This article presents a comparison of the economic, environmental, and energy performance of two 75 kW gas-fired and diesel-fired power plants. A series of performance tests have been conducted to register emission values at different operation points for both technologies. Additionally, a simulation model has been developed to evaluate the performance of both technologies under different operating scenarios based on the assumption that the plant will operate as a backup to a local distribution system. Initially, the model has been provided with theoretical information collected from different bibliographic sources. Subsequently, the model input data have been replaced from the results obtained in the measurement process. Finally, the results and the main conclusions identified during the development of the project are presented.