Recent restructuring of Brazil's power sector, allied to the expected larger share of natural gas in the nation's grid and the cost reductions of gas-fired power generation technologies, has introduced a set of situations apparently favorable to the expansion of natural gas-fired cogeneration. However, electricity self-generation applications are restricted to specific cases in Brazil. In order to deal with this issue, the COGEN model was developed to assess the economic potential of cogeneration ventures from the standpoint of the investor and guide incentive public policies. This model has been applied to two cases in Brazil - a chemical plant and a shopping mall -showing that the highest economic potential for gas-fired cogeneration in Brazil is found in industrial plants faced with high values of loss of load. In the commercial sector, measures reshaping the load curve of enterprises - such as cold storage - might be much more interesting than fired cogeneration.