This represents the third Callide power generating unit restored to operational generating status since the May fire and explosion, which triggered a highly disruptive unscheduled plant shutdown.
The recovery of the C3 unit follows progress made last month, where the B1 and B2 units were restored after a month of hibernation allowing for critical repairs and upgrades.
Energy minister Mick de Brenni said the C3 unit went back online in the early hours of today.
"This milestone brings capacity up to almost 75%…[the] entire Callide team have displayed an unwavering focus on returning the units safely and have worked methodically through the return to service process," de Brenni said.
"As C3 is safely and gradually ramped up to full capacity, we can expect Callide to start generating up to 1,120 megawatts of reliable energy into the National Electricity Market."
CS Energy, which owns and operate Callide in a 50-50 joint venture with InterGen Australia, reiterated the final unit won't return to service until the end of next year.
CS Energy CEO Andrew Bills says an external investigation into the C4 unit is still underway.
"Lead investigator Dr Sean Brady and his team have been onsite at Callide Power Station...to undertake a comprehensive investigation," Bills said.
"CS Energy is committed to understanding the facts that led to the C4 event so we can learn from it and improve the safety of our people and plant."
