Energy performance assessment of a polygeneration plant in different weather conditions through simulation tools

•Energy assessment of a polygeneration plant through the combined management of thermal and electrical renewable technologies.•Two TRNSYS models have been developed to evaluate the thermal and electrical operation of the plant.•Conventional systems have not been included into the TRNSYS models.•Optimal operation maximizes the renewable fraction and minimizes the energy surplus.•Global results are the quantification of the renewable influence on the annual coverage. This paper analyzes theoretical dynamic performance of centralized polygeneration technologies using district networks as distribution system. Three Spanish cities have been studied using as input variables Typical Meteorological Years (TMY), representative local constructions and normative internal loads for residential and tertiary buildings. Energy simulation has been carried out with the software TRNSYS. Different dynamic models that connect renewable and conventional technologies have been developed to represent the thermal and electrical performance of a polygeneration plant. The thermal model is based on the combined operation of solar thermal collectors and biomass boilers using cogeneration systems as a backup when both renewable technologies cannot supply the thermal district loads. The electrical model is based on the independent operation of photovoltaic panels and wind turbines in combination with Polymeric Electrolyte Membrane (PEM) fuel cells. Global systems work at their limit operation to compare the final results of the three cities. Different configurations have been studied to evaluate the annual thermal and electrical coverage reached by the plant. Once optimized the area of the solar field the energy fraction covered by the renewable systems increases logarithmically with the power of the biomass boilers. The simultaneous operation of photovoltaic panels and wind turbines to feed PEM cells maximize the electrical coverage achieved by the district. Results of both simulation models show that for all weather conditions studied, the optimal solution is a combined operation of the renewable technologies used.