A few interesting points about the NEM that help explain why it's avoided a simple situation.

1: There are multiple price caps that set a maximum price on energy. 2: There's a commonly traded instrument that effectively acts as an insurance product for retailers against high prices. This means peaking generators get paid every quarter, even if they plants don't run at all. 3: The Australian government is spending billions building pumped hydro and gas generators to ensure supply over and above what the private sector is willing to fund.