Australia has two wholesale electricity markets. The National Electricity Market (NEM) covers New South Wales, Victoria, South Australia, Queensland and Tasmania, and clears a spot price every five minutes through AEMO's dispatch process. The Wholesale Electricity Market (WEM) covers Western Australia and uses 30-minute trading intervals.

Spot prices respond to supply, demand and transmission constraints in real time. NEM prices can spike above $17,500 per MWh in extreme conditions, and drop below zero when surplus renewable generation outstrips demand. WEM prices are bounded at roughly $324 per MWh due to the lower price cap.

See more: regional price pages, price forecasts, real-time carbon intensity, wholesale market guide.