal-fired generation in the state. It was to happen in March, but it seems the date has been put back to May 8.

The plant’s owners and operators haven’t said exactly why the closure has been put back two months, but the presumption is that since they dug up a lot of coal from its now closed Leigh Creek coal mine, they have decided they might as well burn it.


The closure of Northern means that the state will rely on its 1,500MW of large-scale wind farms and 680MW of rooftop solar for half of its electricity needs. For the remainder, a collection of gas generators and the interconnector to Victoria will provide the power.

That share of wind and solar will grow steadily in coming years. The Australian Energy Market Operator says the state is “leading the world.” Even Premier Jay Weatherill describes it as an “experiment.”

But will it be a burden of an opportunity? Fossil fuel interests and the pro-nuclear lobby – with the support of much of mainstream media – predict a catastrophe, and appear to wish it to fail. The people who run the grid, the Australian Energy Market Operator, with the possible exception of its CEO, say that it is really not an issue.

A new report was released on Friday by AEMO and South Australia transmission operator ElectraNet and it says – quite clearly – that it is pretty much business as usual. But for a few extreme and incredibly unlikely events that it is obliged to assess, the network is not going to fail. The world is not going to end.

“AEMO has not identified any system security challenges that cannot be managed through existing processes and procedures,” it says.

In other words, there is nothing to worry about. And there is as much chance of a failure in a system with no coal and lots of renewables as there has been in the last couple of decades, when there was lots of coal and no wind and solar.

But that’s not the impression you would get by reading mainstream media and watching some mainstream TV. The Australian Financial Review, which has adopted a particularly hard-line anti-renewables stance, went big on the assumed costs of yet another doubling in network infrastructure.

The AFR quoted AEMO chief executive Matt Zema as saying that the growth of renewables could require “billions of dollars” of investment, that the whole network may need to be duplicated, or possibly torn down.” Interesting.

That is an extreme view and not one represented in the report. Zema is not regarded by the renewable energy industry as a great supporter of their technology, and indeed AEMO went into damage control when queried about his comments by RenewEconomy.

It wasn’t the message they were trying to get across, we were told. “He (Zema) listed a number of other options that were not reported,” AEMO said. Among them, they insisted, was the obvious and cheaper solution of battery storage.

The Energy Supply Council, which represents the fossil fuel generators, also jumped in the game, saying that the report “highlighted the increased risks” of renewable energy generation.

It may be that the ESC – which represents the grim flip-side of the “pro-renewable” public image of AGL and Origin and others – wishes it would, but the report says no such thing. “I can confirm the 2016 report suggests there is no increased risk,” an AEMO spokesman said.

Chris Davies, the head of renewable energy management at AEMO, says there are no technical problems. “The system is secure and we can maintain security,” he told RenewEconomy in an interview on Friday.

Which is not to say that everything is the same. Davies said operating a grid with a high level of renewables is as much a cultural issue as a technical one. It means a different way of doing things. “And we have seen more changes in a short period of time than we have seen historically.”

The study gives two examples of when an extreme event might occur. One is a day when solar PV is producing at near capacity, more than 480MW, and there is no wind, very little demand, no price spikes for gas generators to operate, and the balance of supply comes from Victoria.

In other words, it would require a “bloody hot” day with no wind blowing and somehow no one has thought to turn on their air-conditioner. And then this must coincide with an event when most gas plants and both interconnector links are unavailable. It’s a remote possibility, in the short term, but one that AEMO says it is obliged to consider.

“That’s our job,” says Davies. “The intent of this work is to look at the extremes of system – and test it to breaking point.”

It may just be, thought, that such events do occur in about 10 years time. That’s when AEMO suggests that all day-time demand may be covered by solar PV. By then, though, you would assume they would have begun to integrate battery storage at grid level. They’ve given themselves plenty of warning.

Events that cut the connection to Victoria do happen – nine times since 1999, in fact, and most recently in November last year, when supply was lost for less than an hour. This was despite the presence of coal generation, gas, and wind. Having fossil fuels does not prevent an outage when other things go wrong.

That event in November coincided with another issue in South Australia, which is the loading of “off-peak” hot water, which is automatically switched on around 11.30pm, adding nearly 200MW of demand in a few minutes.

