Economic Analysis of Residential Grid-connected Photovoltaic System with Lithium-ion Battery Storage

Residential roof-mounted photovoltaic (PV) system paired with battery storage systems can minimize dependence on grid electricity and reduce electricity bill. Moreover, the economic viability of such systems is subject to the efficient utilization of excess electricity generated, most often with the aid of net metering. In recent time, energy storage market is exponentially growing and batteries are being installed in a grid-connected household to maximize the use of on-site electricity generated by PV. Nevertheless, batteries have not yet reached economic profitability in most grid-connected scenarios. Moreover, the economic and technical viability of such systems is still under discussion. This work, therefore, presents the optimization results of residential grid-connected PV system paired with a lithium-ion battery (LiB) of a household located in Yobe, Nigeria. The model is implemented in Matlab environment. The model takes into account both technical and economic parameters, such as battery state of health and state of charge over a period of time, storage investment cost, and electricity price. Moreover, the power flow paths at different interval of time are demonstrated and the result of the sensitivity analysis in term of return on investment (ROI) is presented. The results obtained shows that the ROI dependent on so many factors such as electricity price and energy storage system price. We also identify that PV system with LiB if installed; the household electricity bill will result in an earnings of €2943 because of the less energy consumption from the grid of about 45.7% less as compared with the case without LiB.