Characteristics and availability of biomass waste streams and residues for power production by means of integrated gasification/combined cycle technology (BIG/CC), are evaluated for The Netherlands. Four main categories are investigated: streams from agriculture; organic waste; wood; and sludges. Altogether 18 different streams are distinguished. Gross availability and net availability are inventorized. Various properties (composition, heating value, supply patterns) are analysed and the suitability of these streams for conversion in a BIG/CC unit is studied. The costs at which various streams are likely to be available are assessed. The gross energetic availability amounts annually to approximately 190 PJ (HHV) primary energy. Because of competing useful and higher value applications than fuel of various streams, such as fodder and fertilizer, the net availability is slightly less than 90 PJ (HHV). For a number of streams the costs are negative due to present waste-treatment costs. Costs of waste streams vary from — 10-5 ECU/GJ. For a small fraction the costs are higher than for energy crops (estimated to be approximately 4.5 ECU/GJ). Because there are large variations in properties and contaminants between various streams, the conversion system needs to flexible when a diversity of streams is treated in one installation. Some streams require mixing with cleaner fuels to make them suitable for use in a direct atmospheric biomass integrated gasifier/combined cycle system. Important technical limits for the use of biomass fuels in the system studied, are the moisture content (maximum 70% of wet fuel) and ash content (maximum 20% dry matter content) of the fuel.