Multi-objective capacity configuration optimization of an integrated energy system considering economy and environment with harvest heat

Integrated energy system characterizes with improving cascade utilization rate of energy and efficient energy conservation and substantial carbon reduction. Aiming at the total annual cost and annual carbon emission of integrated energy system, the capacity optimal configuration model of integrated energy system based on the principles of cooling determining heat and heat determining electricity is established in this paper, considering energy complementary coupling characteristic and distribution ratio. Moreover, Non-dominated Sorting Genetic Algorithm-II combined with Technique Order Preference by Similarity to an Ideal Solution comprehensive solution model is adopted to achieve the optimal solution under Pareto solution set. The configuration result reflected that renewable energy is preferred, and there are more electricity storage devices with less electricity equipment. Furthermore, the optimal operation schemes of three typical season days are analyzed and compared, specifically presenting the effectiveness of the operation strategy proposed in this paper. In addition, waste heat originated from integrated energy system and harvested by ORC is analyzed herein, which highlights generating electricity with 2.19 × 104 kWh totally participating in operation of power subsystem and reducing CO2 emissions by 15.056 tons. Furthermore, the sensitivity of carbon emission factors is analyzed, achieving that there is a Carbon Singular Point with 0.18 kg/kWh of natural gas emission and 0.98 kg/kWh of power grid emission respectively in the optimization process, which is significant for multi-objective optimization and construction of Integrated energy system.