Longi worked with DNV in Texas to analyze the impact of large format modules on the balance of system (BOS) cost of a photovoltaic power plant. The firms compared 182-72c, 210-55c and 210-60c modules of 500W+ front power arranged in three different racking structures—1P tracker and 2P and 4L fixed rack. The firms found only a slight difference in the three modules and concluded that the 182-72c module had higher efficiency.
The firms applied half-cut and multi busbar interconnection technologies to all three modules and assumed a large-scale power station on flat land for the calculation. They also assumed the same length for fixed racking, same cable power loss and same cost of installation per watt.
Below is a table listing the BOS cost of the modules:
The table shows that the BOS cost of a 182-72c module is less than that of a 210-55c module and a 210-60c module by 78₵/W and $1.19/W, respectively, when the 1P tracker is used. This lower cost can be attributed to the lower cost of tracker support and land. When a 2P fixed racking configuration is used, the BOS cost of the 182-72c module is still lower than that of a 210-60c module by16₵/W. This difference is also attributed to reduced land and racking costs owing to a difference in efficiency. Although the boundary conditions remain similar with a 4L fixed rack and a 2P fixed rack, there is a great difference in the land-related costs as the 182-72c module’s efficiency is 0.27% higher than that of the 210-55c module. Thus, the superiority in BOS costs of up to 34₵/W.
The study reveals that using over-sized modules with a higher current will not lead to BOS cost savings because module efficiency remains the most critical factor in BOS costs.
Please find more detailed comparisons of the BOS costs in the tables below:
