Politicians, primary stakeholders and local community groups gathered for the event. 

The plant is a milestone for renewable energy in Australia. 

"Developing two solar plants of the magnitude of Nyngan at 102 MW and Broken Hill at 53MW is a major accomplishment and signals the birth of large-scale solar in Australia," AGL Managing Director and CEO Andy Vesey said.

Together, the sites host more than two million solar panels and all now feed power into the national electricity grid. 

Australian Renewable Energy Agency acting CEO, Ian Kay said the opening of the farms was the result of hardwork and commitment over many years.

"In the future, this historic achievement will mark the moment big solar started to become a major contributor to Australia's energy supply," he said. 

Both the Nyngan plant and the Broken Hill plant have generated over 200,000 MWh of renewable energy which is enough to power around 34,000 average Australian homes. 

Jack Curtis, Asia Pacific manager for First Solar, AGL Energy's partner was delighted by the technology developed through the construction phase of the two plants.

Mr Curtis announced at the opening the company had set up a low-cost local supply chain for key equipment which would drive down the costs of future projects. 

"First Solar has successfully established a low-cost local Australian supply chain for key equipment driving down the cost of delivery of future Australian solar projects," he said. 

"As ageing coal power plants are decommissioned, there is an enormous potential for renewable energy, and utility scale PV in particular, to fill the void and provide clean and affordable electricity."