Floating photovoltaic (FPV) systems are emerging as a promising solution to the scarcity of suitable land for ground-mounted solar PV (GPV) installations. By the end of 2022, global FPV capacity reached 5.7 GWp following a remarkable compound annual growth rate of approximately 87.5% from 2015 to 2022. This growth introduces a significant new frontier for operation and maintenance (O&M) practices in the solar industry. As the industry matures and more FPV assets come under operation, the need for innovative, efficient, and environmentally sensitive O&M strategies becomes imperative. This review presents the existing information on the O&M of FPV systems, highlighting the unique challenges and opportunities that set FPV systems apart from conventional GPV installations. Through an examination of recent advancements, best practices, and areas requiring further research, this study aims to provide valuable insights for optimizing the performance and sustainability of FPV systems.

In this work we demonstrate the angular color stability of textured c-Si substrates colored by single layer thin film coatings of ${\mathrm{SiN}}_x$ . These coatings show higher angular color stability on substrates with a random upright pyramidal surface texture compared to identical coatings on planar silicon substrates. Angle dependent reflectance measurements, supported by a modeling framework, display that the reflectance peaks originating from thin film interference of coated textured substrates only shift about 15 nm with an increasing angle of incidence from ${10}^{°}$ to ${80}^{°}$ , while the reflectance peaks of planar substrates with identical coatings shift about 120 nm at these angles. More specifically, reflectance peaks of planar substrates shift to shorter wavelengths, leading to a blue shift of the color appearance. The stable peak position of the textured samples is explained by a 2D representation of their surface texture and the primarily double interference interaction on it. While it is well known that a wide range of colors can be realized exhibiting low optical losses with thin film coatings, angular color stability was often not taken into account. However, for building integrated photovoltaics applications, a high angular color stability is desired, underlining the importance of using these textures. In most installed c-Si photovoltaics, similar substrate surface textures and dielectric thin film layers are already used. Therefore, this work envisions a route to facilitate large scale production of colored solar cells on textured c-Si substrates, colored by thin film ${\mathrm{SiN}}_x$ layers, with minimized optical losses and improved angular color stability.

Moisture ingress into photovoltaic (PV) modules is one of the main drivers behind module midlife- and wear-out-failures, particularly when modules are installed in locations with high humidity stress. To minimize moisture ingress, impermeable front- and backsheets in combination with an edge sealant around the module perimeter can be used. Besides low water vapor transmission rates through the sealant material, mechanical durability of the sealant is of utmost importance. In this work, we assess the durability of a double edge sealant design used in a floating PV (FPV) concept in which the float and PV module are integrated. Strength of attachment testing, combined with measurements of failure type, are performed on samples taken from an FPV prototype after outdoor exposure and are compared to measurements on lab samples that are unexposed or exposed to indoor accelerated stress. We observe a significant decrease of lap shear strength for the double edge sealant after field exposure, coupled with more adhesive failure. Correlation to accelerated stress test results indicates that the observed adhesion losses can partly be attributed to degradation driven by ultraviolet light. By reporting on observations of FPV field degradation and exploring how indoor accelerated stress testing can be used to understand the origins of the observed degradation, this work constitutes an important early contribution to the field of FPV reliability.

The degradation of solar photovoltaic (PV) modules over time, which are aggravated by defects, significantly affects the performance of utility-scale PV parks. This study presents a quantitative assessment of the power loss from module defects and evaluates the cost-effectiveness of replacing defective modules at various stages of degradation. A module test site was established in Norway with six different defects, and continuous thermographic monitoring, combined with light IV measurements and electroluminescence (EL) imaging, provides partial support for further calculations on the long-term effects of the defects. The cumulative module energy loss is calculated over a 25-year park lifespan under both Norwegian and Chilean environmental conditions, with the latter representing higher solar irradiation levels. The energy gain from replacing the defective modules at various stages of degradation is compared to the costs of replacement, both for infant-life failures and mid-life failures. It is likely not beneficial to replace minor infant-life defects of 1% power loss in low-irradiation regions like Norway. For Chilean conditions, it can be cost-effective, but primarily if the module is replaced around mid park life, which gives a larger yield when replaced with a new module. For more severe defects of 10% loss, the replacement gain is above the replacement cost for high-irradiation locations, and replacing the 33% power loss defect is cost-effective for both locations, even when discovered late in the park lifetime. It is primarily beneficial to replace mid-life defects in high-irradiation locations.