Design methodology and implementation of stand-alone solar photovoltaic power system for daily energy consumption of 9.16 kWh

Abstract

This stand-alone solar photovoltaic power system was designed to power a daily energy consumption of 9.16 kWh reliably, by means of photovoltaic only. The design involves different components whose capacities depend on 9.16 kWh daily energy consumption and 1-day autonomy, including several factors that determine the choice of selection. After implementation, the system was put to the test for two days to ascertain the design validity and check if it would be able to sustain the daily load demand for 24 h without failure. The results reveal that the design methodology employed for the stand-alone system in this study is accurate and reliable because the system was able to power the load interminably for 34 h, with a resulting 0.6% DoD at the end of the test. This was due to the complete energy balance that the design methodology offers. Day 1 shows that the overall PV array power was 208% higher than the daytime load power and 61.2% higher than the overall daily load power. While Day-2 shows the overall PV array power to be 130% higher than the daytime load power and 56.3% higher than the overall daily load power, The energy balance between PV array, battery, and load size was completely and sufficiently achieved on both days, as the highest depth of discharge recorded during the test was 48.7%. The study reveals that through a complete energy balance between PV, battery, and load size, a standalone PV system can reliably sustain daily energy demand. It aims to design a stand-alone PV system capable of reliably sustaining daily energy demand without the need for long days of autonomy, so as to help prevent failures in solar PV projects that come as a result of inappropriate sizing, planning, and a lack of technical know-how.