Open -source technologies and IoT as a tool for meeting the challenge of mass-scale Solar Home Systems monitoring in developing countries - Lopez-Vargas A; Fuentes M; Vivar M (2018 Ieee 7th World Conference On Photovoltaic Energy Conversion, Wcpec 2018 - A Joint Conference Of 45th Ieee Pvsc, 28th Pvsec And 34th Eu Pvsec, 2018)