International Energy Agency: Enhancing the Prospects of Photovoltaic Glass in BIPV

To promote the adoption of Building Integrated Photovoltaics (BIPV) as a more readily accepted glass material, a task group of the International Energy Agency's Photovoltaic Power Systems Programme (IEA - PVPS) has addressedBIPVSolar Heat Gain Coefficient(SHGC)calculation issues. This is part ofIEA PVPSTask15international standardization work.

This is a global project aimed at addressing barriers associated with Building Integrated Photovoltaics (BIPV). The task’s newly released report provides an experimental approach to determine the solar heat gain coefficient (SHGCalso known as“gvalue”), and how relevant standards should be modified to accommodatethe calculation of this coefficient in products.BIPVFurther Reading:Green Building New Favorite: In-depth Analysis of the Heat Transfer Coefficient of Cadmium Telluride Solar CellsThe solar heat gain coefficient is commonly used to quantify how much incident solar radiation is directly or indirectly converted into heat by building envelope components. Since photovoltaic generation reduces the solar energy that would otherwise be transferred to the interior as heat, adjustments are needed forits calculation method.BIPVTask team said:15“Understanding this impact is crucial for optimizing building energy efficiency, reducing cooling demands and promotingwider adoption of the solution.BIPVThe report, titled 'Solar Heat Gain Coefficient of Building-Integrated Photovoltaic Modules for Power Generation Facades,' focuses on the solar heat gain coefficient. The solar heat gain coefficient is a key indicator for calculating building cooling needs in traditional building glass. The report proposes two complementary methods. One method adjusts the calorimetric measurement method of the internationally standardized solar heat gain coefficient. The solar heat gain coefficient varies with the photovoltaic cell coverage ratio and the thermal properties of the glass, and the situation during power generation and power extraction during the measurement must also be considered. Another method is to calculate its solar heat gain coefficient based on”), and how relevant standards should be modified to accommodatethe optical and thermal properties of the glass component and the photovoltaic conversion efficiency of the component. This method adapts the international standard for traditional glass to accommodateBIPVtypical characteristics such as optical non-uniformity caused by solar cell coverage and power generation. These two proposals are the results of normative preliminary research conducted by members of TaskBIPVand recently published in the journal Energy and Buildings, namely: 'Component-Based Determination of Glass Solar Heat Gain Coefficient for Product Comparison', and 'International Inter-laboratory Comparison of Solar Heat Gain Coefficient of Building-Integrated Photovoltaic Modules15——BIPVResults of tests with and without power generation and different photovoltaic cell coverage ratios'. At the same time, modification suggestions for international standards based on research results have been proposed and are currently in the public consultation stage. The team said:These modifications improvethe comparability and accuracy of the solar heat gain coefficient assessment of glass units.Understanding this impact is crucial for optimizing building energy efficiency, reducing cooling demands and promoting这些修改提高了BIPV玻璃单元太阳得热系数评估的可比性和准确性。”), and how relevant standards should be modified to accommodate