AGL to build fast-start generator to replace 50yo gas plants | RenewEconomy

AGL to build fast-start generator to replace 50yo gas plants

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AGL to replace some ageing Torrens gas units with reciprocating engines, possibly with eye to impending switch to 5-minute settlement.

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One year after AGL Energy’s decision to postpone the planned mothballing of four generating units at its Torrens Island power facility in Adelaide, the gentailer has unveiled plans to replace two of the gas plant’s oldest units with a “fast-start” 210MW reciprocating engine power station, to be known as the Barker Inlet Power Station.

In a statement on Wednesday, AGL said the new power station – set to begin construction in Q3 of this calendar year – would replace two of the four Torrens A turbines, which AGL would progressively mothball from 1 July 2019, once the new plant was complete. The four Torrens B turbines will continue to operate as normal.



AGL said the new plant was specifically designed to provide flexible, efficient and cost-effective “synchronous generation capacity” to the rapidly changing South Australian electricity market, where the 50 per cent renewable energy target had already been met, and surpassed, eight years ahead of schedule.

However, there is confusion about the state’s energy security target policy, prompting AGL to announce just recently that it was suspending investment decisions in the state. Most of the confusion surrounds whether the state is trying to encourage more gas generation, or more battery storage, with its EST.

AGL described the reciprocating power stations as “more efficient” than the existing units, but declined to provide further details to RenewEconomy.

Analysts said, however, that reciprocating engines can use both gas and diesel (possibly economic given high cost of gas), and could be more amenable to the expected shift to 5 minute settlement. However, they provide very little inertia – real of otherwise.

In a statement, AGL said there will be 12 reciprocating engines capable of generating approximately 18MW of output each and “operating at high efficiency with a lower heat rate than other forms of fast-start plant currently available.”

“These units are capable of operating at full capacity within five minutes of start, providing a rapid response to changes in renewable generation supply,” said AGL executive general manager of group operations, Doug Jackson on Wednesday.

The purchase fits in with AGL’s prediction that the energy transition will by-pass baseload gas generation and rely only on peaking gas plants as the energy industry switches from coal to large scale renewables. However, AGL intends to burn coal at the Loy Yang A power station until 2048.

AGL said in December 2014 that it would shutter four out of eight of the Torrens Island power station’s generating units – a group of the plant’s “older units” (built nearly 50 years ago) known collectively as ‘A station’, with an aggregate capacity of approximately 480MW.

“Based on the current market outlook AGL has decided that the Torrens Island A station will be mothballed in 2017,” said AGL Group general manager of merchant energy, Anthony Fowler, at the time, adding that the decision would be reviewed if those conditions – including rising gas prices – changed materially.

Then, in June 2015, the company revealed plans to build a state of the art carbon capture plant at Torrens Island, in a deal with French-based industrial gases company, Air Liquide. The CCS plant was expected to capture and purify up to 50,000 tonnes of CO2 emissions from the 1280MW power station’s exhaust a year.

In a statement this week, AGL CEO Andy Vesey said the decision to move ahead with the Barker Inlet development reflected the company’s long-standing commitment to South Australian customers and to creating a secure energy system as the market transitions away from fossil fuels.

“Torrens A is now 50 years old. Our decision in June 2016 to defer its previously planned mothballing reflected the importance of maintaining security of supply in South Australia following the withdrawal at short notice of other thermal power stations,” Vesey said.

AGL also noted that the gas plant development followed the company’s commitment in recent months “to develop the 200MW Silverton Wind Farm in New South Wales and we hope the 460MW Coopers Gap Wind Farm in Queensland will soon follow suit.”

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  1. Rod 3 years ago

    I find the timing of this announcement intriguing.
    The SA Government must be close to releasing details of their energy plan including the fast start peaking gas plant they intend to own and run for “emergencies”.
    This may be AGL’s way of discouraging such competition.

    • David leitch 3 years ago


  2. David Mitchell 3 years ago

    Outstanding! This is the technology I have been banging on about for ages. The specs sound like Wartsila 50DF’s. These are 17.1 MW dual fuel engines that can burn gas, diesel or HFO. They synchronise to the grid very fast, have black startup capability and can be “switched” on an off the grid in 17.1 MW increments, which means that they are very efficient (ie. they are operating or not). In my view an ideal choice for a state with high penetration of renewables.

