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There is an increasing interest in Floating PV (FPV) plants thanks to their advantages compared with ground and rooftop PV systems, mainly related to very limited land use, evaporation reduction, and improvement of the energy performance. The PV modules installed on water surfaces have a natural cooling due to the microclimate in which they operate, which reduces thermal power losses. Furthermore, they can be equipped with simple and effective forced active water cooling systems which further improve FPVs performance. The objective of this study is to develop and validate mathematical models capable of estimating the performance of bifacial and monofacial PV modules installed on water surfaces. Starting from the energy balances of the PV modules, different scenarios are simulated, such as mono and bifacial systems installed on the rooftop, mono, and bifacial FPV systems in presence of natural (or passive) and forced (or active) cooling. The models are validated against experimental data acquired in FPV systems installed in the Enel Innovation Lab by Enel Green Power, Catania (Italy). The obtained results show an energy gain due to bifaciality of 5.24%. The passive cooling in the FPV increases the energy collected by 3% (maximum obtainable of 6.4%) and 2.6% for the bifacial and monofacial technology respectively. Active cooling in FPVs increases the collected energy by 9.7% (maximum achievable of 13.5%) and 9.5% for the bifacial and monofacial respectively. • Thermal behaviour of monofacial and bifacial FPV systems is studied. • Models to estimate the temperature of the PV modules with passive and active cooling are presented. [ABSTRACT FROM AUTHOR]

DC/DC converters are widely used in photovoltaic (PV) systems to track the maximum power points (MPP) of a photovoltaic generator (PVG). The variation of solar radiation (G) and PV cells temperature (T) affect the power efficiency of these DC/DC converters because they change the MPP, thus a sizing adaptation of the component values in these DC/DC converters is needed. Power loss in the inductor due to core saturation can severely degrade power efficiency. This paper proposes a new method that allows to adapt the inductor values according to the variable output power of the PV array in order to minimize losses and improve the converter power efficiency. The main idea is to replace the DC/DC inductor with a coupled inductor where the DC/DC inductor value is adjusted through an additional winding in the magnetic core that modulates the magnetic field inside it. Low current intensities from the PVG supply this winding through a circuit controlled by a fuzzy logic controller in order to regulate the second winding current intensity. Experimental results show a significant improvement of the power efficiency of the proposed solution as compared to a conventional converter. [ABSTRACT FROM AUTHOR]

The photovoltaic geographic potential (PVGP) is defined as the fraction of the solar irradiation received on the land available for a photovoltaic facility. The area of this usable land is calculated by a suitability factor which is determined by a variety of different geographical constraints. We extend this kind of analysis to floating photovoltaic (FPV) structures and consider the use of water surfaces with the same definitions and notations used to define the PVGP for systems installed on the ground. Results are very promising because of the large water surfaces available and because of the possibility to build floating structures which are more compact than land based photovoltaic plants. In fact, using just 1% of natural basins areas to install FPV plants, about 25% of the world electrical energy demand (in 2014) can be supplied. The PVGP is evaluated for two PVF raft geometries: one is a typical shed structure, the other is an innovative solution named gable. [ABSTRACT FROM AUTHOR]

The aim of this study is to analyze the different decentralized voltage control strategies, based on the reactive power control of photovoltaic inverters. The study focuses on evaluating their impact in terms of reactive power demanded from the grid, due to the regulation, and active losses in the network and in the photovoltaic inverters. In a second step, the presence of battery energy storage systems in the network is considered and further analysis are performed, in order to take into account the overvoltage mitigation by peak shaving of the photovoltaic generation. All the simulations are performed in MATLAB/SIMULINK, where the model of a single-phase low-voltage distribution network with distributed generation sources is implemented. [ABSTRACT FROM AUTHOR]

The climate conditions can affect the accuracy of photovoltaic (PV) system performance models that can be used for monitoring and diagnostic purposes. In this paper, an improved energetic physical model has been considered to estimate the power production of PV systems. Specifically, in this model, special attention has been devoted to the modeling of optical losses (IAM losses) and to the inverter efficiency under low-power conditions. A comparative analysis of the proposed model applied to two PV plants installed respectively in the north of Denmark (Aalborg) and in the south of Italy (Agrigento) has been performed. The different ambient, operating and installation conditions allow to understand how these factors impact the precision and effectiveness of such model. The experimental results show that the proposed model allows us to have a good estimation of AC power in terms of Relative Mean Bias Error, normalized Root-Mean-Square Error, and the Correlation Coefficient. Further in order to have the possibility to analyze and compare the performance of the studied PV plants with others, the efficiency of the systems has been estimated by both Performance Ratio and Corrected Performance Ratio. [ABSTRACT FROM AUTHOR]

To ensure the cost effectiveness of photovoltaic power plants (PVPPs) it is needed to keep the level of yearly energy production as high as possible. In this context, efficiency and availability of a PVPP have to be checked continuously. The section of a PVPP which deserves more attention is surely the PV array, where many fault conditions can happen (shading, by-pass diode faults, cable interruptions, and so on). A diagnostic tool to detect faults in the PV array is desirable, even if its implementation is critical owing to: the fluctuation of the operating conditions (mainly irradiance), which complicates the instantaneous response investigation and costs and implementation constraints to implement a distributed (at PV module level) or semi-distributed (at string level) monitoring/diagnostic system. Particularly, for BIPV systems, further constraints related to the regular access for inspection and maintenance operations have to be considered. In this paper, the procedure adopted to develop and validate a diagnostic tool can be summarized in four steps: (1) using real data to model the PV array; (2) introducing several fault scenarios on the real PV string and analyzing the relative modifications of the I – V curves; (3) assessment of the meaningful parameters useful to discern the different faults by means of a PV generator (PVG) simulator based on a metaheuristic technique denominated ABC-DE ; (4) proposition of several fault signing tables to assess the PV plant fault diagnostic. [ABSTRACT FROM AUTHOR]

Floating Photovoltaic (FPV) is an emerging technology that has experienced significant growth in the renewable energy market since 2016. It is estimated that technical improvements along with governmental initiatives will promote the growth rate of this technology over 31% in 2024. This study comprehensively reviews the floating photovoltaic (FPV) solar energy conversion technology by deep investigating the technical advancements and presenting a deliberate discussion on the comparison between floating and ground-mounted photovoltaic (PV) systems. Also, the economics and environmental impacts of FPV plants are presented by introducing the main challenges and prospects. The FPV plants can be conventionally installed on water bodies/dam reservoirs or be implemented as multipurpose systems to produce simultaneous food and power. Installing FPV modules over water reservoirs can prevent evaporation but penetration of solar radiation still remains an issue that can be eliminated by employing bifacial PV modules. The salt deposition in off-shore plants and algae-bloom growth are other important issues that can degrade modules over time and adversely affect the aquatic ecosystem. The capital expenditure (CAPEX) for FPV systems is about 25% higher than ground-mounted plants, mainly due to the existence of floats, moorings, and anchors. It has been stated that the capacity increase of FPV plants (ranges from 52 kW to 2 MW) can intensely decrease the levelized cost of energy (LCOE) up to 85%. It is estimated that FPV technology can become more affordable in the future by further research, developments, and progress in both technology and materials. [ABSTRACT FROM AUTHOR]