Investigation of seasonal variations and multiple fuel options in a novel tri-generation CSP integrated hybrid energy process

Abstract

This work presents a novel Mixed-Integer Non-linear Program (MINLP) that accounts for the presence of multiple fuels in tri-generation systems. The key novelty of this work pertains to the use of hybrid energy systems in tri-generation processes, which are associated with multiple energy sources. In this work, different fuel sources such as natural gas, biomass and municipal solid waste (MSW) have been considered in the model, together with concentrated solar power (CSP), as a renewable energy option. The use of the aforementioned energy sources in tri-generation systems for heat, power and water production, were assessed simultaneously by the proposed model. CSP was utilized as the sole renewable energy option, due to the ease of obtaining both heat and power from such systems. The design of optimal tri-generation systems has been studied using the proposed model, under different conditions for carbon reduction. The model has been formulated using multi-period considerations, so as to account for seasonal variations. Moreover, the effect of several different operating parameters on the land use requirements of such systems were also investigated. The results indicate that despite the high cost of CSP, it was still found to be a highly desirable choice in the presence of carbon taxation. The water production cost of a hybrid natural gas-CSP tri-generation system was estimated at 1.277 USD/m3. This value could be 16% higher in the presence of carbon taxation. Additionally, biomass and solid waste options were found to be very promising energy outlets for desalination, especially in winter and fall seasons which have the lowest DNI values. The selection of these energy streams is also highly affected by the presence of carbon taxation policy. On the other hand, the incorporation of these two energy streams along with CSP could result in a fully local energy independent system with a water production cost of 1.44 and 1.537 USD/m3, respectively.