From cell to photovoltaic generator: modularity
Photovoltaic electricity and energy transition: From sunlight to PV generator

Thanks to advances in the semiconductor industry, the unit size of PV cells has increased significantly since their inception. Initially round in the 1970s (diameter 57 mm in RTC-BPX 47 A modules), as shown in Figure 37a, they became square for better tiling of the occupied surface, dominated by typical sizes of 125 mm on a side until 2010. They have now evolved to standards around 157 mm square. With typical energy efficiencies of between 15 and 22%, the maximum unit power of a large crystalline silicon cell is therefore of the order of 5 W. What's more, the voltage V _p delivered by a cell is constrained by the gap energy E _g of the materials; silicon cells typically deliver 0.5 V at the point of maximum power. The result is a very low-voltage, low-power DC generator for most domestic and industrial...