•Round trip efficiency improvement by combining the desalination and storage units.•Simultaneous generation of the power and potable water during peak demand periods.•An efficient and green cogeneration system for using in warm and arid climates.•Waste heat recovery from the compressors and the turbine exhaust.•Impact of the maximum to minimum pressure ratio on performance and operational time. Compressed air energy storage is one of two existing grid-scale energy storage technologies. It can be efficiently used in dry and warm climates, where providing both electricity and potable water is indispensable. A novel integration of compressed air energy storage and multi-effect desalination system is proposed to reduce energy dissipation, exergy destruction and provide power and potable water. Compression heat in the charging period is conveyed to the desalination unit; during discharging, the remaining energy in the turbine exhaust is reassigned to the desalination unit after passing through the recuperator. Round trip efficiency is thereby improved while providing peaking power and pure water. Besides, the effect of the maximum to minimum pressure ratio of the compressed air vessel on efficiency and the operational period of the system is studied for a particular set of circumstances. Results indicate that 38 kg/s potable water is produced during charging, whereas 80 MW electricity and 62.5 kg/s distilled water are concurrently generated during peak demand periods. As a result, 69.95% round trip efficiency and 9.47 performance ratio are obtained for the proposed hybrid system.