Two Victorian power stations have been forced to cut generation after a problem with coal supply from an adjoining mine.
The Australian Energy Market Operator notified the market late on Sunday that coal reliability supply issues from the Loy Yang brown coal mine forced AGL’s Loy Yang A and Alinta’s Loy Yang B power stations - which both take coal from the mine - to reduce generation by around 1400 megawatts across both power stations, or the entire generation capacity of Loy Yang B, as well as one of the generation units of Loy Yang A.
"AEMO was informed by a power station operator of short-term reliability issues," an AEMO spokeswoman said.
"AEMO continues to closely monitor the situation, however, there are no reliability or security issues at present."
An AGL spokesman confirmed the generation reduction was due to issues with coal supply.
"This was from a combination of planned maintenance on mine equipment and unforeseen circumstances," the AGL spokesman told Fairfax Media.
"The maintenance interruption briefly affected coal supply to, and generation at, Loy Yang A power station but there was no lack of reserve or threat to system security."
A source familiar with the situation said the process was mostly maintenance and they were surprised by AEMO releasing a market notification as previously maintenance downtimes did not warrant notifications.
“This isn’t an unusual thing to happen, but it is unusual that AEMO would put a notice out,” he told Fairfax Media.
He said in cases like these many market watchers assume that any generation unit downtimes are breakdowns or could lead to a blackout, but it was simply maintenance processes at the mine itself, adding that this time was chosen as it was typically a period of lowered demand.
Alinta, the operator of the Loy Yang B power station, was unavailable for comment at the time of publishing.
Maintenance at the Loy Yang coal mine took around six hours and reduced generation from 8 pm on Sunday night until 6 am Monday morning when it began returning to full capacity.
It comes only days after the Yallourn power station suffered a series of small fires after coal dust combusted.
An EnergyAustralia spokesman said two small fires broke out on earlier this month.
“The source was ignited coal dust in the hot and dry weather,” the spokesman told Fairfax Media.
Fires of this nature can be long in duration and hard work to extinguish.”
This fire also marked four years to the day when similar fires broke out at the now-closed Hazelwood power station’s brown coal mine, which ran rampant for 45 days and covered the region in toxic smoke.