Assessment of urban rooftop grid connected solar potential in Nepal,a case study of residential buildings in Kathmandu, Pokhara and Biratnagar cities

Résumé : This paper assesses the technical, financial, and market potential of the rooftop Solar Photovoltaic (PV) system on residential buildings in major cities namely Kathmandu valley, Pokhara, and Biratnagar of Nepal. Three sets of questionnaires were prepared each for residential households, PV suppliers, and solar project financing institutions. From the field survey, it is found that the average rooftop area available for PV installation is 14.5 sq.m, 12.45 sq.m, and 19 sq.m in Kathmandu, Pokhara, and Biratnagar cities respectively. Considering 557,027 residential buildings in Kathmandu; 77,523 in Pokhara and 33,075 in Biratnagar, total rooftop PV power potential in all three cities are found to be 970 MWp which could generate 1,310 GWh/year that comes out to be 35% of the electricity sold by Nepal Electricity Authority (NEA) in fiscal year 2014/15. Based on the 1.5 kWp PV system design per household and market price of 2016, the Levelized Cost of Electricity (LCOE) changes from NRs 8/kWh to NRs 20/kWh for basic lighting to a full load consisting of domestic electrical appliances. The technical barriers for the grid connection of rooftop solar in Nepal are not a major issue now as Nepal Electricity Authority has set clear guidelines for it.