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Gas turbines vs battery storage: S.A. in state of inertia over energy future

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It is not hard to understand why the South Australian government does not want to take any chances over electricity supply. They feel badly let down – in the middle of a storm and in the middle of a heatwave – by the Australian Energy Market Operator, screwed by the profit motive of fossil fuel generators, and betrayed by the federal government.

And they feel exposed. By their admission, they are leading the world on the adoption of wind and solar, which is inspiring for most, except for when the lights go out. And it is highly political. What happens next summer could decide the fate of the next election, due to be held in March 2018.

So it’s no surprise that South Australia has taken action of its own: giving emergency powers to the energy minister, ordering a new back-up generator, announcing the country’s biggest battery storage tender, and proposing to introduce an energy security target, which sounds like a great idea to guarantee dispatchable generation, loosen the hold over the market of a few incumbents, and lower prices.

But has South Australia been sold a pup by the fossil fuel incumbents on the issue of inertia? As we reported on Thursday, South Australia’s draft rules for its energy security target appear to rule out battery storage as a source of dispatchable generation.

It favours what it calls “real inertia” provided by turbines, which, in South Australia right now, means only gas-fired generation. Synthetic inertia, often described as fast frequency response, and which would likely come from battery storage usually paired with wind and solar, does not qualify.

It’s a decision that will provoke howls of protest from the battery storage industry, and has implications for the owners and developers of existing and future wind and solar farms.

Some have already reacted, with Tristan Edis, from Green Energy markets, labelling it as a daft idea, poorly designed and entrenching a lack of competition – the very thing the state government should be trying to avoid. And there have been many similar responses in the comments section of our article on Thursday.

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The issue of inertia, and what can provide it, and overall system security, looks like tracing the same evolution as the debate over renewable energy. Go back a decade, and many engineers were saying it was impossible to incorporate more than 10 per cent wind and solar into the grid without having the whole thing collapse around them.

Now, say the CSIRO and Energy Networks Australia, between 30 and 50 per cent wind and solar can be considered trivial, such are the technology developments and progress in grid management. The CSIRO and the networks, even the big gentailers like AGL, are freely talking about 100 per cent renewable energy within a few decades.

“And once we have the storage capacity to get us to 50 per cent (renewable energy), we will have the technology to go to 100 per cent (renewable energy),” AGL CFO Brett Redman said in a major presentation last week.

South Australia now finds itself at that pivot point. It’s already got 50 per cent wind and solar and has a whole bunch more coming on to the grid in the next 18 months. Having lost faith in the centralised authorities, it is now trying to manage its own needs. The fate of power system security, and the careers of politicians, depends on it.

In the case of inertia, it does seem to be a battle between “real inertia” – that provided by spinning turbines – and synthetic inertia, also known as fast frequency response, and generally provided by battery storage, often paired with wind and solar.

It is also a battle of two grid management philosophies: the old style, which is to respond to every problem or challenge by generating more of something and shoving it into the system, however slowly; and the new style, which is to think about management by being smarter, and more efficient. That’s where fast response and smart software come into play.

“Inertia is not the goal, frequency and voltage stability is,” writes engineer Peter Farley. “Arguing for more inertia is a bit like saying heavy cars are safer than small cars in some accidents so all cars should be as heavy as possible.”

Right now it is accepted that fast frequency response (FFR) and battery storage can play a significant role in the provision of inertia and the management of the grid. It fills in the gap between a major fault and the relatively slow response of the governors that control the gas turbines.

That means less “real inertia” is needed. This has been found in the ERCOT system in Texas, and by research from AEMO in Australia. But it is not thought that FFR can completely replace “real inertia”, or at least not yet.

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This graph from an AEMO presentation (slide 19) last year neatly summarises the issues. The debate has moved from “synchronous only” to a mixture of synchronous and fast frequency response (synthetic or storage), and will eventually evolve even further.

