Utility scale generation of renewables in Australia creates tradable certificates. These are required by law to be purchased by energy retailers to meet the Ren

Utility scale generation of renewables in Australia creates tradable certificates. These are required by law to be purchased by energy retailers to meet the Renewable Energy Target. If that certificate trades at $50, I can sell my power for -$40 and still make $10 profit. Putting further downwards pressure on prices, small scale solar generators (eg homes) generally have a fixed price for solar exports. The spot price could be -$1000 but they will still be getting paid $100 under their retail contract. So they have no incentive to stop generating, even when the price is negative. The market regulator is attempting to change this, but consumers are resistant to having to pay to generate power or allow their system to be remotely switched off. Coal generators won't switch off either as they take a while to ramp up and down, and are sometimes are directed (and paid) to remain running to provide system stability.