Scheduling strategy for an electricity-heat-gas hybrid energy storage microgrid system considering novel combined heat and power units
Nan Chen, Junheng Gao, Lihui Gao, Shuanghao Yang, Shouyan Chen
Abstract
Against the backdrop of rapidly increasing renewable energy penetration, many regions are facing the phenomenon of power abandonment. To enhance the absorption capacity of renewable energy, constructing an integrated energy system holds significant economic and environmental benefits. This study first introduces a power-to-gas (P2G) conversion technology incorporating an intermediate buffer link, and constructs an electric-heat-hydrogen-natural gas energy hybrid storage system. The P2G process can be further detailed into two stages: power-to-hydrogen and power-to-natural gas, and a two-stage bidirectional coupling system of "electric-hydrogen-electricity" and "electric-gas-electricity" is formed through fuel cells and gas turbines, respectively. Secondly, concentrated solar power plants and fuel cells are regarded as a novel combined heat and power (CHP) unit, replacing traditional CHP methods. Additionally, flexible load technology is introduced to participate in the scheduling of the integrated energy system. Finally, an economic dispatch model for the electric-heat-gas integrated energy system was developed, and the optimization problem was addressed using a mixed-integer programming algorithm. The results indicate that incorporating flexible loads reduces the total cost by 1.32 %, power curtailment losses by 13.93 %, and the electric load peak-to-valley difference by 22.05 %. With the integration of P2G technology, the total cost decreases by 1.92 %, and power curtailment losses by 79.92 %. The introduction of a novel CHP unit lowers the total cost by 5.88 %, cuts carbon emissions by 49.15 %, and decreases the all-day gas purchase by 24.49 %. These results demonstrate the feasibility and effectiveness of the proposed approach.