Australia’s largest solar farm registered in troubled part of the grid

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After much hard work, Australian renewables developer Edify Energy and UK-based investor Octopus have announced that the Darlington Point Solar Farm in south-west New South Wales (NSW) has achieved registration and become the largest solar farm connected to the National Electricity Market (NEM). With two synchronous installed onsite, the 275MWac/333MWdc PV project is expected to add further system strength in a troubled part of the grid, known as the West Murray Zone (WMZ).

With the generator registration completed, the Darlington Point project is allowed to begin the commissioning process. Welcomed as yet another important milestone towards unlocking new generation in the WMZ, the announcement comes hot on the heels of the registration of the RWE Renewables-owned 220 MW Limondale Solar Farm, located near Balranald in south-west NSW, announced in July.

The Australian Energy Market Operator (AEMO) is clearly moving in leaps and bounds towards its goal to unlock new generation in the region where all connection work came to a complete halt after radical curtailment was imposed on five operating solar farms last year. The Bannerton, Broken Hill, Gannawarra, Karadoc, and Wemen solar farms were curtailed to half of their output for seven months due to system strength issues in the WMZ region.

However, following the successful implementation of new control firmware and settings developed by Germany’s SMA, which involved tuning the solar farms’ inverters to operate in concert, rather than individually when delivering clean energy to the grid, AEMO was able to get on with the WMZ pipeline of projects. With its two syncons, the Darlington Point Solar Farm is expected to improve system strength in the region and help AEMO and TransGrid manage the ongoing integration of renewable energy generation.

“The issues identified in the West Murray Zone have made it more challenging to meet the connection requirements for new projects, so we especially appreciated the collaborative and responsive approach adopted to solve the technical challenges that arose,” AEMO’s Chief System Design & Engineering Officer, Alex Wonhas, said.

South-west NSW grid conundrum

The issue of stability in the south-west NSW power system has been raised by state network owner Transgrid, which is currently seeking submissions from proponents of non-network options that could improve the situation in the region where the high quality of renewable energy resources has attracted a lot of interest from investors.

The Broken Hill Solar Plant (53 MW) and the Silverton Wind Farm (200 MW) connected at Broken Hill in December 2015 and May 2017, respectively. More recently, new solar farms have been connected at Coleambally (150 MW) in November 2018, Griffith (29.9 MW) in April 2018 and Finley (133 MW) in late 2019. In addition to the Darlington Point Solar Farm, further connections are progressing with commissioning scheduled during 2020 for Limondale 1 Solar Farm (220 MW), Sunraysia Solar Farm (200 MW) and Limondale 2 Solar Farm (29 MW). In summary, there has been approximately 560 MW of renewable generation connect in this area since December 2015 with a further 800 MW to be connected by 2021.

In its latest analysis, Transgrid highlighted the risk posed by the commissioning of new generation in south-west NSW that is expected to result in high power flows east towards Wagga Wagga from mid-2020. With the existing power lines overloaded, the network owner has warned about “a particular risk of fast voltage collapse that would result in power electronics-based renewable generation becoming unstable” and would lead to “material constraints to some generators in the region.”

To stop too much electricity from flowing east, a new limit could be imposed in the region at approximately 300 MW. However, power flows east presently peak at approximately 200 MW and a further 724 MW of generation is due to be commissioned over 2020, which makes it unlikely that all major projects in the region will be allowed to simultaneously generate at full capacity.

Solar in, coal out

Aside from a 475 MW connection application that is in the works, the Darlington Point Solar Farm is the biggest project in south-east NSW. It features nearly one million solar panels spread over 1,000 hectares and will provide cheap, clean green energy to over 110,000 NSW homes. At the peak of its construction, the project provided more than 700 jobs including many local ones.

The project has a signed PPA with Delta Electricity, Vales Point coal-fired power station owner, for 150 MW AC or approximately 55% of its output, demonstrating the growing place of renewable energy. “Solar farms of this scale will be essential to filling the gap in power generation that will soon emerge as more of Australia’s ageing coal fleet retires, especially in New South Wales,” Octopus Investments Australia Managing Director, Sam Reynolds, said. 

For Octopus, the UK’s largest solar investor, which has rebranded itself as Octopus Renewables last year, the Darlington project was its first deal since it had set up shop in Melbourne in 2018. But its clean energy ambitions in Australia have been growing ever since.

“AEMO’s latest Integrated System Plan aligns with our ambitions – to finance the urgently needed expansion of renewable energy in Australia. This comes with the challenge of ensuring the new generation can operate reliably on the power grid and maintain system strength,” Reynolds said. “With two synchronous condensers, we’re confident this project can be seen as a trailblazing template for the future of renewables in Australia and beyond.”

For Edify Energy, achieving registration of the project was a particularly big milestone and its first NSW-based solar project. The list of operational solar farms that the Australian developer manages and partly owns includes Daydream (180 MW), Hayman (60 MW), Whitsunday (69 MW), Hamilton (69 MW) and Gannawarra (60 MW) – which was impacted by the WMZ curtailment. All of its projects have deployed an AI-backed trading platform to help navigate the increasing price volatility and maximize returns in the NEM.

“Seeing [the Darlington project] export energy to power NSW homes and businesses is very pleasing. This follows many years of hard work by the Edify team developing, financing, overseeing construction of, and now asset managing the largest operating solar farm in the country,” Edify Energy’s Chief Executive, John Cole, said.

Once again, collaboration was key. “We would like to acknowledge the AEMO and TransGrid teams who worked tirelessly in a very challenging environment with the project team,” Cole said. “The power system is yet to reach peak complexity. We are here to navigate those complexities and develop and deliver new clean energy power stations that are attractive to investors and provide affordable, reliable and sustainable electricity for Australians.”

Much of it can be done with the help of energy storage. According to Edify Energy’s earlier statement, the Darlington Point project will integrate a 100 MWh battery at a later date. This will be the second big battery in the company’s portfolio. Together with Germany’s Wirsol, Edify owns Australia’s largest battery retrofitted to a solar farm – the 25 MW / 50 MWh Tesla battery collocated with the Gannawarra Solar Farm in Victoria.

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