Solar pushes Qld network peak into evening in G20 heat

Here is an interesting graph that showed what happened with the electricity load in south east Queensland at the height of the heatwave that hit Brisbane and surrounds during the final day of the G20 meeting.

Being a Sunday, there was not a lot of commercial and industrial load, but the residential load was heavy as households fired up the air-conditioning. (Queensland has more than 90 per cent penetration of air-con, and about 25 per cent penetration of rooftop solar).

This graph is remarkable because it shows what nearly 900MW of rooftop solar capacity on the Energex network in south-east Queensland does to the peak – instead of being around 4pm it is pushed to 7pm. Both the height and the length of the peak is changed. South Australia, the other state with as much solar, has also recorded similar changes, much to the approval of the grid operator.

That has changed the equation for those generators that used to rely on big peaks – and very high prices – to provide a big slice of their annual revenue (some 25 per cent in just 36 hours of peak power according to some calculations).

But it also highlights the challenge to the grid. Solar detracts from energy consumed, and while it is succeeding in delaying the absolute peak, it is not removing it. Once it can do that – presumably with the assistance of battery storage installed by either the household or the grid operator – then the equation will change dramatically, and servicing the peaks will no longer be the massive cost burden that it has in the past, and still is.