This report was followed by another report released by AEMO in March, which followed a consulting report by GE Energy. AEMO’s conclusions were:

FFR and synchronous inertia are technically distinct services due to the timescales over which they act. This means a minimum quantity of synchronous inertia will continue to be required in the short to medium term. However, FFR can compensate for, and help to mitigate, the effects of reduced synchronous inertia on power system frequency control by providing a wider range of options for meeting the frequency operating standards (depending upon a co-optimised consideration of the availability and costs of both services). This suggests that enabling FFR services in the NEM may allow the frequency operating standards to be met with a lower level of synchronous inertia.

So, it seems, the key question is what is a “minimum quantity” of real inertia.

Right now, that is up for debate, just as the total requirement for inertia is also up for debate (see this submission from two weeks ago by AEMO). But the feeling is that the minimum quantity of “synchronous” or “real” inertia it is less than the 36 per cent that South Australia is demanding from July 1, rising to 50 per cent by 2025.

The fear for the industry is that South Australia is raising the drawbridge against synthetic inertia and battery storage too quickly, possibly because the gas generators have put the fear of god, and more blackouts, into them.

It’s understandable that the government wants to take no chances, but if it wants its legislation to be cost effective, and not create a new series of stranded gas generators, it needs to work out exactly what it wants to achieve.

The draft legislation, and the apparent decision to rule out synthetic inertia will have significant impacts on the owners and developers of wind and solar farms, which were looking to pair with battery storage to provide some of those market services, and to make their output “dispatchable.”

And Farley, like others, warns that just relying on gas turbines is not a panacea, simply because their response is often too slow – an issue raised, but not fully explored, in the September 28 “system black” in South Australia.

“There is a good argument to suggest that a system with a large proportion of gas turbines is possibly more vulnerable to short-term instability than a modern renewable based system with storage,” Farley writes.

“Probably the most expensive, least reliable way to supply grid stability is by adding gas turbines, if the primary purpose is to add inertia.”

The CSIRO and ENA report into  a zero emissions grid looked at the issue of inertia and concluded that – while more analysis is needed – there are a range of technical solutions to achieve inertia and frequency management outcomes in a high renewables grid.

csiro south oz“While battery storage is forecast to provide the dominant new source of energy balancing, there are a diversity of potential solutions which could be employed as alternatives while still achieving zero net emissions depending on their changing economic potential.”

The report specifically looks at the scenario where South Australia is sourcing 80 per cent of its demand from local wind and solar.

“Far greater levels of monitoring and control will be required to allow active management of the distribution network to meet its increasingly complex operational needs. This will require consistent, open and flexible systems, with suitable communications and open standards to permit new market entrants to participate.”

Iain Macgill, from UNSW, says that real or synchronous inertia and synthetic inertia aren’t direct substitutes. “However, there is a relationship. Other things being equal, synthetic inertia and very fast frequency response equipment can generally reduce the need for inertia while not being a direct substitute.”

But he agrees with Farley, and others, that relying only on gas turbines is not fool-proof either.

“Some of the most sensitive equipment to high Rate of Change of Frequency (RoCoF) events in a power system (the thing that inertia helps reduce) may actually be particular types of thermal generating plant (hard to know given that we generally have so few high RoCoF events).

“So there might be particular circumstances where the synchronous generators are providing inertia, but also set the requirement for inertia, and are unable to deal with high RoCoF from insufficient system inertia should there be a disturbance. If they fall off-line they will further add to the frequency disturbance and we are on our way to collapse.

“Who knows – it might actually prove easier in the longer term to manage power systems with fully power electronics interfaces than a mix of old synchronous plant and new power electronics interfaced plant. Lots of interesting research questions needing to be addressed.”

To be sure, this legislation – as it is – could encourage renewable energy providers of “real inertia” such as solar thermal and pumped hydro into the system. But these won’t be built for several years.

