The guiding principle for our research is that decentralized energy supply systems should be located near local consumers. One big, local market for energy from biogas plants in Hajdú-Bihar county is Debrecen. In the course of the investigation of biomass suitable for biogas production in the area of Debrecen, this study determines the quantity of biogas producible from animal manure. Municipalities around Debrecen were examined in circles with 40, 20 and 5 km radius. Livestock data of these settlements stem from the Agricultural Census in year 2000, actualized by the county trend of livestock changes. Manure quantity and biogas potential in these places are estimated with coefficients from the literature and our calculations. In the largest circle, about 1.4 million tons of manure is produced, from which round 94 million m³ biogas can be produced. Biomass produced in the settlements and producible biogas shows a remarkable trend of concentration, which supports our recommendation on the system of energy supply.