Planning and Investment Decisions for a Highway Self-Sustained Microgrid System

Longfei Cheng

Abstract: To address the challenges of highway energy supply in remote areas, renewable energy intermittency, and the limitations of conventional diesel-based power supply, this paper proposes a coordinated source-storage-load planning framework for an off-grid Highway Self-Sustained Microgrid System (HSMS). An optimal sizing model is developed with the objective of minimizing the equivalent annual cost, subject to constraints on power balance, energy storage operation, distributed generation output, and conventional generation unit operation. A case study based on an actual highway section is conducted to verify the proposed method. The results show that, compared with battery-only and hydrogen-only storage schemes, the battery-hydrogen hybrid storage scheme reduces the annual total cost by 2.72% and 6.56%, respectively, while lowering the renewable energy curtailment rate to 0.38% and the outage rate to 0.26%. Hybrid energy storage effectively combines the fast response capability of batteries with the long-duration energy shifting capability of hydrogen storage, thereby enhancing the economic performance, renewable energy utilization, and supply reliability of off-grid highway energy systems. The proposed approach can provide theoretical support for the low-carbon and energy-autonomous development of highway energy infrastructure in off-grid regions.

Keywords: Integration of energy and transportation; Highway Self-Sustained Microgrid System; Optimal sizing; Hybrid energy storage