In recent years, photocatalysis has seen a renaissance in synthetic chemistry, sparked by the emergence of the so-called photoredox chemistry. Due to their unique reactivity, often featuring high-energy or radical intermediates, photocatalytic reactions often unlock new reaction pathways with potential shortcuts in many syntheses processes. Consequently, they promise reductions in process steps and thus in reagents and waste production, leading to more sustainable processes. Moreover, hazardous and toxic high-energy reagents can often by replaced by light energy, offering additional benefits. Due to these advantageous properties, photocatalytic reactions are also employed more frequently in the chemical industry, particularly in the synthesis of fine chemicals and pharmaceutical compounds. However, the technical implementation of these reactions is faced with several challenges, mostly related to the difficulty of supplying and distributing sufficient numbers of photons into larger dimensioned reactors due to the exponential decrease in light intensity in the typically strongly absorbing media. For these reasons, industrial implementation is still limited to a few cases and only on a small scale. The issue of low penetration depth is typically addressed by either by using smaller dimensioned reactors such as microreactors, or by internal illumination. The former has the disadvantage of being limited to cost-intensive numbering-up for larger volumes and potential challenges when using heterogeneous catalysts, bases or potential precipitates. The small dimensions also typically lead to energetically inefficient irradiation as many photons are transmitted, scattered or just off target. Internal illumination can be realized with immersion lamps, although that typically still leads to rather high average optimal path lengths. Another option is using delocalized internal illumination with many small light emitters. Such Wireless Light Emitters (WLE) can free move inside the reaction medium and distribute the light evenly. They may also be powered wirelessly from outside the reaction medium, avoiding high voltage connections which may present explosion hazards.