Analysis of Historical Spot Prices for the Australian National Energy Market, Growing Concerns about Negative Prices & Postulations on Energy Storage

The National Energy Market (NEM) for Australia has evolved since its birth in 1998. Major milestones have been the introduction of Tasmania in 2005 to the NEM, the introduction of the Clean Energy Act 2011 in 2012 and its repeal in 2014. While these milestones are important and visually striking, there is a growing trend of negative wholesale prices for electricity, both in isolated regional events, or simultaneously across all regions of the NEM. The steady penetration of rooftop intermittent solar and other distributed energy generation systems is noticeably influencing market pricing. Australian Energy Market Operator (AEMO) data is used to visualise this, and postulations are drawn about the possibility for storing energy in battery technologies for environmental and economic gains without needing any price forecasting methods. Open data from AEMO is used to show this.