Advancing renewable energy: Strategic modeling and optimization of flywheel and hydrogen-based energy system

Abstract

This study introduces a hybrid energy storage system that combines advanced flywheel technology with hydrogen fuel cells and electrolyzers to address the variability inherent in renewable energy sources like solar and wind. Flywheels provide quick energy dispatch to meet peak demand, while hydrogen fuel cells offer sustained power over extended periods. The research explores the strategic integration of these technologies within a hybrid photovoltaic (PV)-flywheel‑hydrogen framework, aiming to stabilize the power supply. To evaluate the impact of flywheel integration on system sizing and load fluctuations, simulations were conducted both before and after the flywheel integration. The inclusion of the flywheel resulted in a more balanced energy production and consumption profile across different seasons, notably reducing the required fuel cell capacity from 100 kW to 30 kW. Additionally, the integration significantly enhanced system stability, enabling the fuel cell and electrolyzer to operate at consistent power during load fluctuations. The system achieved efficiencies of 71.42 % for the PEM electrolyzer and 62.14 % for the PEM fuel cell. However, the introduction of the flywheel requires a higher capacity of PV modules and a larger electrolyzer. The overall flywheel's efficiency was impacted by parasitic energy losses, resulting in an overall efficiency of 46.41 %. The minimum efficiency observed across various scenarios of the model studied was 3.14 %, highlighting the importance of considering these losses in the overall system design. Despite these challenges, the hybrid model demonstrated a substantial improvement in the reliability and stability of renewable energy systems, effectively bridging short-term and long-term energy storage solutions.