The examination of a multi-generation structure powered by a compressed air energy storage system for sustainable power, freshwater, and cooling load

Abstract

The presented study brings out a novel compressed air energy storage system integrated with a multi-generation system to address fluctuating power demands sustainably. The system incorporates three storage units, solar thermal energy, compressed air, and compressed air heat, designed to support electricity generation, freshwater production via a multi-effect desalination unit, and cooling through an absorption refrigeration cycle. Comprehensive analyses, including energy, exergy, exergoeconomic, and techno-economic evaluations, reveal critical insights into the system's performance and cost-effectiveness. A prolonged charging period decreases round-trip efficiency from 43.96 % to 40.48 % and exergetic round-trip efficiency from 35.74 % to 34.90 %. Extending the discharging period from 3 to 8 h elevates the net present value from 119.71 $M to 138.64 $M while maintaining stable performance. The solar tower demonstrates the maximum exergy destruction rate at 289891.56 kWh, which contributes 28.93 % of the system's total exergy destruction, while the air turbine incurs the maximum exergy destruction cost at 4.94 $M/year. At optimal operation, the system consumes 97.52 GWh of power and delivers 98.32 GWh during discharging, alongside freshwater production of 24.82 kg/s and a cooling load of 8310.73 kW. With a round-trip efficiency of 46.68 % and an exergetic round-trip efficiency of 37.32 %, the system achieves a payback period of 1.74 years and a unit product cost of 22.94 $/GJ, demonstrating its feasibility as a sustainable solution for multi-generation applications. The proposed structure suggests a sustainable solution for integrating renewable energy, stabilizing power grids, and supporting desalination in energy- and water-scarce areas.