    The dual fuel is an interesting choice. These engines operate on a diesel cycle, not with a spark, so you must always use diesel to prime the stroke. However, it provides AGL the opportunity to switch to diesel if there is an attractive price point.

    • Shane White 3 years ago

      OUTSTANDING!!!!!!!!!!!!!!!!!! WTF!!!!!!!!!!!!! New fossil generation is OUTSTANDING!!!!!!!????????????? Jesus H Christ. Where’s your head at David?


      • Leslie Nicholson 3 years ago

        you folks want to sweat in the dark next summer again, this is halfway to a solution. you cannot continue to flog a dead horse, until the CST, batteries and pumped hydro comes online, there has to be a middle ground. the blame game has to end at some point and the system must be fixed

        • Shane White 3 years ago

          Obviously there remains no carbon budget, and even if we accept the dangerous 2C level of warming there is negligible carbon budget remaining. So what do we do? Build a new fossil fuelled power station; DUMB.

          Exactly what problem is this halfway to a solution to?

          FWIW, sweating during summer is quite normal; well it should be.

          • Leslie Nicholson 3 years ago

            lack of supply for one

          • Shane White 3 years ago

            Perhaps we should do without for the sake of a safe climate?

            Obviously what’s needed is a Climate Emergency plan, not an energy security plan?

            Meh, I suppose that coral is under the water mostly out of sight, the Arctic is a long way away, the Antarctic is a bit closer but still far away, and water puts out bushfires so carry on with Business As Usual.

            Our priority IS a safe climate, not the maintenance of high carbon lifestyles. At this rate our towns and cities are going to drown and burn, all because we demanded air conditioning and travel. What a joke.

          • Leslie Nicholson 3 years ago

            shane i am not anti renewable or a climate change skeptic, i want to see those CST’s build and the continued development of wind, solar pv, pumped hydo and batteries. but the fact is since the removal of the norther power plant from the grid the system has become a bit more fragile. so in a sense replacing an old outdated couple of turbines and boilers that take hours to come online with something that is fast and dispatachable that will work better with the renewable systems coming online seems a far more logical thing to do until the storage solutions come online. given they can run duel fuel maybe biofuel is an option down the track as well

          • Shane White 3 years ago

            Leslie I realise you’re not a skeptic but we need to recognise the real emergency that politicians do not.

          • Leslie Nicholson 3 years ago

            i totally agree with you

      • David Mitchell 3 years ago

        :-), I take your point Shane. However, it is way better than building another OCGT. This will use far less gas than the equivalent OCGT, provide better security and as Peter F says, could even be run on biogas or biodiesel in the future.

        I am completely committed to 100% renewables (and soon), but there are technologies that actually make sense in the transition, and this is one of them.

        • Shane White 3 years ago

          Nah David, there’s no time remaining for a gradual transition and half-measures. The science is clear that a step change is needed. We need an emergency declared and a war-like approach to the alteration of energy systems and lifestyles.

          I know this is extreme and sounds like fantasy, but when you consider the changes we’re causing, how earth is responding and the sea level rise expected, I don’t see any alternative apart form giving up.

          Look at the change in CO2:
          And our response is to spend money on a new fossil fuelled power station? That is the action of extremists.

    • Joe 3 years ago

      David I have read the to and fro between you and Shane. The fact is that we have a Planetary Emergency right now and there is no time to muck about with “transitional” gas energy. All that does is prolong the Fossil Fuellers getting in the way of the reaching 100% RE asap. But of course if people don’t want to make sacrifices now then by all means continue with business as usual. The day of reckoning will still come only that the cost in the future will be far higher than the cost of action had been taken right now. This is what The IPCC continually informs us of. I am 59 years old and it really upsets me what I see NOT happening. But the ones that should really be kicking and screaming are the young ones. They will inherit what we have left behind and I am sad to say it is not looking all that promising for their future living on Planet Earth when we are today still mucking about with “transitional” gas energy. Fossil Fuels just have to stop and NOW.

