Unplanned outages hit capacity
Almost one-fifth of Perth and the South West's electricity generating capacity was forced offline this week because of unplanned outages, forcing expensive diesel-burning peaking generators to be used.
Major coal generators owned by Synergy at Muja and Kwinana power stations were unavailable because of faults at the same time as gas turbines at Pinjar were switched off as a precaution because of a nearby bushfire.
The outages represented about one-third of the government-owned utility's generating portfolio and sparked questions in the energy market about the cause.
"Ordinarily, an outage situation of this scale would be caused by a gas crisis," an energy market participant said in an email to the Independent Market Operator. At the peak of the outage, which lasted from late Tuesday until Thursday lunch time, between 909MW and 1107MW of generation capacity was offline.
Last night, 670MW was offline, with Pinjar back up after the fire, but the Muja and Kwinana units were still unavailable.
The South West interconnected system has about 5800MW capacity, including about 500MW of so-called demand-side management, where big power users voluntarily disconnect from the network in last-resort situations.
"Synergy has experienced some untimely issues with a number of its generation units this week, which was also exacerbated by our decision to withdraw generation units from service on a precautionary basis due to the risk of bushfires in some areas," Synergy general manager generation Barry Ford said.
"Muja 6 has been offline since the end of November 2014 due to the failure of a transformer and is not expected to be returned to service until next month.
"Muja 8 had a drain line pipe failure this week and is expected to be online early next week. (It) coincided with a similar issue on Kwinana 6, however, that unit is also expected to be available, if required, early next week."
