The palm oil mills are characterized by the availability of considerable amounts of by-products of high-energy value such as empty fruit bunches (EFB), fibers, shells and liquid effluents with high content of organics called palm oil mill effluent (POME). A palm oil mill produces residues equivalent to almost three times the amount of oil produced by biomass, showing a huge potential for increasing the power efficiency of the plants and installed power, mainly by the use of by-products in cogeneration plants with high steam parameters and by reducing steam consumption in process. The objective of this paper is to present the results of the study about the cogeneration potential for three representative palm oil mills located in two important palm oil producing regions in Colombia (South-America), fifth palm oil producers of the world. The sizing of the cogeneration system was made assuming it operation during the greatest possible number of hours throughout the year (based on the seasonal availability of fruit) considering parameters for the steam at 2 MPa and 350 degrees C, using a condensing-extraction turbine. The balance of mass and energy was made by using the Gate Cycle Enter Software, version 5.51, to estimate the potential of electricity generation. The results showed that for fresh fruit bunch (FFB) processing capacities between 18 and 60 t FFB h(-1), it is possible to have surplus power ranging between 1 and 7 MW, if the plants are self-sufficient in electric energy and steam for process. With an average Capacity Factor (approximately 0.4), it is possible to expect a generation index of 75 and 160 kWh t(-1) FFB when the processing plant is operating or shutdown, respectively, 3 or 4 times better than when a traditional system with a back-pressure steam turbines is used. This analysis used up to 60% of EFB produced in plant as fuel, considering its value as fertilizer for the palm crop. Several economic conditions were considered to estimate the economic and technical feasibility of cogeneration systems in palm oil mill for Colombian palm oil sector. (C) 2007 Elsevier Ltd. All rights reserved.