Five big solar farms in Victoria and NSW have been allowed to resume full supply of power after the electricity market operator and an equipment supplier managed to resolve grid stability issues.
The plants, four of which are in western Victoria and the other near Broken, had been restricted since last September to supplying only half their full capacity of more then 350 megawatts because of congestion on the local grid.
A week of tests overseen by the Australian Energy Market Operator (AEMO) and SMA Australia monitored the performance both individually and as a group of the five solar farms. Engineers used a technical fix to inverters at the plants to smooth power supplies.
“It went well – all generators are very pleased with the outcome,” said Scott Partlin, an executive with SMA Australia. The company supplied inverters – which modulate voltage – to all five farms.
Mr Partlin said collaboration was key to resolving the issue and could prove to be a useful template for fixing such matters if they arise again in the future.
A spokeswoman for the Clean Energy Investor Group, which represents the five solar farms, welcomed the lifting of the so-called curtailment on the plants. Some media had put the revenue loss at as much as $1 million a day.
“Once the curtailed generator issues are resolved, we understand the commissioning and connection of other affected generators in the Western Murray Zone will commence,” the spokeswoman said.
“This process needs to include sufficient information sharing and be well project-managed to give investors the ability to mitigate further risks arising from continuing delays to committed projects.”
AEMO said the lifting of the generation constraints on the five solar farms in the West Murray Zone was “provisional”.
The operater said “unprecedented transparency and collaboration” across the energy sector helped solve the issue of solar farms producing voltage oscillations following a transmission fault, exceeding regulated power system limits.
“The scale and pace of inverter-based solar and wind generation connected in remote and electrically weak areas of the National Electricity Market, like the West Murray Zone, is presenting unprecedented grid performance and stability issues,” AEMO’s Chief System Design and Engineering Officer, Alex Wonhas, said.
“Solving the emergent challenge facing these solar farms required a collective response from many parties to develop a new solution that reduces the likelihood of enforcing constraints on inverter-based generators in areas of low system strength.”