Accelerate the World's Transition to Sustainable Energy - to fight Anthropogenic Climate Change, page-36405

Can't ramp up supply to plate capacity on wind or solar..so must be using all the 'cheap' battery power to keep the light son.
Oh look a practical example of economics 101.

Wholesale prices surge as wind and solar output falls to zero in South Australia.

Wholesale electricity prices surged on Monday morning in the southern states after wind and solar output in South Australia – the grid with the highest average share of the technologies – fell to zero soon after 7am.

According to various data sources, including GPE NEMLog2, the output of wind and solar fell to zero at 7.05am, just before rooftop and large scale solar kicked in to the grid. Wind output remained very low throughout the morning.

It is not the first time wind and solar have hit zero – they did so in June last year for a brief moment, according to GPE NEMLog, but the fossil fuel generators and the growing portfolio took full advantage and pushed the wholesale price towards the newly elevated market cap of $17,500 a megawatt hour in the absence of any competition.

Note - building MORE batteries will NOT make power cheaper.