      • David Mitchell 3 years ago

        Joe and Shane, I accept your position. I actually agree that we need to transition as fast as possible, but I also recognise that sometimes pushing too hard can be counter productive. But given your serious commitment, let me ask you a question. I assume you guys are both driving BEV or PHEVs, I’d be interested to swap some tips. I’m driving a PHEV – love it. Never fill up with gas in the city and awesome efficiency on the long trips.

        • Joe 3 years ago

          David I am carless and don’t have a driving licence, its been that way all my life. I cycle and walk around my locality and it is public transport for the longer trips the rest of the time. Look, I’m not perfect enviro wise but I do try to make a difference. I’ve got solar and rainwater tanks. All organic and green waste is composted at home and is fed to the backyard tomato patch each season. The petrol lawnmower really should go…can Elon make me a mower with one of his batteries that I can charge from my solar panels?

  3. DJR96 3 years ago

    So AGL thinks they’ll be running Loy Yang A until 2048?
    They’d be 60-64 years old by then.
    I can understand them wanting to run them into the ground and make as much money out of them as possible. But it goes against everything else they say and what’s happening in the industry.
    Quite frankly they’ll be forced out of the market long before then.

    And I’d have doubts about these proposed units surviving the market long enough too…..

  4. Ray Miller 3 years ago

    Outstanding, at 53% thermal ‘inefficient’ and by the time all other components are included maybe >60% ‘inefficient’. As our carbon budget will need to peak no later than 2020 then head south to beyond zero over the following decades, how does any new fossil fuel generator fit the picture or be part of a plan?
    Oh we of course do not have a plan.

  5. Gary Rowbottom 3 years ago

    Interesting. I’d like to know their emissions intensity. Overall I can live with some gas to replace (some of) the gas we have. But I think it strengthens the case for the SA Government to use its own energy provider tender for solar thermal with storage – Zero emissions, lots of jobs, more than this new AGL plant, even at only 110 MW CST, and valuable exploratory step to reliable energy beyond a heavily gas dependent supply – actual competition for the Big 3 – and with better real inertia (than this new AGL plant) as it happens, regardless of debate about other non thermal types of inertia. Oh and black start capability, heaven forbid we need that. Also as CST would be regionally based another discrete point of supply added, to be more resilient if more towers and wires fall over – now that could happen again. Hopefully that is exactly how the SA Government will see it too.

  6. BushAxe 3 years ago

    Will be interesting to see where AGL’s business plan heads now. They probably shelved the idea of replacing TIPS A with CCGT’s and are now looking at cheaper solar and storage solutions. Hopefully this will build momentum of a serious transition in their generation portfolio towards renewables.

  7. Chris Drongers 3 years ago

    Will AGL get capacity payments for these units or will they be strictly ‘merchant’ generators?

  8. Peter F 3 years ago

    I am not sure about lack of inertia, I can’t find any specific numbers but I can’t imagine why they would be worse than gas turbines.
    They also don’t have a negative output response to frequency fluctuations which gas turbines do.
    Reciprocating engines do have far faster primary response than gas turbines and because each engine can run as low as 20% of rated power or less, vs 30-35% for gas turbines, the standby fuel consumption can be as little as 30 GJ per hour. A 210 MW gas turbine running in Spinning reserve mode will use 800GJ of gas per hour. The gas turbine will take about 10-15 minutes to add 140MW to the grid. This system will take less than 5 minutes to add 205MW.
    Even the capital cost seems to be lower than a gas turbine of equivalent output and there is built in redundancy further improving reliability
    In future it could even run on biogas or bio diesel
    As despatchable backup it is hard to think of a better solution until battery prices fall by another 70-80%.

    • David Mitchell 3 years ago

      The point about reciprocating engines is that when there is lower demand, you turn one of them off!. Let’s imagine you have 10 engines @ 20MW each (=200MW). As demand changes, you turn individual units off or on. So 160 MW demand has 8 engines operating, if demand drops to 135 MW, then you turn another one off. The remaining engines are always running in the efficiency band.