Small grids can operate quite satisfactorily without turbines, but every scenario for a 100 per cent renewable grid envisages a certain amount of spinning turbines coming from hydro, pumped hydro, solar thermal or bio-gas. But they also envisage significant amounts of battery storage.  

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  • Robin_Harrison

    Does this mean FFRs are not allowed to respond quickly to shortages on the grid? If they are allowed, any FFR could compete well with the gas mafia as they attempt to manipulate prices.
    It may not need govts, the price is right, almost.

    • Greenfanatic

      The key points to understand:
      When the shortage of generation happens, the synchronous generator releases the kinetic energy stored in rotating mass so that abrupt fall in frequency (rate of chage of frequency,RoCoF) is limited. Once the fall of frequency is detected, local governor controller allows more mechanical energy into the turbine, accelerating the rotor speed. As the rotor accelerates, the fall in frequency is arrested. Then the frequency starts rising up from the minimum point (nadir) till new steady state is reached. Thus, the inertia gives enough time for governor control action before frequency fall below the specified limit. High Roof is not desirable as it produced high transient flux in the synchronous machine. This can damage the machine auxiliary services too. When inertia is reduced after high penetration of renewable, frequency control becomes difficult because of high RoCoF.Fast Frequency Response is the technique where wind and other storage boost their output for a while to compensate the generation shortage. However, wind generator needs recovery period to gain pre-fault level rotor speed if it is not operating under reduced power mode.

      • Greenfanatic

        FFR can be available within couple of seconds.

        • DJR96

          FFR (bi-directional battery storage inverters) can respond within MILLISECONDS.

          • Greenfanatic

            Agreed, the main point to be noted is that the contribution from inertia lasts around just 10 sec in the typical power system after the fall in frequency starts, then generation has to increase the power from governor action .The synchronous inertial response (SIR) comes into the picture only up to 10s to restrict RoCoF before the governor action increases the output. This is only true in case of credible contingency where power system is supposed to be stable.
            The loss of generators which have governor control with large head room and connected in AGC are more critical and crucial than the inertia (SIR).

      • Ren Stimpy

        You Green fucks haven’t a leg to stand on. Just step out of this problem with your moralising and we will solve the problem twice as quick without your vaginarising

    • Greenfanatic

      FFR are best suited for those responses than the synchroneous generator as they can be tailored to the system need. You can use it for 20 minutes or for just 20 sec.It can respond within milli-seconds.All wind and PV in Australia are not required to have these capability to the date. Hence, it is up to the policy maker but technology do exist.

  • howardpatr

    Given the cost of lithium-ion batteries in EVs South Australia should perhaps be wary of Musk/Tesla. Better and cheaper large scale ESS options might be closer than we think.

    https://www.eosenergystorage.com/

  • MoreBikesPlease

    SA could have kept the turbines from Northern Power Station and spun them as a synchronous condenser, not burning fuel. That would have provided inertia. SAPN mentioned this in a document. It’s been done in other countries:
    http://www.powermag.com/aes-uses-synchronous-condensers-for-grid-balancing/

    But in the current market this cannot happen, because no individual company can make money from it.

    • Rod

      Torrens Island A station is probably the next to retire. They would be a good candidate.

  • Peter

    Why are politicians, accountants and lawyers making engineering decisions?

    • Miles Harding

      And the politicians are virtually all lawyers of one sort or another, so it’s actually only lawyers and acountants running the show!

      Letting engineers and physicists (ignore Malcolm Roberts) in to the process would result in a pragmatic solution being proposed and settled within weeks. The pollies would be out of a job.

      • Peter

        Is Malcolm Roberts a physicist? (ROFL)

        • Peter

          I looked him up:

          B. Eng. (Honours) (UQ).
          MBA (University of Chicago Graduate School of Business).
          Vineyard labourer, 1973.
          Coal face miner underground, 1977-79.
          Mining engineer, 1979-83.
          Mine management, 1983-84.
          Mine manager, 1984-88.
          General manager, 1990-93.

