Cold start to spring sees Australians use 30% more gas than last year – even though the price was up too

It comes as renewable sources powered 39.3% on average, the Aemo says, a record share for the September quarter

Greenhouse gas emissions from Australia’s main electricity grid increased for a third quarter in a row as higher power demand drove more use of black coal and gas plants, the Australian Energy Market Operator says.

For the September quarter alone, emissions from the national electricity market (Nem) that serves the eastern states and South Australia rose 2% from a year earlier, Aemo said in its quarterly market report.

renewable sources reached 39.3% on average, a record share for the September quarterThe increase of 700,000 tonnes of carbon dioxide equivalent lifted the tally to 28.4MtCO2-e, adding to a 2MtCO2-e increase in the June quarter and a marginal rise in the previous three months.

Output from gas plants averaged 1,493 megawatts for the quarter, up 29% from a year earlier even though prices for the fossil fuel increased by a fifth. Black coal-fired power stations lifted by 1.8% to average just under 10,000MW, while brown coal plants averaged 0.7% less output to 3,703MW.

The cold start to the quarter also helped lift electricity demand by 3.4% from the September quarter of 2023. Increased supply from rooftop solar – up 11% from a year ago – helped trim the rise in so-called operational demand from the grid to 2.6%.

The share of power supplied by renewable sources reached 39.3% on average, a record share for the September quarter. Wind generation increased just over a fifth to average 4,044MW, also a record high, offsetting a similar-sized decline from hydro generation as dam operators conserved water amid sliding capacity levels.

The result of increased use of pricey fossil fuels lifted wholesale electricity prices compared with the same quarter of 2023, a trend already identified by the Australian Energy Regulator earlier this month. By Aemo’s slightly different measure, wholesale power prices averaged $119/MW-hour, or 88% more than for the same period last year.

That increase may contribute to higher retail prices next financial year when contracts are updated. Wholesale power prices make up about a third of households’ electricity prices although government rebates – particularly state ones – have provided big reductions in what many people pay, according to the latest inflation data.

The Aemo report, though, also pointed to an increase in new renewables making their way from application to commissioning. About 45.6 gigawatts of clean energy capacity is in that pipeline, up 36% from a year ago, it said.

Battery projects alone amounted to 14.6GW, or 87% more than for September quarter last years.

“It is promising to see Australia’s energy transition continue with more renewable generation capacity either coming online or progressing,” Violette Mouchaileh, an Aemo executive, said in a statement.

Mouchaileh noted that for a half-hour period during the middle of the day on 9 September, renewables supplied a record 72.2% of the Nem generation. More than half of that came from rooftop solar.

Renewables potential – the amount of energy available but not necessarily reaching users – also touched an all-time high of 100.5% for a half hour on 18 September.

However, so-called “economic offloading” – when the grid had to curb output – reduced the share of generation coming from solar farms.

Grid-scale solar plants faced an additional 41MW of curtailment. That contributed to a 68MW reduction, or 4.5%, in average output from solar farms to 1,461MW during the quarter, Aemo said. Their share of total generation eased to 5.9% of Nem supply, down from 6.4% in the September quarter of 2023.