![The energy mix during peak demand hours in New South Wales on Feb 10 [source: AEMO]](http://gastopower.co.uk/media/k2/items/cache/bc5c1834b47f4a16a26da89ea51b0c06_S.jpg)
Failures at gas-fired power plants in New South Wales during a heatwave affecting eastern Australia at the beginning of February contributed to an overload in the electricity system in the state, according to a report of the Australian Energy Market Operator (AEMO).
On February 10, the eastern Australian states of South Australia, New South Wales, Victoria, and Queensland all experienced high summer temperatures, leading to peaks in power demand of 14,181 MW in New South Wales.
However, power supplies were insufficient to meet increased demand, AEMO said.
In particular, some 408 MW of generation capacity were unavailable at EnergyAustralia's Tallawarra power plant, on the back a forced outage of generators due to a fault in the gas turbine; moreover, 600 MW gas-fired units at SnowyHydro's Colongra power plant were unable to start due to low gas pressure in the fuel supply lines, and a number of thermal generators reduced output. In addition, wind and solar photovoltaic generation reduced by around 300 MW between 17.00 and 18.00. All these factors “combined to overload the New South Wales interconnections with Queensland and Victoria, creating an insecure operating state” AEMO said.
With no further generation available to serve the demand and relieve the overloading interconnectors, as a last resort AEMO instructed TransGrid to reduce demand at the 290 MW Tomago aluminium smelter “to restore the power system in New South Wales to a secure operating state,” it added.
AEMO to assess plant capability accuracy
The New South Wales Government had warned on February 9 of potential electricity shortages, advising customers to reduce electricity consumption “where possible.”
AEMO said this may have resulted in demand being approximately 200 MW lower across the peak afternoon period.
Following the peaks in demand in February 10, AEMO has “assessed the adequacy of the provision and response of facilities and services” and “the appropriateness of actions taken to restore or maintain power system security,” finding that generally “all actions and responses of facilities and services were adequate.” Nevertheless, it said it intends to “consider further whether plant capabilities during extreme conditions are accurately reflected in bid and availability information.”