WASTE HEAT FROM BIOGAS PLANTS: EXPERIENCES FROM 10 FEASIBILITY STUDIES IN GERMANY

Many biogas plants aim to maximise the electrical output from biogas in combined heat and power (CHP) units, due to supportive policies that mainly focus on electricity production (feed-in tariffs). As a result, in many cases the heat from CHP units is only partly used, or wasted. This inefficiency in energy use is a bottleneck in current biogas production, causing macroeconomic and microeconomic losses and challenges in the context of overall increasing land use competition. This has a negative impact on the public perception on biogas. In the framework of the BiogasHeat project 10 feasibility studies for existing biogas plants in southern Germany were elaborated. Heat data were collected from the biogas plants and interviews were made. This paper gives an overview on the use of waste heat from biogas plants in Europe and Germany. It presents and compares the outcome of the studies in Germany.