**6. Conclusions**

This paper presents a complete analysis on the real benefits introduced by a DRS system in a PV plant after a considerable power reduction. In particular, in order to evaluate the overall economic impact on the costs of a PV plant the technical and economic aspects about the DRS have been considered. In the first part of the paper an economic analysis of different DRSs due to the costs of the components and to the adopted topological schemes, is carried out. Switching matrix, sensing network and driving circuit constitute the architecture of DRS, the choice of switches and their number affects the electrical endurance. A more flexible DRS involves higher initial cost due to the number of switches required by the adopted architecture, but at the same time a less exploitation and therefore a longer useful life.

From the economic point of view, the analysis has been extended to different countries of EU in order to considerate incentives policies, location of installation and lifestyles of the people, while, from a technical study, that takes into account the hardware complexity in terms of the components required and other technical aspects, the costs and lifetime of four DRS have been estimated. The economic tool used in this analysis is the NPV and the payback time.

Firstly, in all scenarios the analysis has demonstrated the positive economic impact on the use of a DRS in a PV plant with respect to the cases without DRS. The best results have been obtained in Spain thanks to the higher value of the incentives per year in terms of NPV and payback time, whereas good results have been obtained for Italy, Bulgaria and Greece. The worst results have been obtained for France and Germany due to the lower values of the production facility. Among the DRS considered in the economic analysis, the DRS4 option allows one to obtain the best results in all cases. The best performance of DRS4 is attributable to the high number of switches that allows it to increase the lifetime of the system.

**Author Contributions:** Conceptualization, F.V.; methodology, F.V. and P.R.; software, G.S. and F.P.; validation, F.P. and G.S.; formal analysis, F.V. and G.S.; investigation, P.R. and F.V.; resources, R.M. and G.A.; data curation, G.S. and F.P.; writing—original draft preparation, F.P., G.S., and F.V.; writing—review and editing, G.A. and F.V.; visualization, G.A. and R.M.; supervision, G.A., R.M. and F.V. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding. This work was financially supported by MIUR-Ministero dell'Istruzione, dell'Università e della Ricerca (Italian Ministry of Education, University and Research) and by SDESLab (Sustainable Development and Energy Saving Laboratory) and LEAP (Laboratory of Electrical APplications) of the University of Palermo.

**Conflicts of Interest:** The authors declare no conflict of interest.
