Biomass residues from rubber trees in rubber producing countries have immense potential for power production. This paper presents the case of the south peninsular of Thailand, where the rubber industry is intense. Mathematical models were developed to determine the maximum affordable fuel cost and optimum capacity of the power plant for a given location of known area-based fuel availability density. GIS data of rubber growing was used to locate the appropriate sites and sizes of the power plants. Along 700 km of the highway network in the region, it was found that 8 power plants are financially feasible. The total capacity is 186.5 MWe. The fuel procurement area is in the range of less than 35 km. (C) 2003 Elsevier Ltd. All rights reserved.