Beyond wind: furthering development of clean energy in South Australia

Abstract

The deep and rapid decarbonisation of electricity supply systems is an essential component of mitigating the impacts of climate change. Despite a high penetration of wind-generated electricity (27%), South Australia remains connected to, and reliant on, one of the most coal-intensive electricity grids in the world – Australia’s National Electricity Market. Here we explore the changes to South Australia’s electricity generation in the context of the recent, large expansion of wind-generated electricity, the impacts of this expansion, and the potential for alternative, low-emissions technologies to help the State complete the decarbonisation task. We find that although the expansion of the wind-generation sector in South Australia has delivered meaningful reductions in greenhouse-gas emissions in just over 10 years, the limitations of strongly correlated and variable electricity supply that is decoupled from electricity demand place upper limits on the plausible future contribution from wind. System costs arise from integrating these sources, both from managing uncorrelated supply and the declining availability of ancillary services such as the frequency control provided by synchronous generators. These costs have been minimal to date, largely due to the connection to the National Electricity Market and already available, open-cycle gas turbines as reserve margins. However, evidence of large-scale integration costs is emerging and expected to increase should wind continue to grow in penetration. Development of the South Australian hot dry-rock geothermal resource has confirmed the well-documented challenges in developing this energy source, with still no operating power supply after more than 30 years of development. Solar–thermal technology remains uneconomic in the absence of either substantial subsidies or high carbon pricing. Given these inherent constraints, the deployment of nuclear energy technology provides the pathway of greatest technical and economic certainty for the permanent displacement of fossil-fuelled baseload electricity generation in South Australia. Nuclear power is, however, hampered by legislative barriers and requirements for the development of legal and regulatory frameworks. Support for the nuclear option is broadening within South Australia, and innovative economic development strategies based on the deployment of generation IV ‘integral fast reactors’ could spur the necessary bi-partisan political support to transition the State’s electricity supply entirely to low-emissions sources.