Examining The Techno-Economic Viability of Institutional Energy Generation Through Rooftop Solar Photovoltaic - A Case Study

Abstract

Use of institutional rooftop solar photovoltaics (PV) is considered as a potential alternative to
address energy deficit in low middle-income countries. This study aims to conduct techno-economic
feasibility assessment of rooftop solar PV taking a sample case of a school in Kathmandu valley.
Comprehensive questionnaire survey and field measurement are done to determine load demand
and energy usage habits of the institution. PVSyst is used to develop an optimized rooftop solar PV
system with a total capacity of 72.6 kWp. Technical feasibility study is done through performance
ratio and loss diagrams, and economic feasibility study is done through determination of payback
period. Performance ratio of 85% was achieved, and design losses are within acceptable range. The
highest losses are seen in soiling and temperature derating which was below 4%. The designed
system has an annual yield of 121.56 MWh, payback period of 6.7 years and return on investment
of 211.4% after the payback period. For validation, the simulated results are compared with data
logged in a comparable institution with a net metering system. The simulation for this institution
was carried out using an identical regime. The payback period of 11.5 years was empirically
calculated through the logged generation/usage data whereas the simulation result showed a
payback period of 11.8 years, which is in acceptable range. This study shows that institutional
rooftop solar PV is both technically and economically viable in Nepal.