Rooftop solar takes even bigger bite out of coal market as grid demand slumps to record low

Rooftop solar has increased its seemingly unstoppable incursion into the market for fossil fuelled power, sending operational demand on Australia’s main grid down to another low amid clear skies and a mild weekend.

The new low of 12,583MW reached at 12.30pm on Sunday was nearly three per cent lower than the previous minimum set almost a year ago in October, 2021, according to the Australian Energy Market Operator.

At the time, AEMO said, rooftop solar contributed 42 per cent of total energy demand. According to other data suppliers, such as GPE Nemlog2, grid demand also fell to record lows in the two biggest state grids, NSW and Queensland.

Operational demand is important for the market operator, because as demand falls it reduces the amount of traditional tools it has at its disposal to match supply and demand.

In some states such as South Australia, operational demand is likely to head towards zero as the share of rooftop solar surges towards brief moments of supplying the equivalent of 100 per cent of state demand.

To deal with those events, the market operator is looking at a variety of measures such as “dynamic” controls over rooftop solar, increased storage, demand management and more transmission links.