South Australia goes from an importer to exporter of electricity for the first time, in 2017-18 renewables era

South Australia's monthly electricity via the interconnector to Victoria in 2017 changes from import to export.
Image courtesy Dylan McConnell, University of Melbourne
South Australia became a net electricity exporter for the first time in 2018. A prime factor in this was the closure of the Hazelwood brown coal generator in 2015, cutting 25% of supply in Victoria. Victoria was South Australia’s only link to the national power grid.
But also in the leadup to South Australia’s switch to being a electrictity exporter were 12 new wind and solar farms totalling 1050MW of capacity added to the state's grid, including 500MW of large-scale solar, trebling the amount of large-scale solar in the system.
The continued rapid uptake of rooftop solar by homes and businesses kept a lid on grid demand, while overall consumption rose. This was a big change for South Australia from 1999-2000 when it had only gas and local coal generators and used to import 30% of its electricity demand.
In 2018, nearly half of South Australia’s power came from renewables. Gas-fired generation increased in South Australia as a result of the Northern closure but is still below the levels of a decade ago.
Because gas was expensive, more investment in battery storage was expected. Homes’ rooftop solar was the most steadily growing source in the national electricity market. The new Liberal South Australian government in 2018 said it would continue the transition to renewable energy, driven by the compelling economics of clean energy and will continue the rollout of energy storage in family homes.
The 2018 report by Australian Energy Market Operator (AEMO) warned increased renewables in the system heightened the need for fast-start and rapid-response technologies to smooth out their intermittent nature. It acknowledged that South Australia;s Tesla 100MW battery had helped stabilise the national grid.