Wind and solar met 100 per cent of more local demand in South Australia’s main grid on all but two days in October, certainly a new record for a gigawatt scale grid worldwide.
The average share of wind and solar energy during October was 72 percent, making some nonsense of claims – with joy repeated by anti-renewal ideologues and pro-nuclear activists – that no grid could support more than 50 percent of the variable renewable production.
South Australia is living proof that it can. It has it over the past year the average more than 62 percent wind and sun, and lifting in October is seasonal, thanks to good winds, good sun and mild weather leading to moderate demand.
The state Liberal government aims to have an average of 100 percent wind and solar energy by 2030, and will most likely reach this benchmark much earlier, thanks to a new transmission link to NSW, the recent removal of many restrictions on wind and solar farms , and the introduction of new storage and smart software.
In October, South Australia mostly reached periods of 100 percent renewable energy through a combination of wind and solar.
However, Solar managed to deliver more than 100 percent alone at various times in several days. Wind often supplied more than 100 percent of local demand overnight and early in the morning.
According to energy data analyst Geoff Eldridge from NEMLog, the highest average share of renewable energy for a full day was 99 percent on October 4, and the lowest daily average for renewable energy for the month was 49.5 percent on October 17.
“The maximum production of renewable energy was 129 percent of local demand on Sunday, October 3,” says Eldridge. The maximum share of renewable energy for an entire day was 107.3% on Sunday, April 4, 2020. “It’s a remarkable transition,” he says.
As the state government has pointed out, the shift to more renewable energy is accompanied by lower emissions, lower prices and improved reliability. It boasts that since 2018 South Australia is the only state that has not experienced a shortage of supplies.
The state’s three major batteries – at Hornsdale, Lake Bonney and Dalrymple North – play a crucial role.
Although they are ridiculed for not being able to supply a large state or large energy user for more than a few minutes (in fact, none of them are large enough to do so in a single second), they play a crucial role in maintaining lattice stability.
They do this by a very fast response to frequency fluctuations, which can give other slower moving machines time to react without compromising supply.
South Australia is a leader in the rollout of battery inverters that can provide synthetic inertia and act as “virtual synchronous machines”.
It has also installed four synchronous capacitors that eliminate the need to have gas generators that provide system power and that also allow wind and solar parks to operate with fewer constraints. These synchronizations are expected to be replaced at some point by battery inverter technology.
Giles Parkinson is the founder and editor of Renew Economy, and is also the founder of One Step Off The Grid and the founder / editor of the EV-focused The Driven. Giles has been a journalist for 40 years and is a former business and deputy editor of the Australian Financial Review.