Low cost operation of an off-grid wind-PV system electrifying residential homes through combinatorial optimization by the RCGA

Abstract

A low power off-grid wind-photovoltaic system is increasingly used to energize residential homes in remote areas where no grid utility or grid extension is available. An economic design of such a system for 20-year lifetime requires optimal unit sizing as well as investment, operation and maintenance costs. However power generation by this system varies from one day to another due to irregular natures of wind speed and solar irradiation. Therefore battery storage is needed to integrate into this system if all the electrical appliances are desired to uninterruptedly feed and this requires to efficiently manage battery operation. Besides, load shifting can be applied to such a system through controllable loads in order to balance generation and consumption at each time interval as much as possible. One way to balance generation and consumption in a specified period is possible to solve a discrete optimization problem defined as minimization of daily cost with few constraints for optimal time slots. In this study, minimization of total cost for such system is achieved by the real-coded genetic algorithms technique from various aspects. The results obtained are meaningful and encouraging to design and operate such a low cost system.