Australia’s biggest solar farm registered, with two big spinning machines

The 275MW Darlington Point solar farm – the biggest solar farm to be built in Australia so far – has finally completed the generator registration process and will now begin to send power to the grid, and to its biggest customer, the owner of a major coal generator in NSW.

The announcement came in a joint statement from the project owners, Edify Energy and UK-based Octopus Investments, and the Australian Energy Market Operator, which is now publicly celebrating new connections in what is a problem part of the network.

Darlington Point – despite being located in what it says is an “ideal” part of the grid, near Griffith in south-west NSW – has installed two synchronous condensers –  large rotating machines that mimic the operations of coal or gas generators, to try and ensure that it is not penalised for any grid stability issues that may emerge.

However, Darlington Point is one of a number of operating and soon-to-be-commissioned wind and solar projects that have been warned of “material” constraints or cutbacks to their output because of concerns by network owner Transgrid of congestion in the area, and the risk that too much power might be sent back at certain times towards Wagga Wagga.

Darlington Point – which was originally due to begin production earlier this year – is also located in an area of the grid known as the West Murray zone, which is considered weak, and where “system strength” have been identified, and where five big solar farms had their output cut in half for more than seven months because of potential voltage issues.

Project developers in the region have been warned of extended delays to the congestions and commissioning, and AEMO has recently decided that projects will be connected one by one (sequenced), so that grid issues can be monitored.

In the statement, AEMO’s Chief System Design & Engineering Officer, Alex Wonhas, said that the Darlington Point solar farm’s registration is another important milestone towards unlocking new generation in the West Murray Zone.

“AEMO congratulates Edify Energy and Octopus Investments in achieving registration for the Darlington Point Solar Farm,” he said. “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.”

The head of Octopus Investments in Australia, Sam Reynolds, said solar farms of this scale – it the company’s first big investment in Australia – 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.

Ironically, one of the solar farm’s biggest customers is Delta Electricity, the owner of the Vales Point coal generator, which has contracted to take 150MW of the capacity until 2030. Vales Point is due to retire at that time.

“AEMO’s latest Integrated System Plan aligns with our ambitions – to finance the urgently needed expansion of renewable energy in Australia,” Reynolds said.

“This comes with the challenge of ensuring the new generation can operate reliably on the power grid and maintain system strength. 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.”

It is thought that AEMO has largely solved – at least on an interim basis – the so-called system strength issues in the West Murray Zone (which are different to congestion problems).

This solution was likely based on contracts with syncons, such as those installed at Darlington Point, or at other solar farms such as Kiamal and Finley. But no details have been released.

And Transgrid has said that syncons – while good for system strength, will not solve the newly identified congestion issues. Syncons have been around for half a century, and provide a rotating mass that does not burn fuel. The hope is that these can be replaced by smarter, and cheaper, “grid forming” inverters.

Edify Energy’ CEO John Cole said it was pleasing to see Darlington Point reach its registration. (One nearby solar farm, Sunraysia, has been unable to do this, despite being mechanically complete for nearly a year).

“Achieving registration of the Darlington Point Solar Farm and seeing it export energy to power NSW homes and businesses is very pleasing,” Cole said.

“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.

“We would like to acknowledge the AEMO and TransGrid teams who worked tirelessly in a very challenging environment with the project team. 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.”