    • Jon Albiez 3 years ago

      I don’t think AGL see the plant being used to any significant level. For meeting sudden gaps in supply reciprocating engines are, as you said, cheap to build and offer scalable response. There will always need to be some form of synchronous generation instantly available to cover contingencies but I could see this plant covering RAISE60 demand.

      • Peter F 3 years ago

        The plant will be significantly more efficient than the current plant so they can run it as more or less contuous load and save gas or as primary reserve with very ramp response

        • Jon Albiez 3 years ago

          Anything on the planet is more thermally efficient than TIPS A. Horribly antiquated units that are past retiring with dignity.

  9. DJR96 3 years ago

    I’m sure the extra capacity will provide comfort and assurance for the state, but it is still not a solution to maintain frequency in any way. 5 minutes may sound like a quick start, which it is for any type of synchronous generation, but it is still woefully slow for providing any response to frequency disturbances.
    Seriously, only battery storage/inverter systems can address that properly. Which makes it the only real route to solving network issues. That’s where efforts need to go.

  10. George Darroch 3 years ago

    AGL are spending millions of dollars on TV ads that tell us that they’re getting out of fossil fuels…

    I’ll believe it when they stop doing the opposite.

    • Shane White 3 years ago

      Hey what’s wrong with spending public funds in 2017 on 12 reciprocating 18MW engines combusting fossil fuel?

      So does anyone know how many pistons each engine has? Did Top Gear ever feature them?

    • Joe 3 years ago

      George you are spot on. The AGL ads sound so warm and fuzzy because the getting out of coal by AGL doesn’t start until 2022 and will take until 2048 before their getting out is completed. I suspect that the way the economics of RE is now working AGL will be “forced out” well before their 2048 plan….which is what is damn well required!!!!

      • George Darroch 3 years ago

        It’s a lot of ‘starting from when five years away when some of our assets reach the end of their useful life’ and they’d have to replace them anyway.

        They know that their consumers want out of coal and are switching to household solar production and cleaner retailers.

  11. George Michaelson 3 years ago

    Are new gas turbines really that much worse than a dual-fuel reciprocating engine? I don’t understand why a GE power turbine can’t spin up in the same window of time that a diesel injected reciprocating engine can, or how a turbine can be worse in power efficiency terms (I thought more of the carnot energy wound up being used in a turbine, than in any other form of gas engine except possibly stirling engines, which these are not)

    • Shane White 3 years ago

      I think we should cease using the term reciprocating and instead use piston.

    • David Mitchell 3 years ago

      The problem with turbines is that the maintenance is proportional to the number of starts, where with recips, it is only proportional to run hours. So reciprocating engines can be stopped and started as often as we like with no maintenance penalty. The other advantage is that when you run a turbine slower than optimum, the fuel efficiency suffers. In contrast, a multiple engine reciprocating plant shuts down individual units, while running the rest at maximum fuel efficiency.

      So to match varying renewable generation, it is more fuel & maintenance efficient to use a multiple engine reciprocating power plant than a turbine.

      • George Michaelson 3 years ago

        great explanation. thanks!

        • David Mitchell 3 years ago

          My pleasure. It’s a little bit counter intuitive, one feels that turbines should just spin up and down, delivering more or less power as required, but (apparently) it doesn’t work like that. Wartsila have quite a lot of good material on their website if you are interested to understand a bit more. They have a particular view of the world, which I don’t always agree with, but there engineering is second to none.

  12. Paulw 3 years ago

    I maybe wrong here but this is my guess on inertia.
    If a generator reciprocating or turbine is capable of providing 20% of its rated output as inertia 1x 200MW turbine could provide 40MW of inertia for a few seconds. 10 x 20MW reciprocating engines maybe able to provide the same amount of inertia.. But what happens when the plant is operating at 20% capacity.
    The turbine due to its physical size might still be able to provide 20% of its rated output ie 40MW. With the reciprocating power plant only 2 x engines would be running at 100% capacity. When inertia is needed the reciprocating plant could only provide 20% of only 2 x generators eg 8xMW

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