Isometric has certified a module for Biomass Storage in Subsurface Mines (BSSM). This module sets out requirements and procedures for storing sustainably sourced waste biomass in existing subsurface mines and is designed to be used alongside the Subsurface Biomass Carbon Removal and Storage Protocol.
Certification follows a comprehensive public consultation that included feedback from buyers, suppliers, and leading academics. Full details on the evolution of the module and how Isometric addressed feedback from the consultation are available in the changelog and public consultation summary.
Under typical conditions, waste biomass—such as cotton stalks or sawdust—decomposes over time, releasing the carbon dioxide it captured during photosynthesis back into the atmosphere. This decomposition can be slowed or even halted by removing or reducing the factors that enable it—such as oxygen or moisture—locking away the carbon contained in the biomass.
Subsurface mine chambers provide a promising solution for durably storing waste biomass. Their depth maintains stable temperatures naturally, and their enclosed design allows for the creation of low-oxygen conditions needed to slow or halt decomposition. Additionally, the use of existing chambers avoids the need to build completely new infrastructure.
This module is designed for subsurface mines that are currently in operation as well as those that have closed or are closing. The robust storage and monitoring requirements included in the BSSM Module will enable the issuance of carbon removal certificates with a durability of over 1,000 years.
Carbon removal supplier Rewind provided extensive feedback during the development of the module. Rewind aims to generate carbon removal certificates from its Deep Mine Storage Georgia project using the BSSM module.
Ram Amar, Co-Founder and CEO of Rewind, said:
“Rewind focuses on science-led, permanent, and energy-efficient carbon removal. Our biomass storage projects in disused mines combine the carbon capture efficiency of plants with the scale and permanence of existing underground voids.
“Being science-led brought us to work with Isometric. It's been a pleasure to support the development of this new module and we look forward to applying it to our DMS Georgia project."
The module was developed in line with the Isometric Standard, through collaboration between Isometric’s in-house Science Team and reviewers from Isometric’s independent Science Network of more than 400 academic experts and practitioners.
