3E (energy, economic, environmental) multi-objective optimization of CCHP industrial plant: Investigation of the optimal technology and the optimal operating strategy

The article describes the application of an innovative multi-objective optimization model for tri-generative en-ergy systems, based on three objective functions: technical, economic, and environmental. The proposed algo-rithm was used to simulate the daily operation of several tri-generative system configurations, counting for a total of 31,680 simulations. Thereafter, a critical examination of the data was carried out and then comparisons were made between the 22 studied technology sets, by considering internal combustion engines, solid oxide fuel cells, proton exchange membrane fuel cells, absorption heat pumps, and compression gas heat pumps, lithium -ion, and lead-acid batteries. For the analyzed case study, relating to a large industrial user, the average electrical load in the four reference periods is equal to 4970 kW. The optimal tri-generation plant for this type of user turned out to be composed of: SOFC fueled by methane with a size of 5 MWe, a lithium-ion storage system with a maximum size of 500 kW, an absorption heat pump with a size of 390 kW, gas compression heat pump for the generation of cooling energy with size equal to 390 kW, and gas compression heat pump for the generation of thermal energy with size equal to 1600 kW.