Unstable polar vortex conditions and persistent high-pressure systems led to a season of weather extremes across Australia in July and August, resulting in both record-breaking cold and heat. These dynamic weather patterns brought mixed impacts on solar irradiance, with significant variations between different regions, according to analysis using the Solcast API.
July was a challenging month for solar across most of Australia’s National Energy Market (NEM), as much of the population, concentrated on the east coast, experienced cloudier than usual conditions. This resulted in all but two states – Tasmania and South Australia – having lower normalised behind-the-meter PV generation than is typical for July. Western Australia recorded less generation as most of its installed capacity is concentrated around Perth, which saw below average irradiance. Meanwhile, almost all areas in Queensland reported lower than average irradiance, with reductions of up to 10% in some regions.
In contrast, the western half of Australia enjoyed higher than average irradiance, marking a clear east-west divide. The disparity is due to a near record high-pressure system off the coast of Tasmania, which brought record breaking cold to southeastern Australia at the beginning of the month. This cold spell was soon followed by a series of rain bands that further reduced irradiance across much of the NEM.
August presented a more mixed result due to varying weather patterns across the country. Queensland, New South Wales, Tasmania and parts of Western Australia experienced increased cloud cover and rainfall, which dampened solar irradiance. However, the month ended with an extraordinary spike in temperatures, setting new winter records of over 40 degrees celsius in many areas. This was driven by a high-pressure system over eastern Australia and the Tasman Sea, which cleared skies and brought warmer northerly winds. Despite this late surge in temperatures and clearer skies, the earlier wet weather on the East Coast meant that overall irradiance remained subdued.
Victoria and the Northern Territory had a change in fortune, recording greater PV generation than the average August, joining South Australia as the only states to see a boost. Meanwhile, Tasmania saw its lowest normalised generation in the last decade with the whole state experiencing lower irradiance.
The pattern of above average rainfall is expected to persist into the latter part of the year. The Australian Bureau of Meteorology is forecasting higher chances of rain for most of central and eastern Australia, which could continue to affect solar irradiance in these regions.
Solcast produces these figures by tracking clouds and aerosols at 1-2km resolution globally, using satellite data and proprietary AI/ML algorithms. This data is used to drive irradiance models, enabling Solcast to calculate irradiance at high resolution, with typical bias of less than 2%, and also cloud-tracking forecasts. This data is used by more than 300 companies managing over 150GW of solar assets globally.
The views and opinions expressed in this article are the author’s own, and do not necessarily reflect those held by pv magazine.
This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: editors@pv-magazine.com.
By submitting this form you agree to pv magazine using your data for the purposes of publishing your comment.
Your personal data will only be disclosed or otherwise transmitted to third parties for the purposes of spam filtering or if this is necessary for technical maintenance of the website. Any other transfer to third parties will not take place unless this is justified on the basis of applicable data protection regulations or if pv magazine is legally obliged to do so.
You may revoke this consent at any time with effect for the future, in which case your personal data will be deleted immediately. Otherwise, your data will be deleted if pv magazine has processed your request or the purpose of data storage is fulfilled.
Further information on data privacy can be found in our Data Protection Policy.