Economic and environmental optimization for distributed energy resource systems coupled with district energy networks

This study aims to optimize DER (distributed energy resource) system with respect to economic and environmental objectives. In particular, we developed a mixed-integer linear programming model with multiple objectives at a neighbourhood level containing residential and office buildings. The equipment and layout of the district energy (power, heating, and cooling) networks were selected from several potential energy devices and paths using a mathematical model. The objectives of the model were to minimize the total annual cost and CO2 (carbon dioxide) emission and achieve the optimal design and operation to meet the yearly energy demands. Moreover, the economic and environmental benefits under different weights of the objective function were evaluated by sensitivity analysis. The results show that at a neighbourhood level, the DER system has significant environmental and economic benefits. The system could spontaneously select the most appropriate operation strategy using the developed mathematical model. In multiobjective scenarios, with the increase in the weight of environmental factor, the emission decreases and the cost increases gradually. When considering a single objective, the minimization of cost or carbon emission leads to a poor cost performance.