ESTIMATION OF SOLAR PHOTOVOLTAIC GENERATION YIELD BASED ON ROOFTOP TILT ANGLE

Abstract

Solar photovoltaic (PV) based power systems are being deployed more often in order to satisfy increasing energy requirements and global decarbonisation campaigns. Precise estimation of PV yield is essential for sizing systems, performance optimization and long-term planning. One limitation of existing models, including the Sustainable Energy Development Authority (SEDA) Malaysia formula, is that it does not provide a good approximation to different roof slopes and orientations. As a result, this led to less accurate performance estimates e.g. on tilted or multi-roof-top plate configurations. As such, this paper proposes a better method for predicting PV output by generating accurate factors and fitting formulas with respect to roof tilt and azimuth. LossFactor models were produced using PVSyst for different tilt and azimuth settings for all the Malaysian state capitals. Key parameters including global irradiance and temperature dependence, as well as module and system losses were deduced to study the influence of geometrical parameters on overall performance. Tilt angles ranging from 0° to 60° and azimuth orientations of south, east, and west were analyzed. A polynomial-based predictive model using a compiled data set was developed to estimate the optimal tilt–azimuth pairs for an annual energy production. The accuracy of the model was validated through on-site measurements and this model was consistent with the simulation output. Many researchers state a consistent and significant interaction between roof structure and the PV efficiency, where the improvement in energy output deviations resulting in measurable losses was determined by the optimal configuration. This study introduces a robust and practical method to enhance PV yield estimation through integration of simulated data, mathematical modelling and field validation.