Experimentally analyzing the photovoltaic (PV) performance and the photon transport mechanism of large-area luminescent solar concentrators (LSCs) (>200 cm(2)) has proven difficult because common solar simulators and integrating spheres have limited measuring capacity. This report introduces an approach of regional measurements to address these issues using common laboratory instruments. In this approach, the LSC is configured to have different surface and edge regions. The surface regions are sequentially illuminated by a low-cost solar simulator, and the edge regions sequentially measured by a small-area solar cell or a general photoluminescence (PL) spectrometer. The methodology is validated through the comparison with the conventional method and Monte Carlo ray-tracing simulation in the study of the PV performance of a series of R305-based LSCs. Experimental results from the regional measurements reveal important the photon transport mechanism of the LSCs. The results show that severe photon transport loss exists within a surface distance (d(surf)) of 5 inches (12.7 cm), and photons with the longest average transport distance ((max)) experience number of absorption events (N-abs) for an average of 11.3 times. The approach of regional measurements can effectively measure the PV performance and investigate the photon transport mechanism of large-area LSCs. (C) 2020 Elsevier Ltd. All rights reserved.