Application of R-curve analysis in evaluating the effect of integrating renewable energies in cogeneration systems

Because of their higher efficiency, cogeneration systems are widely used in many industrial plants. Moreover, due to concerns about environmental issues, replacing conventional fossil fuels with clean and sustainable energy resources seems inevitable. In This paper, the effect of integrating renewable energy resources in cogeneration systems is investigated. As will be demonstrated, integration of these resources can either improve or deteriorate the performance of the cogeneration system. Therefore, R-Curve tool is used for a detailed analysis on the effect of integrating renewable energies on the performance of the cogeneration system. Different scenarios for integration of solar and wind power as well as solar heat are investigated. Also, a new benchmarking index is proposed as a comparison tool for integration of renewables into total site utility systems. Finally, three cases are studied using the proposed concepts. As the results suggest, with the same renewable system, there is a considerable difference between savings for different scenarios of integration. Accordingly, as an example, integration of a 13 MW solar power plant can be associated with either 53 or 4 MW of fuel saving in the same cogeneration system based on the operating state.