Trends in Solar and Module Efficiency: The Future of Solar Cell and Module Technology
Solar module technology is rapidly evolving to increase efficiency, reduce costs, and expand into new application-specific form factors. One trend is the integration of emerging materials like perovskites. Perovskite solar cells have reached laboratory-cell efficiencies that compete with those of c-Si cells, and if certain challenges are resolved, this technology could mature as an alternative to mainstream cell technology.
Another trend is the implementation of tandem architectures, which can produce more electricity by minimizing energy losses. Tandem cells are made by stacking multiple solar cells on top of each other to form a tandem cell. Each subcell then collects a different part of the incident light so electricity is converted more efficiently. Tandems made of multiple III-V cells have long had world-record efficiency, but making large-area, low-cost tandem modules will require new designs, material combinations, and manufacturing techniques.
In addition to perovskites and tandem architectures, there are other technology trends to watch for in solar modules. One is the expected increase in module size and improved efficiency. Commercial CdTe modules reached 19% efficiency in 2021, and efficiency improvements have resulted, and are expected to continue, from adjustments to the CdTe module’s complex stack of materials and the processes for depositing and treating them.
Another trend is the use of application-specific form factors, which can improve efficiency by reducing inactive area. Inactive area does not directly produce electricity and includes borders, gaps between cells, metallization, and interconnection. Larger modules reduce the area fraction that is occupied by borders. Gaps between cells can be reduced through improved assembly precision or by adopting seamless or overlapping interconnection technology. Special interconnection and packaging materials can counteract the effects of inactive area, trapping more light in the module and increasing module efficiency.
Overall, the future of solar module technology is bright, with continued advancements in efficiency, size, and material combinations. These advancements will make solar energy even more competitive with traditional energy sources, and accelerate the adoption of solar energy around the world.
- Integration of emerging materials like perovskites: This trend involves the use of new materials such as perovskites in the fabrication of solar cells. Perovskite solar cells are a type of thin-film solar cell that has the potential to achieve high efficiency and low cost. Researchers have achieved laboratory efficiencies of over 25% with perovskite solar cells, and they are continuing to work on improving the stability and durability of these materials for commercial applications.
- Implementation of tandem architectures: This trend involves the stacking of multiple solar cells on top of each other to form a tandem cell. Each subcell collects a different part of the incident light, resulting in more efficient energy conversion. Tandem architectures can be made from different types of solar cells, including those made from silicon, III-V materials, or perovskites. Tandem solar cells have achieved world-record efficiencies, and this trend is expected to continue as researchers develop new designs, material combinations, and manufacturing techniques to make large-area, low-cost tandem modules.
- Increase in module size and improved efficiency: This trend involves the development of larger solar modules with higher efficiency. This can be achieved by using materials with higher conversion efficiencies, improving the manufacturing processes, and reducing the inactive area of the module. CdTe modules, for example, have achieved efficiencies of up to 19% in 2021, and researchers are continuing to work on improving the materials and processes used in these modules to achieve even higher efficiencies.
- Use of application-specific form factors: This trend involves the development of solar modules with specific form factors to optimize their efficiency for different applications. Inactive area can be reduced by using larger modules or adopting seamless or overlapping interconnection technology. Special interconnection and packaging materials can also be used to increase the efficiency of solar modules.
- Advancements in material combinations: This trend involves the development of new material combinations to improve the performance and reduce the cost of solar modules. For example, researchers are exploring the use of perovskite-Si tandems and other combinations to achieve high efficiency and low cost. Other research focuses on improving the durability and stability of solar cell materials to reduce degradation and improve the lifetime of solar modules.