A new renewable energy system integrated with compressed air energy storage and multistage desalination

Energy security is recognized as one of the most significant issues that countries are keen on liberating them-selves from for stable economies and clean environments. Such concerns can only be eliminated by relying more on renewables, such as solar and wind energies. This study proposes a novel integrated solar and wind-driven energy system for a sustainable community, potentially in Antigua and Barbuda. The current system is devel-oped to provide the community with electrical energy and freshwater from renewable resources rather than the presently operating imported heavy fuel oil-based energy supply. Excess power is stored mechanically via compressed air energy storage (CAES) system using underwater balloons as storage medium to minimize the use of valuable onshore land for such an island nation. The waste heat occurring from the air compression is captured and used in an Organic Rankine Cycle (ORC), operating with isobutane working fluid, to minimize losses while increasing the system effectiveness. Both energetic and exergetic efficiencies of the proposed system are also evaluated comparatively through thermodynamic techniques. The parametric studies are then conducted to further evaluate the system performance under various operating conditions. The system provides 365 GWh of electrical energy on an annual basis. In addition, the current multistage seawater desalination unit is designed to produce a total of 376 tons of fresh water. The system is potentially capable of fueling 168 in-city pneumatic vehicles daily. The overall energetic and exergetic efficiencies of the integrated system are evaluated and found to be 62.8% and 48.5%, respectively.