          Still laughing!

          • Just_Chris

            Sorry commented before reading,

        • Just_Chris

          No Malcolm Roberts is a dickhead – sorry – I mean a geologist with an MBA which qualifies him to comment on climate change. He may also have a physics qualification but really all that means is he has been to university and got a degree it doesn’t make him any smarter.

          • Joe

            The Roberts is a bit of a contradiction. For a dude that is schooled in the sciences he takes positions that are at odds with science. His nonsense line of “show me the empirical data” is an excuse to hide his own ignorance or just plain non acceptance of the science. I think his past connections with Coal probably explains everything we need to know about the dude.

        • Joe

          He is an “Empiricalist”

    • Robin_Harrison

      Because engineers don’t understand bribery and corruption.

  • Peter G

    I’d be interested to know what, if any, influence the Heywood AC inter-connector on this policy choice.
    Is it that the imported frequency from Victoria is ‘Fixed’ and the “Phasorpoint” system attached to Heywood detects local frequency mismatch relative to the imported frequency?
    If this is the case is there an optimal quantum or quality of local SA inertia required to detect rates of change so to manage inter-connector flows?

    • Greenfanatic

      The Heywood inter-connector may go out of service if the power imported exceeds its designated capacity or because of other reasons. In this case, SA power network will be islanded and has to operate on its own. In that case, system operator needs to generate the extra power equivalent to the import from Heywood interconnector to make balance between generation and demand. If the demand exceeds, frequency starts falling.

      • Peter G

        Yes voltage sag would prompt increased power flows and may trip the connector. But I was hoping to explore the effect of a strong “fixed” frequency supplier like Heywood on local frequency control in SA? I imagine the supplied frequency from Victoria will not appreciably slow in response to increased demand in SA. So to take your earlier point that frequency control system is currently
        predicated the dampening response of available rotational interia to changes in demand, how do they do it in SA? If Heywood was DC South Australia would ALWAYS be islanded with respect to frequency. I was wondering if, and how, the AC coupling to the NEM is perhaps also contributing for the desire for ‘real’ local interia?

        • DJR96

          You’re right in so much that Heywood provides a relatively rigid frequency. If SA has a major sudden fault like a generator fail, SA doesn’t have much inertia to resist RoCoF and has to lean heavily on the Heywood interconnector. But that can only supply so much power and what happens is that SA effectively becomes out of sync with the rest of the NEM and that will trip the interconnector rather than just the overload. This is exactly what happened back in September 2016 which resulted in the whole State black system.

        • Greenfanatic

          Let us look at the time frame of the frequency control.The main point to be noted is that the contribution from inertia should last around just 10 sec in the typical power system after the fall in frequency starts, then generation has to increase the power (most of the time from governor action) .The synchronous inertial response (SIR) comes into the picture only up to 10 sec to restrict RoCoF before the governor action increases the output. This is only true in case of credible contingency where power system is supposed to be stable.
          The loss of generators which have governor control with large head room and connected in AGC are more critical and crucial than the inertia (SIR).

          • Greenfanatic

            When supply and demand are in perfect balance, the mechanical input and electrical output are in equilibrium. When there is change in electrical output, the mechanical rotor either starts to accelerate or decelerate to respond the increase or decrease in electrical output. This is called inertial response. This response last for few seconds and system has to gain new steady state otherwise system becomes unstable. NEM has 6s, 60s and 5 minute FCAS provision to balance frequency. Having said that, inertial response is crucial up to 6 seconds after the contingency.At 6 second, the NEM responds by increasing the generation

          • DJR96

            The whole notion of inertia and frequency control can and will be completely obsolete if we choose to. The powers that be are slowly coming around that we can’t rely on synchronous generation forever. See my post below re ‘frustrating to watch’.

