Return of Interest Planning for Photovoltaics Connected with Energy Storage System by Considering Maximum Power Demand

In this study, a general building of medium size with an Energy Storage Systems (ESS)-connected Photovoltaic (PV) system (energy storage system that is connected to a photovoltaic system) was chosen to develop a tool for a better economic evaluation of its installation and use. The newly obtained results, from the revised economic evaluation algorithm that was proposed in this study, showed the effective return of investment period (ROI) would be 8.62 to 12.77 years. The ratio of maximum power demand to contract demand and the falling cost of PVs and ESS was the factors that could affect the ROI. While using the cost scenario of PVs and ESS from 2019 to 2024, as estimated by the experts, the ROI was significantly improved. The ROI was estimated to be between 4.26 to 8.56 years by the year 2024 when the cost scenario was considered. However, this result is obtained by controlling the ratio of maximum power demand to contract demand. Continued favorable government policies concerning renewable energy would be crucial in expanding the supply and investment in renewable energy resources, until the required ROI is attained.