Design of a Stand-Alone Rooftop PV System for Electrification of an Academic Building

Abstract

Solar energy is one of the most promising options of renewable energy in the context of energy sustainability. Nowadays, as the utilization of solar energy has been continuously expanded in wide scale, researches related to the topic have been carried out all over the world. The prime focus of this study is to provide sustainable energy generation for an academic building located in a rural place, where power outage is a frequent issue. In this study, individual power system components have been suitably designed which could electrify the building for yearlong use. A rooftop photovoltaic (PV) system with three days battery backup has been considered for the present case. Designing of the PV system is based on the selection of individual electrical appliances and its operating time in a day. For this purpose, a survey has been carried out over a year in order to identify the day in which maximum power was utilized. The study revealed that the total estimated capacity of the stand-alone PV system should be 138.6 KWp in which 446 PV modules bearing 300 Wp each are connected together in series parallel combination. Total 656 numbers of batteries (12V- 200Ah each) are required for power backup which store the excess PV generation. Suitable size also been considered for inverters and charger controller which are connected in parallel and series respectively. The area required to install PV modules on the rooftop without shadow effect has been properly assessed. Besides being PV system design, brief cost analysis has been carried out in terms of simple payback period, unit cost of power generation and cash flow in terms of present value.