It is a legacy issue of having large coal generators in the system with little demand at night. But this can be addressed by changing the timing of the meters. AEMO is urging the local network operator, SAPN, to use funds granted for that program to go ahead and do it.

That is one solution. Another input into that event was the presence of “non scheduled” generation from smaller wind farms, which presented 75MW of extra output in short order. That issue has now been addressed by making these wind farms “scheduled”, meaning that AEMO is now aware of their planned output.

Another issue that frequently arises is the accusation that South Australia has the highest wholesale prices in the country, and that wind and solar are to blame.

south australia interccontThis is a gross distortion. South Australia has always had high wholesale prices, thanks to its past reliance on expensive gas peakers and Victorian imports, and these prices have actually fallen since more wind and solar meant less gas and less imports.snowtownII20080505_36pm

In fiscal 2015 however, the state’s average wholesale price was $39/MWh, some 25 per cent cheaper than Queensland ($52/MWh), which has no wind energy.

Why was that? Possibly because Queensland relies on gas and its market is dominated by two players – both state-owned generators, who control two-thirds of the market and whose bidding patterns have resulted in big jumps in wholesale prices. The added costs dwarf the cost of subsidies to rooftop solar.

The withdrawal of Alinta and its coal stations means that the South Australian market will be also be dominated by two players – AGL and Engie, which will control 75 per cent of the dispatchable market through their gas generators.

That may eventuate in price spikes, and is what is making large energy consumers fret. Prices rise because gas is expensive, and market dominance means the ability to control the price.

It is an issue, also, for the market for ancillary services, and one reason why AEMO is looking to broaden the options, including sourcing such services from wind farms. But it is a market issue, rather than a technical one.

Indeed, AEMO says the provision of services will be dictated by market factors, and that is the responsibility of other market regulators. It would like to be able to source ancillary services such as voltage, inertia and frequency from as many players as possible. Wind farms might actually be one possibility.

Battery storage, however, appears to be the most likely solution for South Australia, and probably a lot cheaper than building another inter-connector. In Germany, battery maker Younicos says it can provide the ancillary services for the entire grid at a much reduced cost.

Another possibility is to install solar towers with molten salt storage. These plants, operating in Spain for five years, and now being built in north and south America, and northern and southern Africa, provide “base load” or dispatchable power, and at far less cost than the other clean energy alternative, nuclear.

And they will not require the massive grid upgrade and extension that a nuclear plant would require. Indeed, it should be pointed out that South Australia is using the interconnector a lot less than it did before wind and solar.

Ergon is already installing grid-based storage that it says helps it accommodate more renewables and cut network operating costs by one-third. ElectraNet and AGL and others are looking at installing the largest battery storage system in Australia as a fore-runner for the new grid of the renewable future.

This transition to new technologies is the huge opportunity that Weatherill is identifying. If Australia can master this, and there is no reason why it cannot, it can lead the world – as it already has in off-grid and micro-grid technology.

“We are running a big international experiment right now,” Weatherill said. “We have got a long, skinny transmission system and we will soon have 50 per cent renewable energy, including a lot of wind and some solar.

“We need technology breakthroughs for large-scale storage, such as pumped hydro or batteries, but these are massive technological challenges that are exciting opportunities for the state.”

And as for energy security and reliability, this is not just a test of the renewables industry and battery storage, it is also a test of the market operator and other regulatory authorities and their ability to do their job. The world is heading rapidly in that direction. Australia has the chance to lead.

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  1. Beat Odermatt 4 years ago

    A great and level headed assessment of the situation in South Australia. Demand management and demand reduction by using more energy efficient lighting (LED) can help South Australia in becoming one of the leaders in renewable energy.

  2. Gyrogordini 4 years ago

    “…200 MW of off-peak water heating …” Surely a tad of thought might go toward incentivising replacement of those, with solar hot water, and PV-backed day-time resistive and heat pump water heating. Many of those existing HWS will be near end of life anyway – just encourage replacement – AND NOT WITH GAS (as is common in Victoria and NSW).

