Calculating the carbon intensity of biofuels
6 May 2025
The Bioenergy Association of NZ and EECA engaged Toitū Envirocare to develop a biogas and biomethane greenhouse gas accounting methodology to use as an agreed standard within the emerging renewable gas sector within New Zealand.
GasNZ provided industry input.
This carbon intensity methodology covers the three waste-to-energy processes of wastewater treatment, landfill gas capture, and anaerobic digestion of organic waste to produce biogas and biomethane.
The intended use of the carbon intensity (CI) methodology is to:
Provide a publicly available, standardised GHG accounting methodology for evaluating the CI for biogas and biomethane production and use which meets international best practice;
Provide the key metrics and measurements required for biogas and biomethane products to satisfy the GHG accounting required for renewable energy certification (REC) schemes;
Establish New Zealand sector requirements for measurement, monitoring, and reporting for biogas and biomethane’s carbon footprint.
Internationally biogas which is refined to pipeline standard is often referred to as renewable natural gas (RNG). In New Zealand however, distributed gas is usually referred to as biomethane.
An industry steering committee that included GasNZ members provided oversight and feedback throughout the project.
The Bioenergy Association says the methodology is a living document welcomes ongoing feedback.