Influential Synoptic Weather Types for a Future Renewable Energy Dependent National Electricity Market

Abstract

This study presents an analysis of the synoptic scale influences on potential renewable energy output for eastern Australia (the National Electricity Market (NEM) region). Common synoptic scale weather patterns are identified using a Self-Organising Map (SOM) of 1989-2009 ERA-Interim Mean Sea-Level Pressure (MSLP) for the Australian region. Using wind speed and surface shortwave radiation output from the Australian Community Climate and Earth-System Simulator (ACCESS) regional model (ACCESS-R) for 2010-2011, in tandem with a Genetic Algorithm, a cost-optimal placement of renewable resources for the NEM is derived. Moments of very low output from the combination of wind and solar are then analysed to show that a ridging high pressure system south of Perth and a summer continental heat low significantly co-occur with very low output. Another MSLP type represented by a cold front approaching South Australia was shown to never associate with very low output. An investigation into the 2010-2011 period when compared to the previous 21 years showed that the La Niña conditions during 2010-2011 period were more challenging than normal for wind and solar for some areas. What the study also shows is that despite the large geographical area the NEM region cannot rely solely on nondispatchable renewable electricity, without installing unrealistic amounts of over-capacity.