Wind drought: Turbine output slashed to 14%

Wind turbines barely generated 14 per cent of Australia’s electricity in the past 12 months, as the nation relied on coal and gas to keep the economy running.

Fossil fuels - coal, gas and liquid - delivered 70 per cent of Australia’s electricity over the past 12 months, as a wind farm turbines came to a standstill.

Wind turbines barely generated 14 per cent of Australia’s electricity in the past 12 months, as the nation relied on coal and gas to keep the economy running.

Analysis of Australian Energy Market Operator data shows fossil fuels – coal, gas and liquid fuel – generated 70 per cent of the nation’s 187 million megawatts delivered to the grid.

Wind generated just 26 million megawatts (13.9 per cent of the total), solar 15.6m MW (8.3 per cent), hydro power 13.8m MW (7.4 per cent) and biomass 0.35m MW.

The slump in wind generation comes despite it sharing in $1.6 billion of large-scale renewable energy certificate subsidies.

Fossil fuels generated 70 per cent of Australia’s electricity over the past 12 months.

AEMO estimates the capacity factor of wind turbines, the amount of time they are generating electricity, slumped from the standard of about 33 per cent down to 25 per cent, as a wind drought hit eastern states in autumn and early winter.

Over the three months to June 30, AEMO reported: “Victoria experienced the lowest quarterly volume-weighted available capacity factor at just 22.9 per cent over this quarter.”

The last time the nation suffered such a severe wind drought was in 2017, which coincided with cooler than average nights and the second-driest June on record.

Last year, University of NSW Centre of Excellence for Climate Extremes researchers published a Nature journal article that found “widespread wind droughts feature anticyclonic conditions (high pressure systems) over eastern Australia during winter, spring and autumn”.

The analysis raises questions over the impact of global warming on wind generation, given numerous studies have found it leads to more high pressure systems sitting over southern Australia for longer.

Research led by the CSIRO and reinforced by 35 climate models shows global warming will strengthen the sub-tropical ridge of high pressure systems and push it further south during winter, delivering stable and dry conditions.

Back in 2015, CSIRO’s Ocean and Atmosphere Flagship team, along with BOM scientists reported the “sub-tropical ridge is projected to strengthen and move pole-ward under global warming, contributing to reduced rainfall in the cool season in southeast Australia”.

During summer the ridge of high pressure sits over southern Australia, preventing any southerly fronts penetrating the region, before heading north in winter.

But in winter the ridge usually migrates north, allowing cold fronts and low pressure systems to move up from the Southern Ocean and bring rainfall to southern Australia.

If the ridge fails to head north, it means southern Australia not only misses out on southerly rainfall, but the winter westerlies.