            The point is that solid-state converters (bi-directional inverters with battery storage) can respond instantly and never allow frequency to deviate at all. Making all forms of frequency regulation redundant and obsolete. Only then will we have a truly stable, reliable and secure electricity network.

          • Greenfanatic

            Yes, you are correct. I have heard some experts tired of trying to convince politician for new HVDC line. A HVDC line from QLD to SA covering Cooper Basin (which has potential of 10,000 MW geothermal) will be best suited for current problem at SA and future geothermal generation.The experts say no body try to understand it. Looks like no body in policy level want renewable generation.

          • DJR96

            If that much thermal can be accessed AFFORDABLY, then yes there could be a case for a HVDC interconnector.

            But do bear in mind that even SA has enough generation and continues to build more renewables too. We don’t need to transfer any more energy between States, and therefore can’t justify the huge expenditure.

            Conventional generation will continue to be displaced from the market. It will all be retiring in due course anyway. So renewable generation will replace it where ever it is needed and is able to use the existing transmission and distribution networks. All it needs is to be complimented with battery storage at scale, comply with connection standard I’m proposing, and you have the best network in the world.

            I/we will continue to push this as a policy for politicians to take up. The best bit is that the economics stack up and we don’t even need to worry about the environment or EIS’s etc.

  • Miles Harding

    I can’thelp thinking the real inertia is between the ears of the network operators.

    We are watching coal being both priced out of the market and technically incapable of operating as the duck curve forces it to shut down each day. It will require agressive interference to maintin a place for coal into the near future.

    Something similar will happen with gas. SA already has supply issues, and these are unlikely to ease in future, particularly as the neighbour states will doing the same thing and ramping their gas needs in response to the same issues that are forcing their own coal into oblivion.
    I would not be surprised if overall gas supply issues are so severe by 2036, that little is avilable for peakers and they will have to run from very limited fuels, such as bio-oil.

    Either way, becoming highly dependent on gas generation is a folly that SA doesn’t have to fall victim to.

    • DJR96

      2036? The crunch period will be 2018-2020. After that the increase in renewables available will relieve demand on gas. So the gas situation is pretty urgent, but gets better.

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      • Miles Harding

        Howard Kunstler wrote a book titled “The Long Emergency” about surviving cacading catastrophes as we are forced from our comfortable perch by the deline and ultimate end of cheap energy.

        We should be looking at this year’s panic being just one in a series of such emergencies that will ultimately force us to a sustainable pathway.

        As I see it, we have two choices:
        a) to continue as we are and suffer each catastrophe as we encounter it or
        b) to change track and lead the way to the same future.
        The latter requires moral courage and leadership, which is virtually non-existent in today’s politics. :-p

        Another aspect is that each catastrophe erodes social and financial capital, whereas leading the change has the possibility of building capital. While we arrive at the same end point, our current path leaves us exhausted and impoverished.

  • Greenfanatic

    The key points to understand:
    When the shortage of generation happens, the synchronous generator releases the kinetic energy stored in rotating mass so that abrupt fall in frequency (rate of chage of frequency,RoCoF) is limited. Once the fall of frequency is detected, local governor controller allows more mechanical energy into the turbine, accelerating the rotor speed. As the rotor accelerates, the fall in frequency is arrested. Then, the frequency starts rising up from the minimum point (nadir) till new steady state is reached. Thus, the inertia gives enough time for governor control to act before frequency fall below the specified limit. High RoCof is not desirable as it produces high transient flux in the synchronous machine. This can damage the machines in the auxiliary services too. When inertia is reduced after high penetration of renewable, frequency control becomes difficult because of high RoCoF.Fast Frequency Response is the technique where wind and other storage boost their output for a while to compensate the generation shortage. However, wind generator needs recovery period to gain pre-fault level rotor speed if it is not operating under reduced power mode. FFR can be available within couple of seconds. The issues is the intermittency and uncertainty in wind and PV. Secondly, non of WTG and PV require to have FFR in Australia to the date. The cost of retrofitting, accurate forecasting of available FFR and opportunity cost of lost generation (if wind and PV are operated at reduced power mode than available to provide enough headroom) are yet to be studied .

