South Australia’s incredible week: 104.1 per cent wind and solar over seven days

South Australia aims to reach 100 per cent “net renewables” within a few years – over a full year – but in the past week it has already done better than that.

Our attention to the state was sparked by a tweet from Teal supporter and energy analyst Simon Holmes a Court, who tweeted on Friday that the state had average an “incredible” 99.8 per cent over the previous seven days.

When we checked before writing this story on Sunday afternoon, it had done better than that – averaging 104.1 per cent over the seven days (to 2.30pm AEST on Sunday).

To be clear, this 104.1 per cent relates to the amount of wind and solar compared to state demand. The state is connected to the rest of the grid so imports and exports are inevitable, so the figure is already a “net result.”

But it is still impressive. There was no coal and gas provided just a little over six per cent of demand over the week. Imports accounted for just 2.6 per cent and exports of wind and solar for 13.7 per cent of total production.

The state is benefiting from new wind and solar joining the grid and the roll out of synchronous condensers that are cutting back the amount of gas needed for system security.

Two new batteries – at Blyth and Bungama – will be built in the state to provide many of those services going forward, and the construction of a new link to NSW may reduce the need for fossil fuels for grid security down to zero.

Holmes a Court also noted that over the last three days, the share of renewables has been even higher – 105.6 per cent, when the average price has been minus $24 a megawatt hour.

When we looked, it was even higher again – at 107.9 per cent. Over the last week, the average price has been minus $28/MWh.

That means that some wind and solar farms will have been switched off during that time, and most owners are contracted so are guaranteed to receive a fixed power price.

Meanwhile, the Australian Energy Market Operator has confirmed that the Western Australia main grid, which is not connected to another system, reached an instantaneous record of 84.3 per cent last Monday.

It noted that between 8am to 3pm local time, renewables supplied an average 78 per cent of underlying demand. Most of this came from rooftop solar.