Contractual obligations and grid security trump counterparty economics. You have traders taking/offloading risk. I'm not familiar with this micro-market, but

Contractual obligations and grid security trump counterparty economics. You have traders taking/offloading risk. I'm not familiar with this micro-market, but power prices go negative in the US frequently where tax incentives make it profitable to operate renewables plants at prices < -$20/MWh.