Optimization of the operation of Grid-connected Solar PV and battery storage to minimize electricity cost

Abstract

The main objectives of this study is to minimize the electricity cost at residential house for the user of grid connected solar PV, in this thesis we use the methods of optimizing the energy generated from the solar PV system which is not used, the idea is to maximize the use of own generated power from the PV system and to minimize the dependability to the grid. In this study the method of battery optimization by using levelized cost of energy in order to know the best battery according to the battery storage technology, the simulation was done in HOMER software with the purpose of selecting the battery according to the economic point of view, life cycle of the battery and charging and discharging of battery, we found out the best battery with high cycle life and low LCOE is VRFB, Flooded LA and NaS battery technologies. After the optimization of the battery, and configuration to the grid connected solar PV system, we do the technical analysis of the energy generated from the PV system which is not used, means we have done the analysis of lost energy in the PV system generation by entering the geographical data of the selected location, PV data and the storage of the designed system in PVsyst software. After entering the required data in PVsyst software we simulate and analyses two scenario of grid connected solar PV configuration model, one with battery and the other without battery storage, the results show that the configuration system without battery storage have an unused energy or lost generated energy in the system which is equal to 17.25% of the total generated energy and the system with battery storage show that the energy generated from the PV system which is not used or lost generated energy in the system is equal to 3.76%. The analysis of two scenario was done, and we see that the system without battery storage have low installation cost which is $658 less compared to the system with storage, but this system without battery have the high percentage of energy loss of 17.25%, and this make it depend to the grid power in every time there is no sun or in night hours and this is very costly because most of the grid power is generated by using fuel and is very expensive, whereas the system with battery storage have very low energy lost 3.76% which make it very competitive according to the economic point of view, because the user of grid connected solar PV will use the maximum generated power from his own PV system and less dependability to the grid. Hence the optimum system selected in this study which can minimize the electricity cost at residential houses is the use of grid connected solar PV with battery storage.