    • DJR96

      Yes you have described how it works pretty well, however, there is virtually no constant live governing of turbine speeds at all.

      Maintaining frequency (turbine/generator rpm) can best be described as a clumsy balancing act of two blindfolded people standing on a see-saw. If one moves the other has to sense which way and react accordingly.

      So even if something untoward happens to alter frequency, nothing actually responds other than when AEMO dispatches generators to provide more power. Very clumsy, no automatic system at all.

      • Greenfanatic

        Agreed, the main point to be noted is that the contribution from inertia lasts around just 10 sec in the typical power system after the fall in frequency starts, then generation has to increase the power from governor action .The synchronous inertial response (SIR) comes into the picture only up to 10s to restrict RoCoF before the governor action increases the output. This is only true in case of credible contingency where power system is supposed to be stable. The frequency stability is defined as its ability to regain acceptable steady state value after a major or large disturbance in power system. This major or large disturbance is credible contingency ( it is generally taken as the single largest loss of generating station or a importing transmission line which is bigger.
        If the contingency is bigger than the credible contingency( (N-1) criteria), its the matter of reliability.
        The loss of generator have governor control with large head room and connected in AGC are more critical and crucial than the inertia (SIR).

  • DJR96

    This is frustrating to watch.
    Virtually all the issues AND the solutions are mentioned and being discussed by all the powers that be. But they aren’t putting the right pieces together to form a solution.

    The question above is not how much synchronous generation is required to maintain security, it should be how much FFR is needed.

    As has been demonstrated in SA, there are times in SA where less than 25% of their supply is from synchronous generation and they have been running just fine.
    Now if 25% of their capacity (not supply) was via bi-directional battery storage operating in a fixed frequency mode (just like being off-grid), it would form the grid and force all other generation, including synchronous, to operate at the same frequency. Exactly 50Hz without any variation.

    This can’t actually be done NEM-wide until there is 5-6GW of inverter capacity (not necessarily that much battery storage capacity though). But as soon as there is, a switch could be flicked to change the operating mode of all those inverters.

    All that is needed is a battery connection standard that requires any battery storage over say 1MW to have this capability. And to do this they would need to have a device that synchronises the output with GPS time signal, thus keeping them all perfectly synchronised. All the elements of this technology already exists, it just needs to be put together correctly.

    And that folks is how we can use any combination of any type of generation, even 100% renewables.

  • Peter G

    Thanks Giles. Last months AEMO report you cite rather cryptically suggests that:
    “In theory, transient stability constraints can have negative inertia terms, meaning that a higher inertia (in the importing region) can cause the constraint to bind more. This may have unintended and complex implications. However … this is not likely to be a significant issue in the near term.”

    Inter-connector constraints would be an extra bonus for SA gas and a loss of access for SA wind to the wider NEM.

  • John Gare

    Giles, A layman and solar thermal tragic, I ask why ‘these won’t be built for several years”? I think construction time must be under 4 years by now, especially with steam-trained work force presumably still around Port Augusta.

  • Nick Sharp

    I wonder how this “must have REAL inertia” idea would be playing out if key SA ministers had a science (or STEM) degree. I note Hon Tom Koutsantonis’s education included University of Adelaide, but unlike many in Fed or NSW parliaments I cannot find any indication of his courses.

    I feel we are really badly served by our parliaments given the paucity of STEM qualifications among the members. As I explained in this ABC RN broadcast:

    Science literacy in Parliament
    http://www.abc.net.au/radionational/programs/ockhamsrazor/science-literacy-in-parliament/8142506

    there are just 20 members and senators in the current federal parliament with STEM tertiary qualification. True, they have sources of scientific advice, but are they seeking and accepting it?

