A Device to Determine the Panel Orientation for Best Annual Solar Energy Generation at a Selected Location

Abstract

AbstractWithin the past few years, solar photovoltaic (PV) power generation has gained popularity along with sustainable concepts around the world. The low efficiency of PV systems could be identified as a leading drawback of energy conversion. Panel tilt angle and direction directly affect the amount of irradiance incident on solar panels, governing the amount of energy generated. Assuming ideal conditions, fixed panels are installed to face the equator, as used in common practice, while the tilt angle is kept equal to the latitude of the location. Due to the uniqueness of geographic and weather conditions in different locations, the irradiance patterns may deviate from the ideal. Thus, the optimum panel orientation may differ from conventional practise. Thus, the objective of this study was to introduce a universal method which can determine the location-specific optimum orientation of solar panels. The in-situ weather and irradiance data were captured for a period of time (approx. 30 weeks) at a given location. In addition, weather data at the location was collected for the past few years via relevant authorities. A mathematical model was developed to extrapolate the irradiance incident on various orientations using available data as a guideline for an average year. The orientation that is expected to capture the highest amount of irradiance was determined as the optimum orientation. Then, a case study was carried out following the above methodology at the department of mechanical engineering, University of Moratuwa. The analytical results showed that the overall efficiency of the PV system was increased by 0.4% compared to that obtained with the generic tilt (i.e. 7°) setup. The efficiency of the entire system could be increased without an additional cost if such analysis is conducted prior installation. The analysis would be more appropriate for large scale solar farms rather than domestic installations.KeywordsSolar PVPanel orientationOptimum generationIrradiance modellingFixed orientation