Contents lists available at ScienceDirect Renewable and Sustainable Energy Reviews journal homepage: www.elsevier.com/locate/rser Issues in PV systems applied to rural electrification in Brazil L. Roberto Valer a, ⁎ , Alex. R.A. Manito a , Tina B. Selles Ribeiro a , Roberto Zilles a , João T. Pinho b a Instituto de Energia e Ambiente, Universidade de São Paulo, Av. Prof. Luciano Gualberto 1289, CEP 05508-010 São Paulo, Brazil b Grupo de Estudos e Desenvolvimento de Alternativas Energéticas (GEDAE), Universidade Federal do Pará (UFPA), Campus Universitário do Guamá, CEP 66025-772 Belém, Brazil ARTICLE INFO Keywords: Rural electrification Solar home systems Solar micro-grids ABSTRACT In Brazil, the access to electricity is a right of all their citizens. The Brazilian government has endeavored to extend the electric grid wherever technically and economically feasible. For the remaining sites, PV systems can be a feasible option that is enforced by federal laws, standards and subsidies. For this reason, unlike other countries where renewable energy systems are donated or commercialized by NGOs and other entities, in Brazil these systems are mainly installed by utilities, making the country a unique case for study. This paper analyzes the main problems faced by PV systems for rural electrification. The methodology is based on field observation and literature survey. As a result, several issues of demand to be supplied, installation, operation and maintenance, and post-installation were identified. From these observations, it is clear that a greater attention should be payed to the management of the whole electrification project, by clearly delimiting the goals and the responsibilities of each stakeholder, and ensuring that the goals are met. 1. Introduction Access to electricity is closely associated with human development. The potential benefits that may arise from rural electrification projects are many, and have strong influence on increasing the Human Development Index (HDI) of a community in the early stages of its development [1]. Despite this, a considerable portion of the world's population still lacks access to electricity and the benefits it can bring. According to the World Energy Outlook 2012 [2], at that time almost 20% of the world's population did not have access to modern energy and still used traditional energy sources such as wood, kerosene, and candles to meet their energy needs. In Brazil, although access to energy is a right of all citizens established by law 10,438 [3], according to the last census [4], around 716,000 homes did not have access to electricity. Brazil started addressing rural electrification mainly through con- ventional grid extension, prioritizing those locations closer to larger cities from which the grid could be easily extended. This was done due to reasons such as the lower average marginal cost of providing the service, and the higher expertise of the utilities with this type of service. Connection to the existing grid, however, is not possible for many remote and isolated communities, due to logistic, environmental and geographic factors. Isolated communities also often have low load density, not justifying the costs and environmental impacts of the grid extension. To address this issue, some alternatives have been proposed, such as the use of diesel generators or on-site electricity production with renewable energy sources. The former, despite the relatively low initial investment, presents some difficulties associated with fuel transporta- tion logistics, sensitivity to oil price fluctuations, and high life cycle cost. Renewable energy sources, in this case, seem to be the most appropriate, constituting not only a less expensive option (when the whole life cycle cost is taken into account), but also a more environ- mental friendly solution. The fact that it avoids the logistics of fuel transportation is a feature that reduces not only financial costs, but also simplifies the project by being more dependent on on-site resources. Moreover, the renewable energy systems usually have decreasing costs as the technologies become more widespread. Unlike other countries where renewable energy systems are do- nated or commercialized by NGOs and other entities, in Brazil they are currently installed mainly with funds from the Brazilian government through its electrification program called Luz para Todos (Light for All). As the grid extension reaches its feasible limit, alternative solutions for the supply of small isolated communities become more important in rural electrification. The utilities have experienced high grid extension costs [5,6], and in many cases grid extension is not feasible at all. In this context, photovoltaic (PV) systems are considered one of the main technologies for electrification of isolated sites as presented in [7]. It is already a mature technology, and although a lot of research on http://dx.doi.org/10.1016/j.rser.2017.05.016 Received 12 December 2016; Received in revised form 11 April 2017; Accepted 4 May 2017 ⁎ Corresponding author. E-mail addresses: robvaler@gmail.com (L.R. Valer), alex@iee.usp.br (A.R.A. Manito), tina@iee.usp.br (T.B.S. Ribeiro), zilles@iee.usp.br (R. Zilles), jtpinho@ufpa.br (J.T. Pinho). Renewable and Sustainable Energy Reviews 78 (2017) 1033–1043 1364-0321/ © 2017 Elsevier Ltd. All rights reserved. MARK