Identification and evaluation of the losses occurring in a solar PV system under real field conditions for rural electrification in Humla

摘要

Nepal, which is situated along the solar belt of 30° northern latitude, is blessed with an average of 300 days of sunshine a year. Over the last decade, private companies and local NGOs/INGOs have been increasingly providing electricity services through government subsidised Solar Photovoltaic (PV) Systems to the local communities for basic indoor lighting in rural areas. In many cases, the users consider PV technology to be inappropriate when the performance of their solar PV system is less than what they expected or were initially promised. The understanding of the real field conditions in a set environment, as well as the losses occurring due to PV cell temperatures, PV module mismatches, wrong battery bank usage etc. are lacking, not discussed or considered in the design of a PV system prior to its installation. ududIn order to identify and understand the losses which may occur in installed solar PV systems, and thus understand their limited performance in greater detail, Kathmandu University (KU) and Rural Integrated Development Service (RIDS)–Nepal, with the support of the ISIS Foundation, have started monitoring several solar PV systems' performance on a continual basis within their installed geographical, meteorological and users' context in one of the remotest and poorest communities in Humla, Nepal. This paper aims to identify and present the main losses in a solar PV system. In particular, losses occurred due to non-standard temperature conditions (STC), non-ideal PV module angle position, increased PV cell temperature, PV module mismatch, and battery bank and wire losses, are discussed and presented with data, graphs and pictures.