Economic analysis of the installation of biogas plants in dairy farms : a Finnish case study

Dairy farms account for a large portion of the greenhouse gas emissions in the planet. Since cow manure provides a good medium for anaerobic digestion, this study analyzes the economic feasibility of installing a biogas plant adjacent to a 200-cow farm in Finland. The farms in this study produce only cow manure and grass silage to feed the digester. This paper focuses in comparing different scenarios such as electricity production for farm needs and the production of biofuels such as compressed biomethane as an additional business activity. After designing the farm economic model and the biogas installation, we provide an economic analysis of each scenario. The first one shows that it is not feasible to run the biogas business model based only on electricity savings for the farm. The second one proves that additional revenue streams such as biofuel production can revitalize and strengthen the financial model of the plant. Then, the sensitivity and reliability of the model is discussed by providing reasons (i.e. Finnish electricity tariff system) for the outcome of the results. The model reinforces the idea that farms must base their biogas business model on alternative side-streams and do not rely on energy production only. For further research, it is recommended that real life farm business models are incorporated as input data and a proven plant and CHP engine energy balance is secured