New regulatory changes could significantly increase the amount of methane emissions reported by coal mines, as well as make methane recovery and utilisation a more attractive option, according to a new UQ Gas & Energy Transition Research Centre (UQGET) study.
The study, which was jointly written by a team from UQGET and Novus Fuels, examines a range of Bowen Basin coal mines using the new, more precise methane emission estimation methods that will soon be adopted by Australia’s Safeguard Mechanism. Using representative gas content data from those operations, the researchers conclude coal mines could see their reported methane emissions increase by upwards of 3.6 - 4.2 times.
The Australian Government's Safeguard Mechanism is designed to reduce industrial greenhouse gas emissions, including fugitive methane that is unintentionally released during mining operations. Mitigating methane emissions is seen as particularly critical due to the fact methane traps 28 times more heat in the atmosphere than carbon dioxide.
Study co-author Professor Ray Johnson said the more accurate estimation methods may result in higher compliance costs for miners.
“Until now, coal mine methane emissions have been reported using Method 1, which estimates emissions based on the tonnage of coal produced rather than direct measurements,” Professor Johnson said.
“However, starting in 2025, open-cut coal mines must adopt more precise estimation methods (Method 2 or 3). These mine-specific geological models will provide a more accurate picture of methane release, which could result in reported emissions quadrupling at some operations.
“This transition will likely increase compliance costs for miners, who must reduce emissions or purchase carbon credits to offset excess methane under the Safeguard Mechanism.
“However, it also creates opportunities for the industry to implement cost-effective mitigation strategies and rethink how CMM can be utilised rather than wasted.
“In the study, we find that pre-drainage strategies can reduce methane emissions by 38%, while pre-drainage combined with subterranean barriers could achieve a 46% reduction.”
Opportunities for methane recovery and utilisation
Professor Johnson added that the regulatory change presents an opportunity to harness previously, through processes such as gas drainage and utilisation, to help alleviate supply constraints.
"Methane from coal mining has long been difficult to capture and use because of its dispersed and low-rate nature,” Professor Johnson said.
"However, if emissions are significantly higher than previously estimated, the scale of gas recovery opportunities may be greater than anticipated, creating new avenues for beneficial use and emissions mitigation.
“An obstacle to this is that the current regulatory framework discourages industry from investing in large-scale methane capture and utilisation, as the Safeguard Mechanism primarily targets short-term emissions reductions without encouraging medium- and long-term strategies.
“Policymakers should consider mechanisms that reward early investments in emissions reduction projects with long-term benefits.
“By recognising coal mine methane as a viable energy resource, industry and regulators can shift from a compliance-only mindset to an approach that leverages emissions reductions as an opportunity.
“Improving incentive structures for methane recovery and ensuring efficient regulatory implementation will be critical in making the most of this newly recognised resource.”
UQGET continues to research reservoir and decarbonisation technology with expertise in subsurface development and emissions management, contributing to Australia’s transition to a more sustainable energy system.
For more information about this research, contact Professor Ray Johnson at r.johnsonjr@uq.edu.au.
