Azimuth Angle for Eight Cardinal Directions to Decrease Energy Imports in On-Grid Rooftop Solar PV System: a Case Study of Indonesia

On-grid rooftop solar PV is a viable solution to reduce energy imports from fossil generation power grid. In Indonesia, there is an estimated 32.5 GW energy potential from rooftop, which has not been optimally explored. To maximize this potential, careful assessment of several factors such as building roof shape, slope, location, local weather, and azimuth angle, is required to ensure optimal solar PV design and massive installation across different locations. Therefore, this study aimed to analyze azimuth angle of eight cardinal directions in the capital city of Indonesia to decrease energy imports from the grid. By adjusting the orientation and shape of rooftop according to the sun's orbit using eight cardinal directions, the optimal azimuth angle was determined to minimize energy imports from the grid at 0 and-90 degrees. Tilt angle of solar PV was also adjusted to correspond with roof angle ranging from 2 to 18 degrees. Based on the results, the lowest energy import of 5338 kWh/year was found in the capital city of Denpasar, which applied to various roof standards including Flat, Gable, Hip, Mono-Pitch, and Mansard. In comparison, the highest import was found in Pontianak City, with energy of 9157 kWh/year applied to Hip roof model. This showed that eight cardinal directions for determining azimuth angle could be implemented for on-grid rooftop solar PV planning.