A summer of record renewables, record demand highs and record demand lows, and no blackouts

Australia’s main grid has just finished a summer of records – record demand highs across the grid, record demand lows, and record average renewables of 44.7 per cent.

More importantly, even as wind, solar and hydro power edges towards half of all generation needs, there were also no supply shortfalls – despite growing problems with the reliability of the ageing fossil fuel fleet and the sometimes hysterical blackout predictions of the Coalition and some far right think tanks and media.

And consumers can largely thank the growing impact of battery storage for that grid reliability and absence of blackouts – apart, of course, from those caused by storms and other factors that might have torn down local power lines – and their ability to respond quickly to demand and supply needs, and their flexibility.

The last summer played witness to the first directions to big batteries to be on standby in the event that minimum demand fell to levels where it would make the grid difficult to manage.

It also saw big batteries, including the new massive Waratah Super battery that was being put through its commissioning, playing a critical role by charging up to be on standby in the event of a potential supply shortfall in the midst of a heat wave.

In Western Australia, an isolated grid that cannot rely on electricity imports and exports with other states, new big batteries at Collie and Kwinana also played a critical role absorbing excess output from rooftop solar in the middle of the day and re-injecting that power into the grid in the evening demand peaks.

Source: OpenNEM

The 44.7 per cent share of renewables is the highest for summer, although it is shaded by the 46 per cent share in the spring that preceded it. Spring is usually the season of such records, because demand is lower as a result of the milder temperatures.

According to Australian Energy Market Operator data provided to Renew Economy, the 44.7 per cent share compares to a renewables share of just 24.1 per cent five years ago in the summer of 2019/20. In the summer of 2023/24, the renewables share was 40.3 per cent.

AEMO chief executive Daniel Westerman says the solid reliability outcome is the result of sustained collaboration with the industry.

• “Over the past few months, our control room operators and industry partners navigated significant generation unavailability, record-breaking peak demand, and low-demand challenges,” he said in a statement.

“We continue to invest in connecting new generation and storage projects, which are critical for reliability and security in the face of increasing demand and retiring coal power stations.”

Australia is aiming for a renewables share of 82 per cent by 2030, part of a planned transition that will likely see the last of the country’s coal fired generators retired within a decade.

But that will depend on the pace and scale of new wind, solar and storage capacity, and the build out of new grid infrastructure, including transmission lines. And that, in turn, will also largely depend on the result of the federal election due to be held within the next two months, and which polls suggest remains on a knife-edge.

AEMO will provide further data once its own four-month summer season – which goes to the end of March – is complete, but it notes that there were several other key milestones, including record operating demand in the W.A. grid of 4,486 MW on January 20, and record operating demand in Queensland on January 22 of 11,144 MW.

On the other side of the scale, NSW recorded a minimum operating demand record of 2,728 MW on February 16, while AEMO declared an “actual minimum system load” level 1 in Victoria on both December 22 and January 1 because so much demand was being eaten up rooftop solar.

The MSL calls require batteries to be put on standby, near empty, in case they are needed to charge up and create more demand to allow AEMO to keep enough utility-scale generation on line to control the grid and respond to any fluctuations.

Geoff Eldridge, from GPE NEMLog, says another interesting aspect of the summer was the curtailment of wind and solar, which reached eight per cent over the summer – with Victoria and South Australia the worst affected because of negative prices – and was largely due to the insufficient transmission links and insufficient storage.

Eldridge also notes that hydro played a key peaking role. “With a peak share of 11.2%, hydro ramped up in the evenings, complementing coal and gas in balancing the grid,” he wrote on LinkedIn.

According to Eldridge, wind and solar (the state has no hydro) provided an average 74.6 per cent of native demand in South Australia over summer. South Australia is the country’s – and the world’s – most advanced renewable grid in terms of the integration of solar and wind. It has a target to reach an average net 100 per cent wind and solar in 2027.

Over the past summer, its numbers for wind and solar would have been higherwere it not for the need for curtailment, which reached 10 per cent in the state over the summer period.

“During solar hours (9am to 5pm), South Australia could have met 100% of its native demand (includes behind the meter rooftop PV) with renewables, with surplus available for export – if not curtailed,” Eldridge wrote on LinkedIn.

“Yet variability remains a challenge, requiring firming, storage, and interconnection support. Renewables can dominate, but flexibility is essential.”

Victoria had the lowest daily average price at $56/MWh (South Australia was at $66/MWh) over summer – almost half that of the coal dependent Queensland ($108/MWh) and NSW ($103/MWh), highlighting the north-side divide between state with more renewables and those with more baseload coal.

“Storage and demand flexibility must scale to absorb excess midday renewables and reduce reliance on coal for evening peaks,” Eldridge notes.

“Hydro and batteries are critical to managing evening ramp-ups as fossil fuel generation declines. Interconnectors and market reforms could improve price stability and energy utilisation, preventing price extremes.”

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