Mountainous hinterland in rural Nepal lacks fundamental social infrastructure. Lack of electricity causes difficulty of water provision, especially in mountainous area where villagers, especially ladies, youths and children, often spends large amount of time just to convey water. To overcome this challenge, installation of solar water pumping system (SWPS) is recently being implemented nation-wide in Nepal. Confrontation of the Nepali government with her tight financial constraint requires the installation process be both economically and technologically sound. By collecting original field data from 38 wards (i.e., villages) in all seven regions in the entire Nepal, this paper thus identifies the technically efficient cases of SWPS, and then investigates any potential economic policy that will enhance the performance of SWPS. Our results show, inter-alia, that abundant financial support from the government results in inefficient systems, and that charging user fees significantly discourages villagers' participation to SWPS and hence undermines the potential benefit of SWPS.