Instability attributed to changes in power mix that can leave grid at mercy of the weather.
The Australian Energy Market Commission says the national electricity grid is becoming more unstable, with 11 incidents in 2016-17, up from seven the year before and four the year before that.
The instability is attributed to changes in the power generation mix, with thermal, synchronous generators leaving the system in favour of more renewable capacity, which can leave the grid at the mercy of the weather.
The new assessment from the AEMC released on Tuesday comes as the Turnbull government’s prospects of securing agreement for its national energy guarantee have improved courtesy of Jay Weatherill’s departure as the South Australian premier after Saturday’s state election.
Weatherill led the resistance at the state level to the Turnbull proposal, which is supposed to address some of the problems in Australia’s electricity network by imposing new reliability and emissions reduction guarantees on energy retailers and large energy users from 2020.
The Energy Security Board is currently leading consultations with a range of stakeholders about the design of the policy, which will be considered next by federal and state energy ministers on 20 April.
While the Turnbull government has proposed the national energy guarantee as a mechanism to end the decade-long climate wars, the proposal remains contentious with stakeholders, including environment groups and analysts who argue it won’t deliver the scale of emissions reductions to ensure Australia conforms with our commitments under the Paris agreement.
New modelling from market analysts Reputex released on Monday also suggests the Turnbull government’s emissions reduction target for the electricity sector will be met thanks to state renewable energy targets – effectively rendering the federal proposal redundant in climate terms.
The AEMC has meanwhile released new reports taking stock of the reliability of the electricity system. It says system security issues have arisen as a consequence of less synchronous generation in the system and changes in the way generating units are being operated.
It says there has been a reduction in primary frequency control and associated degradation of the frequency distribution – which has implications across the grid.
The report notes that “over the last few years there has been a decreasing level of system inertia due to the withdrawal of synchronous thermal generation and increased penetration of non-synchronous generation” – a development that can “result in the failure of load or generation”.
The report says there were 11 incidents in 2016-17, including the statewide power blackout in South Australia.
It says the frequency operating standard was met for the mainland over the course of the year but the frequency operating standard was not met for Tasmania for seven months of the 2016/17 financial year.