Hybrid Energy Storage System to Enhance Efficiency of Renewable Energy Usage

Recently, the world has been aware of global warming caused by CO2 emissions, turning to the use of renewable energy sources (RESs) from solar, biomass, and wind. However, such power generation from RES produces an imbalance between power supply and demand, affecting the quality and reliability of power systems with RES installations. Therefore, managing the available loads to respond to power demands efficiently is a critical issue. This paper presents a hybrid energy storage (HESS) technology based on the collaboration principle of battery energy storage systems (BESS) and solid oxide fuel cells (SOFC). The responsibilities of the energy storage system are divided into two parts. The first part is for the transient condition; BESS helps the system cope with sudden load changes. The second part is for the steady-state condition; SOFC serves the system over the long term to withstand fluctuations and support renewable energy to smoothly supply power to the system. To illustrate the effectiveness of the proposed method, a power system with a hybrid energy storage system installation is simulated by using DIgSILENT PowerFactory software. The simulation results exhibit that the interaction of SOFC and BESS can effectively manage the power flow in a power system with renewable energy installation. BESS can immediately help stabilize the system frequency during severe disturbances, while SOFCs can increase the flexibility to meet the power demands throughout the day. Moreover, the proposed hybrid energy storage system allows renewable energy to supply power consistently, improving the overall power system's stability, quality, and reliability.