Performance evaluation of distributed energy system integrating photovoltaic, ground source heat pump, and natural gas-based CCHP

Abstract

A distributed energy system (DES) is considered energy-efficient and eco-friendly. However, with increasing renewable energy penetration into energy supply systems, the DES design has become diversified. This study aims to scrutinize the DES performance considering DES design characteristics and renewable energy penetration. Two DESs consisting of photovoltaic, ground source heat pump, and natural gas-based combined cooling, heating, and power with different operation strategies are modeled by TRNSYS. In DES1, the building cooling demand is first met by absorption chillers, while in DES2, it is first met by the ground source heat pump. The energy, environmental, and economic performances under different photovoltaic electricity supplies are analyzed with a cultural industrial park selected for a case study. The sensitivity analysis considering energy price and renewable electricity penetration on the system performance is also performed. The results reveal that the primary energy saving ratio and comprehensive emission reduction ratio of DES1 are respectively 5.52–13.47% and 36.76–54.09%, while those of DES2 are respectively 16.75–26.83% and 16.29–26.71%. Besides, the total cost saving ratio is 0.29–4.79% for DES1 and −14.27– -10.77% for DES2, respectively. The sensitivity analysis indicates that the cost saving ratio of the two DESs rises as the grid electricity price increases. In contrast, their trends are opposite as the natural gas price increases. The renewable electricity penetration has a greater effect on DES1 performance than on DES2 performance. This study can facilitate the better design and performance evaluation of DESs.