The methanization process is at the crossroads of several issues: energy through biomass treatment, waste management through by-product recovery, climate through the reduction of greenhouse gases, and agriculture through diversification and supplementing agricultural income. However, the spread of methanization faces obstacles in France. It seems important to consider the factors of success or failure related to biogas projects. A quantitative study (logit model used on 91 anaerobic digestion projects) and a qualitative study (49 semi-structured interviews) were carried out to identify and understand the processes that anaerobic digestion projects went through to succeed, or conversely, to fail. Our findings show that the abandonment or stopping of a project is strongly related to the presence of a group of objectors, who are often wary of these projects and do not trust the project leaders. Furthermore, social acceptance seems to be correlated to proximity to biogas plants. We conclude by identifying operating and/or investment subsidies as having a positive and significant effect on the success of these projects.