The electricity mix of Brazil is for 80% composed by renewable sources, of which the majority is supplied by hydropower. However, as the domestic energy demand is expected to increase and the abilities to expand hydropower capacity in Brazil are constrained, it is important to increase the contribution of other renewable energy resources. Considering the high theoretical potential and mature conversion technologies, bioelectricity from sugarcane straw could be a promising option. Our study aims to assess the bioelectricity potential from ecologically available sugarcane straw in the state of Sao Paulo (Brazil) at multiple scales for the 2012 crop-year. We use a spatially explicit approach taking into account the spatial distribution of sugarcane fields, the spatial variation of sugarcane yield, the location and the milling data of each mill. We define a business as usual, a moderate and a high scenario on the amount of straw that can be removed given environmental constraints. The bioelectricity potential from ecologically available sugarcane straw is estimated between 18.7 and 45.8 TWh in Sao Paulo, equal to 22-37% of the electricity demand. The results show large geographical differences, with generally higher potentials and shorter collection radiuses for the mills in the traditional sugarcane areas compared to the mills in the expansion areas. We conclude that bioelectricity from sugarcane straw could have a significant contribution to the electricity supply in Brazil. The identification of regions with high potentials for bioelectricity production could support local and regional decision making on bioenergy planning.