ASSESSMENT OF SOLAR PHOTOVOLTAIC POTENTIAL IN ROOFTOP OF PRIVATE HOUSING SECTOR OF KATHMANDU VALLEY

Abstract

Solar energy has become a significant form of power generation on many electricity networks in recent years. Though Nepal is rich in water resources, it has been struggling with the energy scarcity because of constraints in accessibility, financial ability, and policy for the development of hydropower. Similarly, the complication of transporting wind turbines, financial availability and improper resource assessment has created a barrier for harvesting energy through wind. Further, the enormous fossil fuel imported through the governmental companies has fulfilled the demand of cooking and transportations which has become the sole emitters of greenhouse gases. However, Nepal has significantly higher solar radiation which could be a positive option to produce solar electricity through effective ways. The urban areas of Nepal are the largest consumers of electricity because of rising urbanization and preference of an advanced way of living standards. The development of massive high-rise buildings and a cluster of housings from the private housing sectors are coping with this increased urbanization. The housing sectors have been built with the approach of energy harvesting and saving strategies. Under the present study, an attempt has been made to estimate the rooftop photovoltaic potential in an area of Nepal. So, the study has estimated the rooftop solar photovoltaic potential on 17 active housing sectors around Kathmandu valley. The photovoltaic potential on rooftop involves the calculation of physical potential as the total solar energy on the rooftop, unshaded area for photovoltaic installation as geographic potential and electricity generation potential on an hourly basis throughout the year. The Hillshade algorithm based on the position of Sun in the Sky has been used to obtain geographic potential. The study has finally estimated that the physical potential of 343,858.25 MWh at the tilted surface of 30º with the horizontal and azimuth of 180º, geographic area of 100,913.80 m2 accounting for 58.04% of total rooftop area remain unshaded and electricity generation potential of 15,891.42 MWh. The electricity thus generated can meet about 40% of the electricity demand of the residential sector of Kathmandu valley. Based on encouraging result of estimated rooftop photovoltaic potential, it is recommended to change the policy of the country in order to tap this potential in the rooftop photovoltaic system in urban areas of Nepal