Comparison of Models to Evaluate Daily Available Energy with Photovoltaic Array at Sirinka, Ethiopia

Abstract

Background: Energy utilization in Ethiopia is mainly based on traditional biomass, which causes indoor air pollution, especially for women and children (causing acute lower respiratory infection) living in rural areas.

Objective: This research was conducted to assess the performance of six empirical models for estimation of daily global solar radiation (DGSR) at Sirinka sites to evaluate daily available energy with photovoltaic (PV) array and energy available to the load (energy demand) and battery (energy-storage device).

Materials and Methods: In this study, sunshine hours, minimum and maximum temperatures were obtained from Kombolcha Meteorological Agency. Ms-Excel 2010 was employed as a descriptive statistics tool and MATLAB 2013a was used as software to plot the analyzed data.

 Results: According to the statistical performance evaluation metrics, such as normalized mean bias error (NMBE) and normalized root mean square error (NRMSE), Angstrom Prescott model (AP), Louche model (LO) and Hargreaves model (H) performed best in order. The smallest daily mean power delivered to PV and the daily mean energy available to the load (energy demand) and battery (energy-storage device) were 288.11 W/m² and 248.92 W/m² sequenced and the largest mean power delivered to the PV and the mean energy available to the load and battery were 851.57 W/m² and 735.76 W/m² in order on April-10 for the study period of 2014–2018.

 Conclusion The result of this work showed high solar energy potential and therefore, rural electrification using PV system is possible in the study area and can reduce health problems due to indoor pollution in the future.