As PV deployment diversifies beyond open-field ground-mounted arrays, a new report from IEA PVPS Task 13 argues that the industry needs to rethink how it designs, tests and qualifies PV systems built into buildings, floated on water, and shared with farmland. “Optimisation of Photovoltaic Systems for Different Applications” (Report IEA-PVPS T13-39:2026) is a follow-up to Task 13’s earlier work on climate-specific PV optimisation (IEA-PVPS T13-32:2025), shifting the focus to application-specific considerations.
The report’s central argument is straightforward: building-integrated PV (BIPV), floating PV (FPV) and agrivoltaics (AV) are not just PV systems installed in unusual places. They are multifunctional infrastructure, and their assessment therefore needs to extend beyond conventional techno-economic metrics such as performance ratio and LCOE. For this reason, the report discusses application-specific KPIs across four categories: energy, economic, environmental and social performance.
For building-integrated systems, the report highlights that operating temperature depends a lot on the configuration, and that it is often overstated as a universal risk. Field data from SUPSI in Switzerland, representative of moderate climates, found that only fully insulated, unventilated roof BIPV configurations reached temperatures high enough to trigger the elevated-temperature qualification testing specified in IEC TS 63126:2020. Partially ventilated roofs and façades stayed within standard thresholds. That’s a useful data point for developers debating whether premium high-temperature-rated modules are actually necessary for a given mounting configuration depending on climate.
Partial shading gets equal billing as a structural risk, not just a yield loss. Because BIPV modules sit among chimneys, trees and neighbouring buildings, shading is frequent and unpredictable, and the report catalogues concrete mitigation paths: finer bypass-diode segmentation, back-contact cells with lower breakdown voltages, and module-level power electronics. Careful system design, including the appropriate selection and implementation of shading-mitigation measures, plays a key role in reducing both performance losses and reliability risks associated with partial shading. It also cautions that “shade-tolerant” remains an undefined, manufacturer-specific marketing term with no standardised test.
Two case studies — a 368 kWp coloured façade in Amsterdam and Vienna’s Floridsdorf metro station — illustrate the aesthetic-performance trade-off in practice, including the finding that structural (interference-based) colouration losses run 5–20%, versus 20–50% for absorbing pigments.
For FPV, the report highlights how strongly thermal behaviour depends on system configuration and local conditions. The assumption that proximity to water in FPV automatically means cooler, higher-yielding modules is not necessarily true. The cooling effect depends on factors like system design as well as on the presence of surrounding buildings or vegetation that can obstruct wind.
Beyond thermal performance, the report also examines the mechanical stresses associated with FPV. Wave-flume experiments show that modules can be exposed to substantial pressures and loads from breaking waves without visible damage, although the results depend on the platform and mounting configuration. Maintenance access introduces another design challenge: simulations indicate that modules fully supported by the water beneath a floating membrane may tolerate a person stepping on them, but localised and dynamic loads can still cause damage.
Two case studies are presented as a practical reminder for anyone designing, operating and modelling FPV systems. In the Catania case study, simulations with PVsyst and SAM show how the choice of modelling tool and its underlying assumptions, such as the thermal model, can affect FPV performance estimates. The second example shows that a recent FPV plant installed at 1,810 m in the Swiss Alps delivered a 29.1% production gain over an equivalent non-alpine plant thanks to high-altitude conditions such as snow albedo and lower operating temperatures. However, heavy snow accumulation, ice and seasonal transitions between floating and grounded operation pose significant structural and operational challenges.
The report discusses several durability and operational risks of AV, beyond the now-familiar shading and land-use-efficiency. One is ammonia exposure from fertilisers and livestock farming. Laboratory and field data show ammonia diffusing rapidly through EVA encapsulants and PET backsheets, especially under humid conditions, corroding aluminium frames, degrading adhesives, and in one documented case causing junction-box arcing above a livestock exhaust outlet. Mitigations include double-glass modules, ammonia-stable adhesives and sealants, and physical distance from high-emission zones.
Soiling in AV systems also behaves differently than in conventional plants. A study in Chile recorded a maximum soiling loss of 30.2% on a module that was never cleaned, while research in Germany found transmittance losses ranging from 0.1% to 47%, with considerable variation among system configurations and samples. Agricultural machinery can increase contamination, especially on the rear surface of the modules, and deposits may adhere more strongly and be less effectively removed by rainfall.
Case studies at Solvallen in Sweden and Flakkebjerg in Denmark are presented to discuss actual operational challenges. At Solvallen, several modules in a fixed vertical bifacial system developed glass fractures, potentially linked to non-uniform foundation movement during freeze–thaw cycles, even if investigations are ongoing. At Flakkebjerg, autonomous agricultural robots experienced unstable GPS signals when operating beneath the steel tracker structures.
Across all three applications, the report’s throughline is the same: standard IEC 61853 energy-rating and qualification protocols, built for open-rack ground-mounted systems, apply only partially to integrated PV and require adaptation to properly capture actual conditions. Revisions are already in progress for solutions like rooftops, façades and some configurations relevant to AV, but further adaptations are still needed. For developers and asset managers, the practical takeaway is to account for application-specific energy, economic, environmental and social requirements from the earliest stages of project development.
Author: Ignacio Landivar
IEA PVPS Task 13 aims at supporting the solar industry in overcoming challenges and leveraging the full potential of bifacial tracking through ongoing research, international collaboration, and dissemination of research findings.
This article is part of a monthly column by the IEA PVPS programme. It was contributed by IEA PVPS Task 13 – Reliability and Performance of PV Systems.
The views and opinions expressed in this article are the author’s own, and do not necessarily reflect those held by pv magazine.
This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: [email protected].
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