The current operating requirements in South Australia mandate around 80MW of gas generation for system strength reasons.
So even on last Saturday when "operational demand" in South Australia reached the ballpark of -200MW (that is, rooftop solar generation was exceeding the demand in the state by 200MW), there was still 80MW of gas in the mix. (The excess was being exported to Victoria).
So even on last Saturday when "operational demand" in South Australia reached the ballpark of -200MW (that is, rooftop solar generation was exceeding the demand in the state by 200MW), there was still 80MW of gas in the mix. (The excess was being exported to Victoria).