Potential contribution of biogas to net zero energy systems – A comparative study of Canada and Germany

Urgent action is needed to stay within the Paris Agreement's temperature goal of limiting global average temperature rise to 1.5 Celsius above the pre-industrial levels. Very stringent emissions reduction and accelerated transition from fossil fuel-based to low- or zero-carbon systems is key, together with additional atmospheric carbon removal to control remaining anthropogenic CO 2 levels. Biogas, derived from organic residues and waste, can not only provide a valuable sustainable substitute for natural gas, but also serve as a tool for carbon dioxide removal, e.g. when combined with CO2-separation during upgrading to biomethane, or through usage of digestate (including biochar). Moreover, as a mature technology, it provides a significant near-term opportunity for bioenergy with carbon capture and storage. This study assesses the potential contribution of biogas made from biogenic residues and waste to net-zero energy systems. Our comparative analysis includes a biomass potential assessment, a review of current biogas production practices, and an examination of CO 2 flows along the biogas value chain. We present a consolidated and harmonized dataset for Germany and Canada, identifying a significant potential to contribute to CO 2 emission reductions, with an estimated 30 million tons per year in each country. The contrast between the two countries is informative. In Germany, the provision of biogas and biomethane is already widely established, whereas Canadian biogas usage is still at an early stage in certain provinces. Canada, however, has a stronger focus on CO 2 separation, and more coherent options for carbon capture and storage. To unlock their full potential, each of the two countries' distinct strategies could draw on the other country's complementary experience in deriving an optimal solution. • Biogas provision can contribute to carbon dioxide removal in different ways. • Germany and Canada have reasonable biogenic residue streams for biogas production. • Both countries could capture up to 30 million tons CO2 per year with biogas. • Between the countries, different implementation strategies are necessary.