Renewable solar energy has been increasingly used due to its efficiency and cleanliness. Integrating solar cells directly to supporting structures can eliminate the mounting systems and reduce the cost. Once integrated, the strains of solar cells and supporting materials become the same. Therefore, it is necessary to study the strain effect on the solar cells. This study evaluates the performance of amorphous silicon solar cells (a-Si) when they are integrated with b. Renewable solar energy has been increasingly used due to its efficiency and cleanliness. Integrating solar cells directly to supporting structures can eliminate the mounting systems and reduce the cost. Once integrated, the strains of solar cells and supporting materials become the same. Therefore, it is necessary to study the strain effect on the solar cells. This study evaluates the performance of amorphous silicon solar cells (a-Si) when they are integrated with building substrates, such as roofs and exterior walls. Based on the materials used and the failure modes under compression, these building substrates can be generally categorized into two groups: rigid and flexible substrates, which are simulated using concrete/FRP-wrapped concrete, and thin FRP plate attached to rubber, respectively, in this study. Cylinders from different materials were fabricated and bonded with (a-Si) solar cells, and then tested under compression. During the test, the (a-Si) solar cells were illuminated using a projector to simulate the sun light. J-V characteristics curves were measured and Maximum Power Point (MPP) was calculated. It is observed that the performance of (a-Si) solar cells remained unchanged until failure for specimens with rigid substrates; and buckling of solar cells, including both local and global buckling, occurred for specimens with flexible substrate. It can be concluded that, while the strain has negligible effect on the performance of (a-Si) solar cells under pure compression because of their small deflections, it has a signif. ••Strain effect on the performance of amorphous silicon solar cells attached to rigid and flexible substrates.••The rigid substrate includes concrete and FRP-wrapped concrete, and the flexible substrate includes rubber.••Strain has negligible effect on solar cells under pure compression when attached to rigid substrates.••Strain has a significant effect on solar cells under buckling when attached to flexible substrate.PerformanceSolar cellRigid substrateFlexible substrateSolar energy is clean and efficient. It has been widely used, especially in the area where electricity grid is not accessible. In the US, the Solar Investment Tax Credit (ITC) has successfully pushed hardware prices down and installer experience up. Although the price of the module will continue to decrease, there is little room for substantial reduction. Therefore, more efficient ways are required to optimize the cost, such as eliminating the mounting system. Once the supporting system is eliminated, solar cells become an integral part of the supporting structures. Accordingly, they are subjected to the same strains as those of the supporting structures, which are caused by different types of load, such as gravity, wind, seismic loads, etc. Therefore, it is necessary to study the performance of solar cells under different strain states with different supporting structures.The focus of this study is to evaluate amorphous silicon solar cells (a-Si) solar cells integrated with buildings roofs and exterior walls. (A-Si) solar cell is a thin-film solar cell that can achieve an efficiency of about 14%. It is flexible and works properly under bending. Therefore, it is selected for this study. Different materials can be used as supporting materials, including concrete and Fiber-Reinforced Polymer (FRP). Concrete is one of the mostly widely used construction materials. In recent years, FRP has been increasingly used for b. 2.1. Test programAs described above, (a-Si) solar cells were attached to both rigid and flexible substrates. The rigid substrate included normal concrete and FRP-wrapped concrete, which was intended to introduce pure compression failure. The flexible substrate included thin FRP plate attached to rubber cylinder. It is noted that neoprene rubber is rarely used as building material. However, it can be used to control the buckling shape of the attached thin FRP plate using simple test setup in the laboratory. Therefore, it is adopted to introduce the buckling of flexible substrate. The test program is shown in Fig. 1. Properties for (a-Si) solar cell and other materials are provided below.2.3. Specimen fabricationConcrete cylinders were 203 mm (8 in.) high and 102 mm (4 in.) in diameter, and rubber cylinders were 152 mm (6 in.) high and 76 mm (3 in.) in diameter. For concrete cylinders wrapped with FRP, (a-Si) solar cells were attached to FRP during the fabrication process. For normal concrete, (a-Si) solar cells were directly attached to concrete. For rubber cylinders, (a-Si) solar cells were either directly bonded to rubber or thin FRP plates that were attached to rubber at th.
