4E analysis and multi-objective optimization of a humid air turbine cycle for compressed air energy storage system using natural gas, hydrogen, and natural gas/hydrogen blends as fuels

The development of energy storage technology is vital for addressing reliability issues associated with the integration of renewable energy into power grids. This paper focuses on incorporating hydrogen into compressed air energy storage (CAES) plants with a humid air turbine (HAT) cycle, aiming to reduce emissions and enhance system performance. A 4E analysis model is established for a polygeneration CAES-HAT system. Parametric analysis is initially conducted on systems utilizing different fuels (natural gas, hydrogen, and blends) to explore the sensitivity of six critical parameters to system performance. Furthermore, multi-objective optimization algorithms are applied to maximize exergo-economic performance, followed by an evaluation of the economic potential across various fueled systems. The results demonstrate that hydrogen blending increases the cost rate of discharge components, especially for low-pressure turbine, which reaches 2531.46 $/h. Sensitivity analysis indicates that the hydrogen-fueled system is more suitable for operation under high parameter conditions than other systems. Multi-objective optimization results demonstrate that the hydrogen-fueled system achieves best thermodynamic metrics: round-trip efficiency of 77.85%, exergy efficiency of 56.97%, and energy storage density of 11.57 kWh/m³, though at a higher levelized cost per unit exergy of 21.02 $/GJ. To align the investment payback period of the hydrogen-fueled system with that of the natural gas-fueled system, an average electricity selling price of 0.1439 $/kWh is recommended.