Analysis of Negative Electricity Price to Identify Demand Management Opportunity for Consumers in Renewable-rich Power Systems

• Main Authors: Chen, William, Gath, Bradley, Kinross-Smith, Emily, Toole, Hamish, Yusofi, Eid, Hasan, Kazi N.
• Format: Conference Proceeding
• Language: English
• Subjects: Asia; Australian NEM; Data analysis; demand management; Electricity supply industry; Generators; Nanoelectromechanical systems; negative electricity price; Pricing; Renewable energy sources; renewable-rich grids
• ISSN: 2378-8542
• DOI: 10.1109/ISGTAsia49270.2021.9715625

Since the maximum renewable generation and peak demand do not occur simultaneously, in renewable-rich power systems, it is required to either store/curtail excess renewable generation(s) or to ramp up/down conventional generation(s). In these cases, to avoid the intermittent shutdown of large generators, generators bid at negative electricity prices, which may bring the market clearing price to negative. In such a scenario, large electricity consumers may employ a demand management strategy by managing their loads to capture the market benefits. This research explores the recent emergence of negative electricity pricing, particularly in the Australian NEM. It collects electricity load, price, and solar PV generation data from the Australian NEM, for all 5 states during 2016-2020, in half-hourly intervals. The data analysis has identified 6886 negative price events during this period with an average value of -46.63 /MWh and a minimum value of -919.78 /MWh. The detailed analysis recommends that the negative pricing is (1) progressively becoming more common, (2) increasing with the increased penetration of renewables, (3) happening more in the summer season when PV penetration is high, (4) likely to increase on weekends and off-peak periods, and (5) common in the middle of the day when the PV penetration is high.