The effect of soiling in flat PV modules has been already studied, causing a reduction of the electrical output of 4% on average. For CPV’s, as far as soiling produces light scattering at the optical collector surface, the scattered rays should be definitively lost because they cannot be focused onto the receivers again. While the theoretical study becomes difficult because soiling is variable at different sites, it becomes easier to begin the monitoring of the real field performance of concentrators and then raise the following question: how much does the soiling affect to PV concentrators in comparison with flat panels?’ The answers allow to predict the PV concentrator electrical performance and to establish a pattern of cleaning frequency. Some experiments have been conducted at the IES-UPM and CSES-ANU sites, consisting in linear reflective concentration systems, a point focus refractive concentrator and a flat module. All the systems have been measured when soiled and then after cleaning, achieving different increases of I SC . In general, results show that CPV systems are more sensitive to soiling than flat panels, accumulating losses in I SC of about 14% on average in three different tests conducted at IES-UPM and CSES-ANU test sites in Madrid (Spain) and Canberra (Australia). Some concentrators can reach losses up to 26% when the system is soiled for 4 months of exposure.

A novel datalogger based on free software and hardware has been designed, built, programmed and installed as an experimental prototype in multiple sites. Remote monitoring extends the effectiveness of the datalogger in areas deprived of electrical grid and traditional wired telecommunication networks. The integration of Internet of Things (IoT) in solar measurement systems allows the remote monitoring of small stand-alone photovoltaic (PV) systems, enhancing the performance and the maintenance of the system. The datalogger measured electric and climatic parameters (up to 14 parameters, expandable) with the required accuracy established by the IEC61724 standard; to include 3G technology in it allowed the stand-alone PV systems system monitoring remotely via web or via mobile application, all at low cost. An outdoor campaign of over 12 months under the harsh environmental conditions at multiple locations was performed to test the new datalogger under real and different conditions demonstrating the robustness and the reliability of the system.

Internet of Things (IoT) makes a significant contribution to development in economical, social and ecological terms. In this work, the current context to successfully apply IoT in developing countries to achieve the Sustainable Development Goals (SDGs) of United Nations is studied. Potential and opportunities of the IoT in the developing world as well as the current challenges of IoT in developing countries are reviewed. The research methodology is focused on the IoT context in the developing world as well as profitable IoT projects carried out in developing countries, using the SDGs as a reference. Key features as a technical challenges, environmental conditions or social differences are studied to contextualize IoT in developing countries. Finally, the combination of low-cost IoT and pay-as-you-go is presented as the best scenario to better disseminate the Internet of Things for Development (IoT4D) to achieve the Sustainable Development Goals by 2030.