New research reveals that some energy-from-waste (EfW) facilities emit more carbon per unit of electricity than coal-fired power stations, despite being promoted as a cleaner alternative to landfills.
The study, published in Nature Energy, highlights the growing impact of plastic content in waste streams and stalled improvements in energy conversion efficiency as key contributors to the problem.
Monash University researchers analysed nearly 600 EfW plants across China over two decades, where rapid urbanisation has driven EfW capacity to process 700,000 tons of waste daily by 2020.
While these facilities have reduced landfill emissions, their environmental performance varies widely based on waste composition and technology.
In regions with high plastic content and outdated infrastructure, EfW plants struggle to achieve efficiency, emitting more greenhouse gases than conventional coal power.
The study identifies rising plastic content in waste as a critical factor inflating emissions.
“In areas with high levels of plastic waste and older technology, EfW plants can be less efficient and produce higher emissions,” said Dr Jenny Zhou of Monash’s Nature, Urban and Human Lab.
China’s EfW expansion — now the world’s largest — faces dual challenges: insufficient waste segregation and lagging energy conversion rates compared to standard power plants.
Co-author Ben Liu, a PhD candidate in Civil and Environmental Engineering, emphasised that improved recycling and modern equipment could mitigate these issues.
“A key trend in China’s waste is the rising plastic content, leading to increasing carbon emissions from EfW,” Liu said, adding that Australia’s more advanced waste classification practices position it to adopt higher-efficiency EfW systems.
The research outlines a roadmap to halve EfW emissions by 2060, aligning them closer to natural gas’s emissions profile.
Recommendations include enhanced waste sorting, investment in high-efficiency modules, and integrating carbon capture and storage (CCUS) technologies.
Professor Victor Chang, Deputy Head of Monash’s Civil and Environmental Engineering Department, stressed that EfW’s sustainability depends on balancing waste management with clean energy goals.
“Without careful planning, cities risk substituting one high-emission source for another,” he warned.
In Australia, projects like Western Australia’s Kwinana and East Rockingham EfW plants aim to reduce landfill reliance.
Liu noted that Australia’s waste has a higher heating value than China’s, offering potential for optimised EfW systems if paired with advanced technology.
The findings underscore a global challenge: as nations adopt EfW to manage waste and generate energy, plastic pollution and technological stagnation threaten its climate benefits.
The study calls for international collaboration on waste segregation policies and innovation in EfW infrastructure to ensure the sector supports — rather than undermines — decarbonisation efforts.
“Energy-from-waste has great promise, but its future hinges on systemic improvements in how we manage waste and modernise these facilities,” Dr Zhou concluded.
