Limondale solar farm registered in West Murray

Following the successful resolution of the West Murray system strength saga, the Australian Energy Market Operator (AEMO) is getting on with the pipeline of projects waiting to be connected in that part of the grid. In “a major step forward”, AEMO has granted registration for the RWE Renewables-owned 220 MW Limondale Solar Farm, located near Balranald in south-west New South Wales.

In April, AEMO lifted the generation constraints on five solar farms totaling more than 350 MW in the West Murray Zone, region straddling the state borders of Victoria and NSW. The Bannerton, Broken Hill, Gannawarra, Karadoc, and Wemen solar farms were radically curtailed to half of their output for seven months after it was determined that their combined operations were a source of uncontrollable voltage oscillations triggered by normal disturbances to the grid – such as lightning strikes.

The solution to the network issue in the region involved tuning the solar farms’ inverters to operate in concert, rather than individually when delivering clean energy to the grid. With no new physical components or hardware changes used to engineer the solution, the inverter supplier to all five generators, Germany’s SMA, developed a new inverter capability to address a “live” problem on the grid. Implementing the solution was a mammoth effort joint effort between AEMO, generators, the inverter manufacturer, networks and consultants, highlighting the importance of collaboration in the energy transition.

Major milestone

After the curtailment was imposed, all other connection work in the region came to a complete halt. For months, some 45 other solar and wind projects in the region were sitting idle. However, the successful implementation of the new solution to voltage oscillations allowed AEMO to progress assessments of new generation projects in the West Murray Zone.

AEMO is aiming to have all committed projects in the West Murray Zone connected by early 2021, where possible. A major milestone towards unlocking new generation in the region was announced on Thursday following the registration of one of the biggest solar farms in the region. Once again, collaboration was key.

“AEMO congratulates RWE Renewable in achieving registration for the Limondale 1 solar PV farm and recognises the company’s collaborative and responsive approach through the connection process to registration,” said AEMO’s Chief System Design and Engineering Officer, Alex Wonhas. “While the West Murray Zones presents very challenging network conditions, the collective efforts from across the industry and TransGrid in working with AEMO is helping address these emergent grid performance and stability issues,” he said.

Once fully commissioned, the Limondale solar farm will be one of the biggest PV plants on Australia’s main grid. The project was supplied by U.S.-based PV maker SunPower with its Chinese-made, 19% P-Series modules and SMA, which installed its 1,500V Medium Voltage Power Stations (MVPS) 5500 units to the project. Construction was completed by Downer Group, which exited the solar sector in February.

The project consists of Limondale 1 and 2, featuring approximately 872,000 panels and an export capacity of 249 MW AC. The second stage of the project, the 29 MW Limondale 2, was the first to reach full production earlier this year. With the registration completed, the bigger chunk of the project can now begin the commissioning process.

RWE Renewables Senior Asset Manager, Peter Veljkovic, also acknowledged the hard work of all parties involved to achieve the registration milestone. “The hard work, collective effort and collaborative approach utilised by AEMO and TransGrid, throughout this process, has been fundamental in achieving registration,” he said. “Limondale Solar Farm thanks all those involved especially the site construction teams and our advisors and suppliers all of which have been crucial in achieving this milestone.”