    Major data centre managers could tell them “No, we don’t keep the diesel generators spinning all the time just in case the mains fails. We have a battery bank and all the convertors to ensure (a) we get exactly 50Hz power all the time and (b) INSTANT continuation of power from the bank if the mains fails; not even a glitch on the 50Hz waveform. THEN we turn on the diesels in case the outage lasts longer than our batteries.”

    Sigh …

    • GregS

      Well said…when you don’t understand the things you are trying to legislate, it is easy to be led astray.

    • Andy Bowe

      He then had to leave University before completing his degree to help run the family small business due to an illness in the family. On his ministerial site.

  • Craig Allen

    Could flywheel energy storage be deployed as an energy storage solution that satisfies the inertia requirement?
    E.g. http://beaconpower.com/carbon-fiber-flywheels/

    • Peter F

      Yes they are m uch more cost effective than rotary synchronous condensors

  • DAE

    flywheels are excellent for ultra fast – real inertia. the duration they can respond for is typically very short. Hydropower units are the source of most real inertia for both fast and ultra fast response.

  • DAE

    All of these discussions are very good and technically have truth in them but what everyone is failing to ask “how is the grid handling it now” and “how much that cost”. Electrical Physics dictates that synchronous MWs with Inertia are required to hold frequency and particularly to ride thru a fault transient (synthetic inertia can also do some very positive things but it is pretty expensive to add those positive things). Refer to NERC North American reliability council SIR studies and well as recent studies by ENTSOE. I don’t know this specific grid and the devil is always in the details but I can tell you that when you look around the world, it is the FFR capability of Large Hydropower (storage hydropower) and particularly large Pump Storage hydropower that has great inertia that is saving the grids from collapsing due to frequency problems on a daily basis. When organizations make claims that over 20% renewable penetration is possible, they are almost always including LARGE Hydropower and PS in the definition of renewable. I have given presentations around the world on how the Pump storage and hydro fleet in general responds every day and in emergencies. When Non-firm renewable are more than 10%, the average number of starts and stops of a Hydro unit at a PS site or a storage dam more than quadruple from there original design intent. FYI – The fastest responding Power plant in the World is Dinorwig Pump storage in Wales UK and it can respond at the plant level with a ramp rate of 180,000 kW per second. (not minutes) for the entire 1600 MW plant capacity. Australia has more than 1600 MWs of operating Pump storage at 3 plants and quite a few other conventional Hydro plants with very good FFR capability and I am sure when you look deep that they are saving the grid on a daily basis from frequency disturbances. Unfortunately Pump Storage suffers from the fact that it is old technology, that it just works and it is typically defined as Generation instead of storage so it is ignored and forgotten about by the public. The one group that never forgets is the control room operators who have to respond and make fast decisions. For this reason almost all Islanded grids in the world, including Australia, have operating Pump Storage Hydro and most are looking at building more plus Batteries which definitely have there place in the grid mix. See recent May 2017 Power Magazine article http://www.powermag.com for some hard data on PS construction. Recent studies have shown that Battery storage is 3 to 4 times more expensive than PS hydro when you consider its lifetime cost. Batteries can have a lower initial cost but Pump storage hydro has a 75 to 100 year life and batteries are much much shorter (numbers vary by how often they are used) and long term over their life batteries also lose on a carbon footprint basis as well.

  • Leon

    Surely the gas generators, like the SA govt owned (proposed) gas generator, would want to have their own batteries for very fast frequency response. They can bring in their generators in an unpanicked manner to maintain the frequency support and recharge their batteries. Helps them make better use and more $ out of their asset which should be running at lower and lower capacity factors as the amount of wind and solar increases. Doesn’t seem crazy to me. Seems like a way to make the fossil fuel backup generators pay for themselves a bit better.

    Perhaps Koutsantonis has had someone in his ear along these lines.