# Floating Photovoltaic Plant Monitoring: A Review of Requirements and Feasible Technologies
## 8 Conclusions  
Floating PV is an emerging technology that can help the sustainable diffusion of photovoltaic energy by exploiting poorly used areas and reducing the requirement of areas more suitable for other uses, such as, for example, agricultural ones. However, even the involvement of large areas of inland or sea basins can lead to an environmental impact that has been so far poorly evaluated at an experimental level. The extensive technical literature examined in this review highlights, however, first and foremost that there is no organic effort to monitor this impact to date, but that, on the contrary, FPV probably urgently requires the definition of general rules and criteria that photovoltaic plants should adopt both in implementation and operational management. As regards strictly the object of this work, the literature of the sector is mainly related to photovoltaic systems built on internal basins. For these, the general recommendation is not to exceed coverage factors, equal to 50% of the available basin surface, and to monitor a series of chemical-physical parameters: submarine light intensity, Chlorophyll-a, turbidity, pH, water electric conductivity, dissolved oxygen, and temperature, both immediately below the plant and in points sufficiently away from it. There are no data related to how many of these points there should be nor how deep the column of water examined in each of them should be (and, therefore, how many samples should be examined for each column). We can obviously assume, as a starting hypothesis, that the points to be sampled are directly proportional to the extension of the FPV system, but at present, there are no specific works addressing this problem, not even from a purely modeling point of view. In any case, monitoring must be carried out both before the installation of the system and during its operational life, with a periodicity such as to be able to reliably evaluate the environmental impact of the system itself. In addition to the standard parameters to be monitored for any photovoltaic system, floating systems require the monitoring of a series of additional parameters, which are very similar to those typical of any vessel. These parameters are in fact also essential for the study and the evaluation of the environmental impact of a floating photovoltaic system because they allow a more reliable correlation of the parameters detected with the actual state of the PV system itself. As regards the water monitoring technologies most suitable for this purpose, the review highlights the need for ad hoc solutions that can positively exploit the existing compromise between the cost of the detection units, their number, and the profiles and the width of the area to be monitored. The choice is between solutions based on multiparametric probes managed by specialized personnel and means, or through completely mobile systems or even autonomous units such as ASV/AUV solutions. Again, there are not enough data to make a choice. However, while the first solution certainly involves a broader and more complex use of specialized personnel, the second minimizes human intervention, and could also more easily adapt, in theory, to operational contexts, such as, for example, off-shore ones, where the use of unmanned solutions is also preferable for security reasons. For robotic agents, various technical solutions underlying innovative sampling technologies were therefore reviewed with the aim of presenting their strengths and weaknesses in different operational scenarios. This review paper highlights the need for a standardized approach to water quality management (WQM) in relation to floating photovoltaic (FPV) systems.