    • Tim Forcey 4 years ago
      • Gyrogordini 4 years ago

        Err, yes, Tim, that is why I added “day time” . If a consumer can’t work out that solar energy is only available during the day (and therefore the heating would be then), perhaps they shouldn’t have the privilege of access to hot water.

        • Tim Forcey 4 years ago

          Yeah Gyrogordini, I was attempting to reinforce your comment, in a brief statement.

  3. Suburbable 4 years ago

    I’m proud of the efforts my state is making to progress to renewables. That Victorian interconnector has broken down more times than I can remember (even before the inclusion of wind generation into the mix….I’m looking at you, TodayTonight!)

    I believe that once we start using solar thermal or molten salt for generating our baseload we will be all right.

  4. Math Geurts 4 years ago

    Summary: “Will the lights go out?” No because: “For the remainder, a collection of gas generators and the interconnector to Victoria will provide the power.”

  5. Coley 4 years ago

    Guaranteed future headline, major outage, renewables fail WA.

    • Ian 4 years ago

      Oh, you made a spelling mistake its bail out ,not fail.

  6. Ian 4 years ago

    South Australia in its electrical Precambrian times had base coal generation and peaking gas. The balance between generation of power and load was maintained by shifting some load to night time namely off peak water heaters, and using gas generation to cover the peaks in consumption. Coal was the base plate of this system, it was cheap to run and its weakness of invariability was marketed as a strength. At the end of coal’s Epoch, along came wind and solar, both of these produce electricity at no extra cost. Once installed the cost to produce no electricity or maximal electricity is the same. There is now a new player at the base. Instead of the base generation curve being a straight line, it is now an undulating curve following the wind and the sunshine. Coal no longer has a place and is being shut down. Gas still takes on the role of filling the gaps.

    water heating has not changed to take on the role of demand side modulator. 200MW is a huge chunk of SA ‘s load. Instead of soaking up spare coal generated electricity in the night, there are now a few options to manipulate its use. 1. Reduce electricity demand by Modernising the water heating method, instead of the old low tariff resistance heater, install solar thermal heaters, or probably better, install heatpump water heaters, these can even be taken mostly off grid with dedicated solar panels. 2. Shift the time of operation of the remaining old-style resistance heaters to match the availability of renewables electricity. The nice thing about water heating is the storage of energy. This is the cheapest method of storage available, but the caveat is that this storage cannot return power to the grid.

    • Ian 4 years ago

      We have got to explore the concept of ” baseLOAD ” coal power generation is said to be baseload. In the past it provided the anchor function to electricity generation and its characteristic was constant production of electricity regardless of load requirements. Load had to follow generation. Late at night when human activity was limited to sleeping coal power was still being churned out at full steam ahead. BaseLOAD is therefore a euphemism for coal’s weakness not its strength. Coal is not dispatchable, it’s not resilient and its no longer the cheapest kid on the block.

      Wind and solar generation are the new base generators. They are the drums and the rest of the band must follow their beat. Like coal, their characteristics are just as user unfriendly. They produce base power when the solar or wind resource is available. Their production curve is different to coal’s: it’s not a flat constant production, its variable. Unlike coal which produces power at unfriendly times at night, solar happily produces power in the day exactly when it’s needed. Wind is less fortuitous in its production curve but tends to occur at times when solar is not so available.

      The role of gas, hydro, battery storage and interconnectors is to complement the base generator. These things are the other instruments in the band. For the old flat base curve of coal they provided power at the peaks of demand. For the new wind and solar they can fill in the gaps of the base generators undulating production curve.

      There is nothing more virtuous about coal’s generation characteristics, compared to wind and solar, they are just different.

  7. George Papadopoulos 4 years ago

    Giles, wholesale prices may have fallen in SA since the advent of wind, but what’s happening to retail prices? Getting the commodity to the consumer at the right time adds to the cost doesn’t it?

    • Giles 4 years ago

      Yes, South Australia has very high grid costs – always has – it is the nature of their grid, and the regulatory regime that encouraged gold plating. But the network operator has said that they have not needed to spend any extra to add renewables. What extra spending have they made that you know about but they don’t.

      • George Papadopoulos 4 years ago

        So why then are retail prices so high? Why are SA electricity so much higher than other states?

