Agricultural waste and especially straw can provide a significant share of biomass energy. However, due to the very nature of agricultural production, as well as a need for carbon sequestration in soils and other aspects of food production, only part of the straw potential may be treated as waste and spent on energy production. Based on statistical data from the Polish Central Statistical Office (CSU) the actual production of straw was modelled on a scale of local districts (NUTS-5) as well as the needs of its local use and the possibility of redistribution of excessive quantities to regions with a deficit of straw. As a result, the straw surplus that could be used in the energy sector was obtained along with its geographical distribution. Next, a cost-minimising transport model is used to optimise the straw's allocation among main power plants all over the country, taking into account capacities and technical constraints of co-firing biomass with coal. The results are detailed at the municipal level indicating excess capacity for biomass co-firing by plant and regions to be satisfied by additional biomass sources such as biomass from forest or energy plantations. (C) 2013 Elsevier Ltd. All rights reserved.