Tilt Angle and Orientation Assessment of Photovoltaic Thermal (PVT) System for Sub-Saharan Tropical Regions: Case Study Douala, Cameroon

Abstract

Photovoltaic systems when integrated into a building structure can satisfy the world’s energy requirements at a competitive cost by providing onsite electrical and thermal energies for domestic appliances. The energy yield of the photovoltaic system is affected by the intensity of the solar radiation, wind speed, tilt angle, orientation, geographical location, etc. This paper presents an optimisation model of the tilt angle and orientation of a photovoltaic thermal system. A methodology has been developed to optimize the tilted angle of the roof for higher exergy output taking into account the intensity of solar radiation, wind speed, geographical location, cost of cleaning dust, etc. For a system installed in the city of Douala, Cameroon, it is recommended that the PV should be inclined at an angle between 10° and 20° south-facing for economical output. The cost per unit of electricity between the tilt inclination angles from 0° to 20° with south orientation is USD 0.04 per kWh. The cost of electricity loss due to a 20° tilt inclination angle can be compensated with the labour cost and work required for cleaning the photovoltaic thermal (PVT) system of the horizontal roof. The system installed over an effective area of 8 m2 is capable of producing annual net exergy of 2195.81 kWh/year at an efficiency of 11.8%.