        • Giles 4 years ago

          Read my earlier response. Because they have always had high grid costs, which makes up more than half the bill. Plus, they have had higher wholesale prices in the past because they relied on gas, which is very expensive, and on imports from Victoria. And when wind brought the wholesale market price down, AGL threatened to pack up and leave unless it could redefine the rules around pass-through of wholesale prices. And, as the AER has pointed out, price spikes are being caused because the wholesale market is dominated by just a few players whose practice of “rebidding” is pushing prices way higher than they need be. Sorry George, it ain’t the fault of wind.

          • George Papadopoulos 4 years ago

            And how do the grid costs differ from WA, NT or Tasmania?

            I also though wind energy was “cheap”. Doesn’t SA have the lion’s share of wind energy in Australia.

          • Steve Applin 4 years ago

            I ‘ l l
            s p e a k
            s l o w l y
            f o r
            y o u
            G e o r g e.
            W h o l e s a l e
            p o w e r
            p r i c e s
            ( i e w i n d )
            a r e
            l o w.
            N e t w o r k
            ( ie p o l e s, w i r e s)
            p r i c e s
            a r e
            t h e
            p r o b l e m.

            Understand now?

          • George Papadopoulos 4 years ago

            So Steve, what makes network costs so much more expensive in state that has the “cheapest” form of energy?

          • Steve Applin 4 years ago

            Cost of generation and cost of transmission (from the power plant to your house/business) are separate matters. One company owns the generation equipment, another owns the poles and wires. A third retails to you.

            The transmission people gold plated their network and assumed ongoing large increases in demand. The demand has actually fallen leaving the higher fixed cost to be recovered from less electricity, which increases prices.

            I hope that is simple enough for you.

          • George Papadopoulos 4 years ago

            So Steve, you must by now get my point: “cheap” wind energy ends up very expensive by the time it gets to the consumer: you simply can’t have an intermittent source of energy and expect other base load sources and interconnector resources to provide energy on demand unless you are prepared to pay a price that incorporates the reality of the situation: wastage and inefficiency. Wind blows = energy is cheap – wind doesn’t blow energy costs a premium.

            Should I now spell that only very S L O W L Y to you?

          • Steve Applin 4 years ago

            AS u suspected you are VERY VERY obtuse. ALL generation in SA is cheap, it’s the transmission that is expensive. I know I’m an accountant and have a better understanding of cost than most, but surely the distinction made in the article, by Giles then me is not that hard to grasp.

          • Steve Applin 4 years ago

            WA has very high transmission costs despite renewables being about 10% and no interconnector. Same problem: gold plating and over building.

          • George Papadopoulos 4 years ago

            Steve, given that you claim you’re an accountant, you should reasonably understand that concept of getting a product to its market is key in determining retail cost.

            I am so sorry that you resort to personal insult – small mind?

        • Giles 4 years ago

          And from the last AEMO report on South Australia retail prices. Grid costs make up 52% of bill and are rising. Wholesale costs:

          Wholesale energy costs are expected to fall by around 20 per cent in the South Australian region across the reporting period due to a growing oversupply of generation capacity. The oversupply is a result of falling energy consumption and growth in renewable generation under the Renewable Energy Target, most of which has occurred in South Australia.
          Low wholesale energy prices offset the costs of the Renewable Energy Target for South Australian consumers.

  8. Malcolm M 4 years ago

    Back in November 2015 when there was load shedding in SA following an outage of the interconnector, the gas peakers were VERY slow to respond. It took over an hour to get some of them started, and some such as Dry Creek didn’t start at all. Why did so much capacity go missing ? In modern control systems, such as operates the Mortlake gas power station in Victoria, the generators can be started remotely and achieve full power within 5 minutes. Surely this “vanishing capacity” issue needs to be looked at, perhaps incentivised through availability payments that are paid only when the generator responds successfully to drills.

  9. George Papadopoulos 4 years ago

    Here’s the Australian Financial Review on the topic. Very different story to that of Giles!

  10. riley222 4 years ago

    All I can say is in Oregon my revered Mother in law pays about 14c US for lekky.
    WTF is wrong with the way we do it.

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