Why is spring the record-smashing season for Australian renewables?
Australia’s main electricity grid (the NEM) has set a flurry of new records for renewable energy penetration since the start of spring.
For extended periods in September and early October, almost three-quarters of electricity demand was being met by wind, solar and hydroelectricity.
The AEMO reported a new instantaneous peak in renewable energy market share for the NEM – which spans Queensland, New South Wales, Victoria, Tasmania, South Australia and the ACT.
At its peak, the market share of renewables hit 73.7%.
It is not just peaks that are setting new highs; renewables met more than 45% of the NEM’s demand in September – itself a new record for a full month.
AEMO says its goal is to co-design and co-engineer the NEM and the WEM to manage 100% instantaneous penetration of renewables at any moment on any day by 2025.
So why is spring the season for record renewable penetration?
Solar irradiation increases dramatically the closer we get to summer. In Chinchilla, Queensland – home to the state’s largest solar farm – irradiance doubles over the spring, and output increases correspondingly.
A more subtle factor is that the industry is busy adding more solar panels to the system through autumn and winter, installing panels on homes and building new utility-scale projects.
But while spring marks sunnier days, the season also benefits from the milder temperatures that help to keep the overall demand for electricity low.
The production of renewable electricity is highest in the summer, but average demand also soars thanks to air conditioning.
Spring sits in a renewables sweet spot; increasing solar production, higher than average wind production (but only slightly) and milder temperatures that help suppress electricity demand and push out coal and gas.