AEMO warns of ‘load shedding’ as grid pushed to breaking point
The Australian Energy Market Operator warned of possible “load shedding” – mandatory power cuts – of up to 40 megawatts in each of Victoria and South Australia late on Thursday.
The warnings are in addition to a large reserve margin gap of more than 700 MW from 11am to 6pm forecast for Victoria during Thursday’s extreme heat and are the most severe for the National Electricity Market since the horror summer of 2016-17.
The sudden trip of another generating unit on Wednesday afternoon escalated the crisis, making four out of action in Victoria and NSW and putting the expected reserve into deficit in Victoria and South Australia on Thursday afternoon.
The forecast LOR3, the first to be declared by the market operator since 2017, means that the Australian Energy Market Operator “will be pulling on additional resources” to plug the gap and keep the grid secure, meaning it will most likely trigger demand response, an AEMO spokeswoman said.
A final decision on triggering the Reliability and Emergency Reserve Trader system or RERT is likely to be made by 8am tomorrow. LOR stands for “lack of reserve”.
The warnings triggered preparations to call in back-up power and demand response to keep the lights on. Reserve generating capacity in Victoria, where temperatures are set to soar past 40 degrees across much of the state, is expected to be down to about 2½ per cent of Thursday’s peak demand, leaving only a thin buffer in the supply system.
Thin buffer for 'nasty day'
“It’s a very very small amount of reserve for a very very nasty day,” Dean Spaccavento, chief executive of Reposit Power, a battery management software company, told The Australian Financial Review.
South Australia, which no longer has any baseload generators, is continuing to swelter in the mid-40s range, while the plant shutdowns have taken about 1000 MW out of the loop across the National Electricity Market, making the situation more serious than last week’s narrowly averted squeezes.
“We’re looking at weather in South Australia that we haven’t seen for 80 years so this is an all-time peak and clearly the system is under a lot of stress in terms of meeting the need,” said Audrey Zibelman, AEMO chief executive.
“We are looking at pulling more resources into the market – that’s exactly why we plan the system as we do to have those reserves available.”
Reposit said that in addition to any customers’ mobilised by AEMO to reduce their demand, thousands of customers of retailers Powershop and Diamond Energy participating in the software firm’s “grid credits” scheme – under which they receive $1 a kilowatt hour for the energy they save or send back to the grid during supply squeezes – will be standing by.
One hopeful note came from South Australia, where good winds are forecast for Thursday afternoon which could help to close the supply gap, Ed McManus, chief executive of Powershop and its owner Meridian Energy Australia, said.
Meridian will also deploy about 30 MW of supply from its Hume Dam hydro generator as needed, and industrial companies such as Australian Paper are also standing by under AEMO’s demand response program.
“This will be a test of Victoria and I think it’s relatively clear now that the kind of pressure on the grid is going to continue, it’s not a flash in the pan,” Mr Spaccavento said. “We need to have a power system that can deal with these things.
A tube leak in the 560 megawatt unit three at Loy Yang A in the Latrobe Valley took that unit offline on Tuesday afternoon, causing AEMO to hike up the expected shortage in reserve capacity available for Victoria on Thursday. The unit is likely to take about three days to repair.
The Loy Yang A problem comes as EnergyAustralia’s 435 MW Tallawarra gas plant at Wollongong is already out of action after an unexpected outage on Thursday, while its Yallourn coal plant in Victoria, which saw a fatal accident in November, is also operating at less than full capacity with essential maintenance being carried out at one unit.