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ENBifacial photovoltaic systems have become a mainstream technology in utility scale and complex PV projects. Their performance depends not only on irradiance incident on the front side of the modules, but also on reflected and diffuse irradiance reaching the rear side from the ground and surrounding surfaces. LuciSun provides technical advisory and advanced modelling services for bifacial PV projects, supporting feasibility studies, design optimisation, and risk-informed decision-making in contexts where simplified bifacial assumptions are no longer sufficient.
LuciSun delivers dedicated simulation studies for bifacial PV systems across a wide range of applications, including ground mounted plants, carports, vertical PV, building-integrated photovoltaics (BIPV), agrivoltaics, and sites with complex terrain or surroundings. These services have been delivered to a wide range of clients across multiple projects, covering utility scale installations and complex configurations where standard bifacial assumptions were not sufficient. The studies are carried out by LuciSun experts using LuSim as a core modelling tool to explicitly assess rear side irradiance, bifacial gains, and their sensitivity to design and environmental parameters.
Unlike monofacial systems, bifacial PV performance is strongly coupled to its environment. Ground properties, surrounding objects, terrain geometry, and shading conditions all influence the amount and distribution of irradiance reaching the rear side of the modules. Uniform bifacial gain factors or simplified albedo based corrections often fail to capture these interactions accurately, especially in non-ideal or heterogeneous environments. LuSim addresses this challenge through explicit 3D representation of geometry and materials.
LuSim evaluates rear side irradiance using the same physically consistent 3D framework applied to the front side of the modules. Reflected irradiance from the ground and surrounding surfaces is computed explicitly rather than approximated through empirical bifacial gain coefficients. The rear side of each module is discretised spatially, allowing irradiance contributions to vary locally across the module surface and over time, reflecting real spatial and temporal heterogeneity.
Ground reflectance plays a central role in bifacial PV performance, yet real installations rarely exhibit uniform albedo. Vegetation, soil conditions, gravel, concrete, snow, or dedicated reflective treatments can create strong spatial variability. Beyond simple Lambertian assumptions, the angular distribution of reflected light, commonly described through bidirectional reflectance distribution functions (BRDF), can influence rear side irradiance in specific configurations.
LuSim represents the ground explicitly in 3D and allows spatially varying material properties to be assigned. This makes it possible to analyse heterogeneous albedo distributions, partial treatments, and localised ground configurations and to assess their impact on bifacial gains consistently, while remaining compatible with different reflectance assumptions depending on project needs.
Beyond global albedo assumptions, bifacial PV design may involve the use of highly reflective ground treatments, such as white gravel or reflective membranes, applied only on specific areas of the site. LuSim enables the assessment of the position, extent, and geometry of such reflective surfaces relative to the PV rows, allowing LuciSun studies to determine where high reflectance materials are most effective in increasing rear side irradiance.
This type of analysis is applicable to both fixed structures and tracking systems, where the optimal placement of reflective surfaces depends on shading patterns, row spacing, and system geometry.
In bifacial systems, shading affects not only direct irradiance on the modules but also the reflected component by modifying which parts of the ground and surrounding surfaces are illuminated. Support structures, mounting elements, and nearby objects can significantly alter rear side irradiance distributions and introduce localised electrical mismatch. LuSim captures this interaction coherently by evaluating shading, illumination, and reflected irradiance within a single 3D framework, allowing rear side contributions to change consistently with geometry and solar position.
Rear side irradiance computed by LuSim is integrated directly into the PV energy yield modelling chain. Front and rear contributions are combined at the module level and converted into electrical power using validated photovoltaic performance models. Spatially resolved rear side irradiance enables consistent assessment of bifacial gains alongside electrical behaviour, mismatch effects, and system losses, supporting robust energy yield assessments without relying on fixed bifacial assumptions.
The bifacial modelling approaches implemented in LuSim have been applied and validated in industrial studies and research projects, including large scale utility PV plants, carports, agrivoltaic systems, and European research initiatives such as SERENDI-PV and dedicated bifacial PV research projects. These applications have supported comparative analyses, sensitivity studies, and discussions of modelling uncertainty under real project conditions.
Accurate bifacial PV modelling is not only a design optimisation issue, but also a prerequisite for robust uncertainty assessment and bankability analysis. Small changes in geometry, ground treatment, or shading configuration can lead to significant differences in bifacial gains and overall energy yield. LuciSun’s bifacial PV advisory services provide a physically consistent and spatially resolved basis to compare design options, assess risks, and support informed technical and financial decision-making in complex bifacial PV projects.
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