# Democratization of PV Micro-Generation System Monitoring Based on Narrowband-IoT
## 6 Conclusions  
The proliferation of PV installations either for self-consumption or with the aim of alleviating dependency on the grid is moving the energy system to more decentralized power generation. This new scenario allows users (who now are prosumers) to generate and/or consume their own energy. The lack of information about these PV systems emerge  
Figure 17: Comparison of PV module temperature vs. ambient temperature. Figure 18: Communication relative errors: Average daily values. as a relevant challenge for the management of micro- and medium-size grids, as the generation is more distributed. This paper describes a monitoring solution suitable to be applied for self-consumption or any other micro-generation installation, covering the installations of the so-called 'prosumers' and aiming to providing them with a tool that informs them about their local self-consumption. The proposed system allows us to monitor both electrical and environmental variables. A prototype was calibrated and successfully evaluated in a real PV self-consumption installation. Both current and voltage sensors were calibrated, determining 3% and 4% relative error, respectively, under laboratory conditions. The system includes a 6.5 W PV solar panel and a battery for energy requirements. Charge and discharge battery cycles were also monitored and included in the paper. Regarding the received data through NB-IoT communications versus inverter data, voltage and current have enough precision, 2.45% and 3.9%, respectively, to evaluate the operation of the plant with security. In addition, the proposed system provides a reliable connectivity with a packet delivery error around 4.6% and stable time interval between packets of 60 s. The size of the string was 37 bytes: 17 bytes of temporary fingerprint, 4 \(\times\) 5 floating bytes. This solution is also able to be implemented in large PV power plants, as well as other alternative renewable installations. Conceptualization, J.M.P.-P. and A.M.-G.; methodology, A.P.R.-G. and A.M.-A. ; software, R.J.-S. and D.C.-P.; formal analysis, [PERSON]-S. and J.M.P.-P.; resources, A.P.R. [PERSON] and [PERSON]; data curation, [PERSON] and [PERSON]; writing--original draft preparation, [PERSON] and [PERSON]; writing--review and editing, [PERSON] and [PERSON]; supervision, [PERSON] and [PERSON]. All authors have read and agreed to the published version of the manuscript. This work was partially supported by the Spanish agreement (2021) between the Institute for Development of the Region of Murcia (INFO) and the Technological Center for Energy and Environment (CETENMA). The paper includes results of the activity conducted under the 'Research Program for Groups of Scientific Excellence at Region of Murcia (Spain)' Project PVBRAIN (grant 2021.08.CT01.0035). A.P.R-G would like to thank European Commission Horizon Project PHOENIX (Project number: 893079). Not applicable. The data that support the findings of this study are available from the corresponding author, [PERSON], upon reasonable request. The authors declare no conflict of interest. The following abbreviations are used in this manuscript: \begin{tabular}{l l} CNC & Computer numerical control \\ DSO & Distribution System Operator \\ IEC & International Electrotechnical Commission \\ IoT & Internet-of-Things \\ NB & Narrow band \\ LPWAN & Low-power wireless area network \\ LTE & Long-Term Evolution \\ MAC & Media Access Control \\ PCB & Printed circuit board \\ PV & Photovoltaic \\ Quality of service & QoS \\ RES & Renewable Energy Sources \\ SET Plan & Strategic Energy Technology Plan \\ TSO & Transmission System Operator \\ \end{tabular}