Solar peaks at more than 20% of demand six days in row in mid-winter

It’s getting harder to keep up with all the milestones that are being set as the huge investment in renewable energy over the last few years takes effect on the main grids in Australia, and overseas.

On Monday we noted the remarkable appearance of a zero price for wholesale electricity in all five state markets at the same time. It occurred in the 1.15pm dispatch period in Queensland, NSW, South Australia, Victoria and Tasmania, which together make up the National Electricity Market.

We noted that at the time, the combination of rooftop solar and utility scale solar was more than 22 per cent of total demand. What we didn’t know at the time was that this was part of a series of five consecutive days when solar peaked at more than 20 per cent of total demand – in the middle of winter.

That milestone was noted by Simon Holmes à Court from the Climate and Energy College, who posted this graph taken from the OpenNem resource that they have put together.

Holmes à Court noted that solar peaked at 25.5 per cent of demand on Saturday and renewables – including wind and hydro peaked at 44.6 per cent of demand on Sunday.

Because we only picked this up Monday evening, we waited to see if there would be a sixth day on Tuesday, July 23, and sure enough there is – the combination of rooftop solar and utility-scale solar reached 20 per cent at 11am (Sydney time).

The best performing solar states have been Queensland and South Australia, which have both been regularly peaking at more than 30 per cent solar share over the past week. Even Victoria got to 20 per cent on one occasion, while the best NSW has been able to do is around 19 per cent.

Will this get repeated in summer? Well, there will certainly be more solar output, but demand is likely to be greater too. The periods to watch will be in spring and autumn, on days with little cloud cover and mild temperatures.

Another energy expert, Windlab’s David Osmond, noted more records falling – with wind and solar generation in the main grid reaching 660GWh in one week and then beating that with more than 700GWh over the last week.

Osmond recently noted another unusual milestone, reflecting the growing amount of utility-scale solar in the main grid. According to Osmond, the output of utility scale solar hit an Australian record of 1,752MW on June 22 – the day of the winter solstice!

And expect those records to continue falling – if not on the winter solstice again – as the at least 4GW of currently committed wind and solar projects gradually get completed and go through full commissioning over the next 12-18 months.