Impact of renewable energy penetration in power systems on the optimization and operation of regional distributed energy systems

The performance of regional distributed energy systems is closely related to operation strategies and is also affected by the renewable energy penetration rate of the power system. According to the load characteristics of a public building in Changsha, a regional distributed energy system of a combined heating and power unit coupled with a photovoltaic, ground source heat pump, air-source heat pump, and energy storage is proposed to explore the impact of the power system's renewable energy penetration rate on its optimization and operation. Based on the following electric load, following thermal load, and following hybrid electric-heating load strategies, this paper conducts a multi-objective optimization design for the proposed system according to two scenarios, where Scenario 1 considers the change of renewable energy penetration in the power system, and Scenario 2 does not. According to the optimization results, the impact of the change in the power system's renewable energy pene-tration rate on the system performance is comparatively analyzed. The results show that the electricity con-sumption share of the system from Scenario 1 is greater than that of the system from Scenario 2, regardless of the design and operation conditions. With the increase of renewable energy penetration, the primary energy saving rate of the system from Scenario 1 is higher than that of the system from Scenario 2, with increasing rates of 37.60%, 7.92%, and 36.87% under three strategies, respectively. Furthermore, for Scenario 1, the system operation performance under the following thermal load strategy is better than that under the other two stra-tegies. The results of this paper provide some guidance for the optimal design of grid-connected distributed energy systems.