Analysis of selected economic and environmental impacts of long distance manure transports to biogas plants

In regions with high livestock density, manure supply often exceeds demand and complete local deployment would lead to severe environmental damage due to over-nutrification. One solution is to use the surplus in other regions, which have lower nutrient-levels. To decrease costs associated with transport the manure can first be used in biogas plants of those regions. To date, however, the economic and ecological consequences of this solution are unclear. Here, we develop a model of the consequences from the perspective of a biogas plant owner and apply it to a case study in Lower-Saxony, Germany. The model determines the maximal profitable manure transport distance from a financial point of view. Furthermore, it examines selected environmental impacts for various scenarios with an assumed transport range of 150 km, a typical distance. For dry poultry manure transport distances up to 700 km and more can be financially advantageous. Emission reductions occurred in all scenarios in the impact categories Greenhouse Gas and Acidification. The model can support decision-makers in the livestock and biogas industries in determining whether to transport manure and, if so, how far.