Recent research analyzed the emissions intensity of the Australian National Electricity Market (NEM) to understand how energy storage can accelerate decarbonisation. The study calculated the Marginal Emissions Factor (MEF) for each time period, representing the emissions intensity of the highest bid price generator.
The average MEF for different NEM regions was found to vary, with some intervals having zero MEF. Intra-day variability showed higher MEF values overnight and during low demand, while low MEF values occurred during peak demand. Interestingly, a strong anti-correlation was observed between MEF and spot price, indicating the need for energy storage optimization to balance costs and emissions.
Understanding the Marginal Emissions Factor (MEF):
The cornerstone of the study lies in the Marginal Emissions Factor (MEF) analysis. The MEF represents the emissions intensity of the marginal generator, which is the generator with the highest bid price, during each 5-minute interval in the NEM. The research examined data from the year 2018 across five NEM regions – SA, NSW, VIC, QLD, and TAS – and calculated the average MEF for each region. The results revealed fascinating insights into the emissions intensity of electricity generation in the grid.
- Average MEF for 2018:
- SA: 0.572 tCO2e/MWh
- NSW: 0.625 tCO2e/MWh
- VIC: 0.567 tCO2e/MWh
- QLD: 0.677 tCO2e/MWh
- TAS: 0.229 tCO2e/MWh
Intra-day Variability and Anti-correlation with Spot Price:
The research highlighted significant intra-day variability in the MEF, suggesting that energy storage operation should focus on fine-tuning its activities within shorter time intervals. Interestingly, during daylight hours, the MEF demonstrated a strong negative correlation with the spot price of electricity in the least cost dispatch market. This means that energy storage optimized for cost reduction might inadvertently hinder short-term emissions reduction efforts. The findings underscored the importance of adopting multi-objective optimization, prioritizing both cost and emissions reductions for effective energy storage operation.
The Path to Rapid Decarbonization:
As the world marches towards a greener future, the research offers insights into the path to rapid decarbonization in Australia’s electricity grid. With increasing penetration of renewable energy technologies and energy storage solutions, the dominance of traditional coal-powered generation is challenged. A comparison between regions like QLD and TAS revealed a significant decrease in the percentage of black coal plants acting as marginal generators during times of low demand and lower market prices.
Energy Storage: The Game Changer:
Energy storage technologies, such as Battery Energy Storage (BES), emerged as the game-changers in this dynamic landscape. With their ability to charge off excess solar generation during the day and discharge during times of peak demand, BES solutions can compete effectively with coal plants that have low short-run marginal costs. As renewable energy technologies continue to advance, energy storage will step up to meet overnight demand, pushing fossil fuel-powered generators to the margins and driving them towards early decommissioning.
Policy and Regulatory Imperatives:
To fully unleash the potential of energy storage in Australia’s clean energy revolution, strategic policy and regulatory interventions are imperative. The research findings emphasize the need for dynamic carbon incentives and market tariffs to align energy storage operations with periods of low emissions intensity. By fostering an enabling environment for energy storage, policymakers can accelerate the transition to a greener grid and achieve the nation’s ambitious decarbonization targets.
Conclusion:
The research into the Marginal Emissions Factor and energy storage has brought hope and inspiration to Australia’s clean energy future. Armed with data-driven insights, we can now harness the transformative power of energy storage to pave the way for a sustainable, low-carbon future.
Paper Title: Emissions and prices are anti-correlated in Australia: what this means for the decarbonisation of our grid
Authors: Louise Bardwell, Lachlan Blackhall and Marnie Shaw; The Australian National University Canberra, Australia
The full paper is under the Creative Commons License CC BY 4.0 and is available here.