A prevailing assumption in the solar industry — that floating photovoltaic installations are inherently more vulnerable to moisture-related degradation than their land-based equivalents — is being challenged by new research findings.

Rethinking Humidity Risk for Water-Based Solar

Studies of floating PV systems, which are mounted on bodies of water such as reservoirs and lakes, have long prompted concerns that proximity to a water surface would expose panels to elevated humidity levels, accelerating stress and potential damage to module components. However, researchers have found that this is not necessarily the case. Floating PV arrays do not automatically face greater humidity-induced stress compared to conventional ground-mounted systems, according to the findings.

Climate and Design as Dominant Factors

The research points to climate conditions and system design as variables that often carry more weight than the simple fact of being situated over water. In other words, a floating installation in an arid or semi-arid environment, or one designed with adequate ventilation and moisture management, may encounter humidity stress levels comparable to — or even lower than — a ground-mounted system located in a more persistently humid terrestrial setting. This finding suggests that blanket assumptions about floating PV and moisture risk may need to be revisited by developers, engineers, and asset managers evaluating long-term system reliability.

Implications for System Planning and Reliability Assessment

The distinction matters for project planning and bankability analysis. If humidity stress in floating PV systems is not inherently higher than in ground-mounted arrays, then the risk models and maintenance schedules applied to water-based installations may need to be calibrated more carefully to site-specific climate data rather than defaulting to elevated risk assumptions based solely on installation type. System design choices — which the researchers identified as a key factor — may offer meaningful opportunities to mitigate moisture-related degradation regardless of whether panels are deployed over land or water.

Floating PV has expanded steadily as a technology category, valued for its ability to generate power without consuming agricultural or developable land, while also offering secondary benefits such as reducing evaporation from reservoirs. As the sector matures, a more nuanced understanding of the environmental stresses these systems actually face, rather than those assumed by analogy, becomes increasingly relevant to accurate performance modeling and long-term operational planning.