An Economical Model Development for a Hybrid System of Grid Connected Solar PV and Electrical Storage System

Abstract

Energy sources management is one of the most important concern in the recent decades. There are finite amount of non-renewable energy sources and one day they will run out if they have been used as primary sources of energy. Renewable energy sources have been significantly reduced the environmental effects. For most of them the source of energy is non-depletable. One of the concerns associated with renewable resources is uncertainty or unavailability. Energy Storage Systems (ESSs) can help to have more reliable and more efficient systems by adjusting the charge and discharge time and rate. In this study, an economic model is developed for a hybrid system of grid-connected solar photovoltaic, Compressed Air Energy Storage (CAES), and batteries. PV generation depends on irradiance and it is intermittent in nature. CAES can store energy in larger amounts and for longer periods than other storage systems and can offer lower price for stored energy. Batteries are integrated with CAES in this model mainly for lower demand and shorter periods. The presented model is a non-linear model and it’s been transformed to a linear model in this study. Optimal planning for generation and storage is derived based on the developed model for each day by using operation research techniques to maximize the value of energy which carried over the time. The results are different for each period and are highly dependent on the load demand. The results show that using solar PV panels coupled with energy storage systems increase the efficiency and reliability of the system. In addition to that, efficient use of energy storage system have a great impact on the final prices of electricity since electricity prices in low peak demand periods is lower than high peak periods.