Computer Model for a Wind–Diesel Hybrid System with Compressed Air Energy Storage

A hybrid system combines two or more energy sources as an integrated unit to generate electricity. The nature of the sources associated varies between renewable and/or non-renewable energies. Such systems are becoming popular as stand-alone power systems to provide electricity, especially in off grid remote areas where diesel generators act as primary energy source. Wind-diesel systems are among the preferred solutions for new installations, as well as the upgrade of existing ones. However, efforts to address technical challenges towards energy transformation for sustainable development are multiple. The use of energy storage systems is a solution to reduce energy costs and environmental impacts. Indeed, efficient and distributed storage not only allows the electricity grid greater flexibility in the face of demand variations and greater robustness thanks to the decentralization of energy sources, it also offers a solution to increase the use of intermittent renewables in the energy mix. Among different technologies for electrical energy storage, compressed air energy storage is proven to achieve high wind energy penetration and optimal operation of diesel generators. This paper presents a computer model for performance evaluation of a wind-diesel hybrid system with compressed air energy storage. The model has been validated by comparing the results of a wind-diesel case study against those obtained using HOMER software (National Renewable Energy Laboratory, Golden, CO, United States). Different operation modes of the hybrid system are then explored. The impact of hybridization on time and frequency of operation for each power source, fuel consumption and energy dissipation has been determined. Recommendations are made on the choice of key parameters for system optimization.