Some might contest whether South Australia is still Australia’s leading food-and-wine state, but there is no debate that the state is a key proving ground for the nation’s utility-scale renewable energy boom. As the Clean Energy Council reported in April 2020, “South Australia again got more than half of its electricity from renewable sources in 2019, and is expecting to increase this to 100 per cent by 2030.”
The state’s renewables boom is reducing CO2 emissions and advancing the decarbonisation of electricity generation – it also means that firm generation technology is critical to ensure grid stability. Two key South Australian power stations – Origin Energy’s Quarantine and EnergyAustralia’s Hallett – have recently completed repowering upgrades with the installation of GE LM2500 aeroderivative gas turbines. These innovative turbines draw on the technology inside GE’s airplane engines and can go from cold start to full load in as little as five minutes, giving utility companies the operational flexibility and speed to respond to volatility in demand for firm generation.
“South Australia is seeing penetration of renewable energy more than the rest of Australia and in fact in most parts of the world,” says Bill Truscott, Head of Lifecycle Development Strategy with Origin Energy. “With that comes challenges to the grid: when the sun doesn't shine, the wind doesn’t blow, the power can disappear from the grid very quickly. And we need to have the ability to replace that with stable dispatchable energy. And that’s what Origin does at Quarantine Power Station.”
EnergyAustralia’s Head of Assets Justin Turecek, agrees. “South Australia is actually at the cutting edge of the clean-energy transition globally,” he says. “It is now completely reliant on solar, wind and backup gas – there’s quite a challenge at the moment to figure out how to provide energy, given that we also have to ensure that it’s sustainable.”
Mike Clee, Asset Leaders at EnergyAustralia’s Hallett Power Station, reinforces the issue being solved by the LM2500 fast-start gas turbines: “As the sun goes down or the wind drops off, we lose a lot of megawatts and that'll just break the system. It needs to be perfectly balanced.”
Fast-start aeroderivative turbines support the grid
The flexibility of GE’s aeroderivative gas turbines makes them a unique solution for regions with high penetration of renewables. Regardless of the original equipment manufacturer (OEM) or the generation scenario, GE’s engineering experience coupled with the proven technology of the aeroderivative turbines is delivering repowering solutions to upgrade power plants to enable them to deliver this firming generation swiftly and efficiently.
“The five-minute start capability of GE’s aeroderivative gas turbines gives our customers the flexibility they need to respond fast to the demand, which was critical at both Quarantine and Hallett power stations in South Australia,” explains Mark Benjamin, Aero Repower program leader for GE Australia.
“As renewables uptake increases Australia-wide and the entire industry moves to five-minute trading intervals, this is becoming even more important. GE’s aero derivative gas turbines can go from cold iron to full load in as little as five minutes, which means no costly pre-warming is required. Once online, they can ramp up and down at between 20 to 50MW/minute. We are not aware of any other continuous firm generation technology that can achieve this.”
Flexibility, availability and reliability are essential for firm generation
EnergyAustralia’s Hallett power station plays a critical role in the South Australian electricity grid, providing this firm generating capacity to support renewables; however the existing gas turbines required 15 minutes or more to start. With the LM2500 installed, says Clee, “We can have 30 megawatts on and generating in five minutes from being called.”
This availability is a huge advantage for the grid, as is the reliability. “With aeroderivatives, you don't need to build in redundancy into the plant because they’re so highly reliable,” says Benjamin.
Says Origin Energy’s Truscott, “One of the key requirements of this repower project was to be able to dispatch it from Brisbane.” In the first nine months from commissioning, it was dispatched more than 500 times. “That’s the beauty of aeroderivatives,” explains Benjamin. “If you imagine an airplane engine – it’s made to start multiple times for multiple takeoffs – maybe 10 times a day. They’re engineered to be able to handle that kind of use. So while 500 starts in nine months is a lot, that’s a unique feature of aeroderivative turbines – they are engineered for exactly that sort of operation.”
In-country engineering expertise supports local customer requirements
Benjamin says the two South Australian projects integrated the new LM2500s with existing site equipment, lauding out-of-the-box thinking and capability of the GE engineers to make that possible.
“For Hallett Repower to work we needed a partner that essentially could deliver three things,” says EnergyAustralia’s Turecek. “One was a proven technology, second was a fully delivered contract and the third was a price point that made the project economically viable, and GE are able to tick those three boxes. GE invested the time upfront to understand the existing infrastructure and our needs. The transition to cleaner energy has got a long way to go, but we have worked together collaboratively and successfully to get to where we are today.” The Hallett upgrade was completed in 2020.
At Origin Energy’s Quarantine Power Station, which was completed in 2019, Benjamin says “the scope included changing the rotational direction of the existing generator, installing a customized gearbox to match, as well as engineering and installing a customised adapter plate to fit the turbine to the existing foundations – all under the pressure of an accelerated project timeline. It is the expertise to overcome challenges like this, and the experience of engineering and implementing these repower solutions that gives our customers confidence to partner with GE.”
Australia is at the forefront globally with repowering projects, and “all the GE engineers engineering the solutions for our customers are here onshore,” says Benjamin. “These are complex engineering projects, but we have the capability because of our engineers’ expertise. And having that in-country capacity is a big differentiator for GE.”
Says Origin Energy’s Truscott: “A project of this nature really requires a relationship based on collaboration, trust, innovation, transparency, and above all needs to be wrapped in a blanket of safety as our number one priority.”