Independently of the light intensity, a part of the higher efficiency in the WLE system may also be attributable to increased reflection losses in external irradiation due to the highly opaque reaction medium, as observed previously for similar cases. This highlights a tremendous advantage of the WLE system versus external irradiation. The fact that the light intensity can be increased without actually increasing the maximum irradiance anywhere in the reactor can prevent efficiency losses at high light intensity and thereby lead to significantly increased photon efficiency. Table summarizes the obtained results from the different setups analyzed herein. Overall, the third iteration of our WLE system presented herein exhibits exceptionally high light intensity and energy efficiency, full seamless scalability and advantages pertaining to the better light distribution. This is also illustrated in Figure which shows the performance of the system described herein in comparison to other photochemical reaction systems. The improved WLE system shows amongst the highest efficiency (PSTY) of all published systems and at the same time, achieves productivity values (STY) comparable to microcapillary systems, while being readily scalable into the liter dimension. It therefore presents a very promising reaction system for photochemical processes, particularly for industrial implementation. References to the values are given in Table .