We need grid ready for 100 pct renewables now, not in a few decades: AEMO

AEMO chief systems design office Alex Wonhas says the country’s main grid is rapidly approaching 100 per cent instantaneous renewable penetration, and it needs to build a system and market that can handle such situations now, not in a few decades.

“The current registration rate is 27 per cent higher than what the ISP ‘Step Change’ scenario requires, which ‘only’ has 2.6 GW p.a. capacity additions,” Wonhas says.

“AEMO has visibility of 75GW of new generation across 343 potential projects, which is 15 per cent more than what Step Change requires.” And, he warned, existing generators are more likely to exit the market faster than currently announced.

The next version of the ISP, due mid 2022, is likely to outline scenarios that include an even faster transition to renewables, possibly 100 per cent, or close to, by the mid 2030s, driven by both technology advances and the accelerating global push to address climate change and limit global warming to 1.5°C.

“The size of variable renewable energy (wind and solar) ramps is growing,” Wonhas said in his speech notes.

He said the largest hourly downward VRE ramp in the NEM was 1.4GW, historically, but this was expected to grow to around 4.5GW by 2025. “Diversity is important,” he said.

The solution to these challenges would come from the priorities identified by the Energy Security Board, including resource adequacy; essential system services; demand side participation; and access and transmission reform.

Wonhas also pointed to the need for controllability and fault ride through of distributed energy resources such as rooftop solar, the creation of renewable energy zones, the existence of adequate dispatchable generation and demand side solutions, DER, and frequency, voltage, system strength  resources “ideally with 21st century technology” – which means inverters and not old thermal plant.

“This will set us up well for the next wave of changes,” he said, which would include the rapid uptake of electric vehicles, increased electrification that would lead to a doubling in the size of the grid, and a transition to a (green) hydrogen export economy.