A hydrogen-fuelled compressed air energy storage system for flexibility reinforcement and variable renewable energy integration in grids with high generation curtailment

Globally, the increasing share of renewables, prominently driven by intermittent sources such as solar and wind power, poses significant challenges to the reliability of current electrical infrastructures, leading to the adoption of extreme measures such as generation curtailment to preserve grid security. Within this framework, it is essential to develop energy storage systems that contribute to reinforce the flexibility and security of power grids while simultaneously reducing the share of generation curtailment. Therefore, this study investigates the performance of an integrated photovoltaic-hydrogen fuelled-compressed air energy storage system, whose configuration is specifically conceived to enable the connection of additional intermittent sources in already saturated grids. The yearly and seasonal performance of the integrated energy storage system, specifically designed to supply flexibility services, are evaluated for a scenario represented by a real grid with high-variable renewables penetration and frequent dispatchability issues. Results show that the integrated system, with performance-optimized components and a new energy management strategy, minimizes photovoltaic energy curtailment, otherwise around 50%, to as low as 4% per year, achieving system efficiencies of up to 62%, and reinforces the grid by supplying inertial power for up to 20% of nighttime hours. In conclusion, the integrated plant, operating with zero emissions, on-site hydrogen production, and optimized for non-dispatchable photovoltaic energy utilization, proves to be effective in integrating new variable renewable sources and reinforcing saturated grids, particularly during spring and summer.