Biogas does more than just generate electricity and gas. A new report from IEA Bioenergy Task 37 shows that anaerobic digestion also contributes to climate change, nutrient cycling, clean water, and economic resilience.
IEA Bioenergy counts 53 sustainability impacts
The authors map fifty-three impacts. They organize these along five perspectives that together cover the biogas playing field: waste and wastewater, agriculture and the countryside, the use of digestate and biofertilizers, the use of energy products such as biogas, biomethane, and biogenic carbon dioxide, and the impact on society as a whole. Biogas is known to help reduce greenhouse gases, but other positive effects often remain underexposed because they are difficult to quantify. The rapporteurs cite odor and noise as negative effects that can be mitigated with sound business practices.
Experience from five countries
The report brings together insights from Canada, France, Norway, Sweden, and Switzerland. The technology is similar, but the context differs. Switzerland has broadly integrated biogas into its water cycle, with almost complete coverage at wastewater treatment plants. Canada's methane strategy emphasizes landfill gas capture and treatment. In France, catch crops are often fermented alongside manure. Norway and Sweden digest sludge from fish processing to reduce the risk of eutrophication. All five countries work with standards and guidelines for digestate to ensure nutrients return to the soil and to reduce fertilizer use, while protecting water and soil as a prerequisite.
Broad consideration makes biogas competitive
The study discusses examples where more than just energy and emissions are taken into account. In Sweden, multi-criteria analyses for transport show where biomethane adds the most value. Additional studies from France, Switzerland, and Europe partially express effects in monetary terms. When benefits and avoided costs are included, biogas appears socio-economically competitive compared to both fossil and other renewable options.
Policy determines the outcome
The scope of the effects depends heavily on policy, infrastructure, and the role biogas plays in the energy transition. The authors highlight the risks of a one-sided focus on electrification and future hydrogen systems. They recommend scientifically sound multi-criteria assessments, recognition of the interconnections between waste, water, agriculture, energy, and industry, the removal of unnecessary barriers in regulations and procedures, and clear targets for biogas, biomethane, digestate, and biogenic carbon dioxide, along with access to infrastructure.
More information and link to the report "Identification and assessment of sustainability effects associated with biogas solutions": ieabioenergy.com
Image: Task 37 of the IEA Bioenergy TCP
