Achieving 100% Renewable Energy in Australia: The Role of Back-Up Technologies

What is it about?

This study presents a model of Australia's National Electricity Market (NEM) designed to determine the optimal mix of firming technologies for a system largely powered by variable renewable energy (VRE) sources like wind and solar. The study evaluates the effectiveness of three firming technologies: pumped hydro, batteries, and 'zero emission' open-cycle gas turbines (OCGTs), particularly under 'energy drought' conditions where solar and wind resources are scarce. The findings suggest that despite potential high costs, OCGTs using green fuels such as hydrogen or biodiesel are necessary to ensure reliability during these periods due to the limited storage capacity of batteries and pumped hydro. The study emphasizes the importance of a diverse mix of firming technologies to maintain an affordable and reliable electricity system, highlighting that a range of technologies with varying costs can reduce average operational expenses by 10-20%. Furthermore, the study suggests policy implications, noting that adjustments in market settings, such as increasing the NEM's Cumulative Price Threshold, may be needed to encourage investment in long-duration firming solutions.

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Photo by Ian on Unsplash

Photo by Ian on Unsplash

Why is it important?

This study investigates the transition of Australia's National Electricity Market (NEM) towards 100% renewable energy sources, focusing on the challenges and solutions related to energy resource adequacy. The broader relevance of this research lies in its examination of how to maintain energy reliability and security during periods of low solar and wind resource availability, known as 'energy droughts.' The findings have significant implications for energy policy, particularly in relation to the integration of firming technologies and green fuels to support renewable energy systems. Key Takeaways: 1. The research demonstrates that while pumped hydro and battery storage can address short-term mismatches in energy supply and demand, they may not be sufficient to manage prolonged 'energy droughts.' As a result, fuel-based technologies, such as those utilizing hydrogen, will likely be necessary to ensure energy reliability. 2. Findings reveal that a combination of different firming technologies, including pumped hydro, batteries, and 'zero-emission' open-cycle gas turbines, can reduce the cost of serving load duration curves by 10-20%, highlighting the importance of a diverse technology mix to achieve cost-effective energy solutions. 3. The study suggests that policy adjustments are needed to support the transition to a renewable energy system, including modifications to market settings like the NEM's Cumulative Price Threshold. This would incentivize long-duration firming technologies and support infrastructure development for zero-emissions fuels.