The Western Australia grid has recorded its highest ever level of variable renewable energy penetration, after the state’s rooftop solar and large scale solar and wind generators combined to supply 51 per cent of underlying system demand in November of 2019.
The Australian Energy Market Operator said in its Quarterly Energy Dynamics report for Q4, 2019, that the new milestone was achieved for that state’s grid – or WEM – at 11.30am on November 30.
“At the time, 51 per cent of underlying system demand was supplied by VRE output,” the report notes. “This was a result of mild temperatures, clear skies (resulting in high rooftop PV output) and high wind speeds.”
The new record comes as the state grid, which is separate to the National Electricity Market, and operates as an island, with no connections to any other grid, grew the generating capacity of rooftop solar and wind by an average 87MW and 63MW, respectively.
The 47 per cent increase in wind generation capacity was largely attributed to the connection of the 130MW Badgingarra wind farm at the beginning of 2019 and the 9.9MW Beros Road wind farm in Q3, AEMO said.
Rooftop PV’s growth contributed to a maximum quarterly output of 994MW, and – as reported on RenewEconomy last year – at one point on September 29 supplied as much as 45 per cent of the state’s underlying system demand all on its own.
The NEM – which encompasses South Australia, Tasmania, Victoria, the ACT, New South Wales and Queensland – itself passed the 50 per cent benchmark for renewable energy in November of last year, when the combined output of rooftop PV and big wind and solar reached 50.2 per cent of supply on the main grid.
The report also highlighted the changing dynamics of the grid, with AEMO recording the lowest ever operational demand of 1,159MW on Sunday, October 13, driven by low demand and high rooftop solar output.
Over that same weekend, the W.A. also experienced its lowest ever prices, with wholesale electricity price cleared at the Minimum STEM (short term energy market) price of minus $1,000/MWh for what is known locally as the balancing market.
This occurred during three trading intervals over the weekend that weekend, thanks in part to the lowest operational demand and by the strong output of rooftop solar which averaged 927MW over those three trading periods.