Enhancement of Power Output From a Large-Area Luminescent Solar Concentrator With 4.8× Concentration via Solar Cell Current Matching

The irradiance concentrated along the edges of a planar luminescent solar concentrator (LSC) is not uniform across their length. This geometrical effect results in a deviation of up to 40% between the extreme ends and the middle of an edge for a large-area LSC. Consequently, the typically in-series interconnected solar cells attached to the edges of the LSC are not illuminated equally resulting to current mismatch. It is shown that by reducing the lengths of the more central solar cells so that current matching is achieved, more cells can be attached to each edge. This way, the voltage and power output of the string can be increased. In this work, a 60 cm × 60 cm × 0.3 cm LSC with 26 solar cells mounted to its edges was constructed and characterized. These dimensions result in geometrical concentration of 50×, while the LSC exhibited average irradiance concentration of 4.8×. An increase of 15% in power output and efficiency is demonstrated via the reduction of the length of central cells, current matching, and the consequent connection of one more cell to the string of an edge. A solar-to-electric power conversion efficiency of 1.55% is reported for the large-area LSC module.