Firming 100% renewable power: Costs and opportunities in Australia's National Electricity Market

Abstract

The decreasing cost of solar photovoltaic (PV) and wind power technologies makes 100% renewable energy systems economically viable. Building more capacity to mitigate periods of low solar and wind supply results in systems that produce surplus energy at other times. As these surpluses vary across time and space, it becomes crucial to map their geographic distribution and quantify their magnitude. This paper presents the largest geographic and longest time series analysis of oversizing solar PV and wind in the context of the Australian National Electricity Market. We examine the additional solar, wind and battery capacity required to meet 100% of demand between 2010 and 2020. Without battery storage, this is achieved by generating approximately four times demand at an average production cost 28% lower than recent wholesale electricity prices. The addition of 1–8 h of storage reduces the average production cost by 55% compared to recent prices. Our analysis also investigates the spatiotemporal characteristics of surplus energy generation under different scenarios. We identify which regions are most suitable for the expansion of industrial, commercial, and business operations using surplus renewable generation.