Household Solar Adoption in Kathmandu Valley, Nepal: Affordability, Energy Security and Policy Pathways for Sustainable Development

Abstract

Nepal’s scattered settlements, difficult topography and fuel-import dependence make a strong case for decentralized household solar energy, but adoption depends on affordability, operational performance and policy support. This study examines the financial viability of household solar systems in Kathmandu Valley and their implications for rural energy access and sustainable development. A mixed-method design combined a structured survey of 110 households across Kathmandu, Bhaktapur and Lalitpur, open-ended interviews with 10 energy-sector experts, and a review of relevant policy and literature. Internal consistency of the 12-item instrument was high (Cronbach’s α = 0.941). Most respondents reported annual solar generation of 2,001–4,000 kWh, system efficiency of 60–80%, expected lifespan of 10–20 years and annual energy cost savings of NPR 10,001–20,000. Annual savings were positively associated with annual generation (r = 0.533), energy efficiency (r = 0.573), reliability (r = 0.642), maintenance-interval coding (r = 0.727) and expected operational lifespan (r = 0.714), all p < 0.001. An exploratory regression using the composite financial variable to predict financial feasibility yielded R = 0.489, R2 = 0.239, F(1, 108) = 33.984, p < 0.001, explaining approximately 23.9% of the variance in financial feasibility. Expert evidence identified cost, awareness, storage and policy barriers, while targeted finance, subsidies, installer standards, monitoring and grid improvements were key to strengthening adoption and energy security. A regional comparison situates these findings within the wider South Asian household-solar transition, suggesting the financing, storage and institutional barriers identified are transferable to neighbouring countries with comparable resource and policy conditions.