The reaction system is also seamlessly scalable and delivers quasi-identical irradiation conditions (photon flux density and distribution) over different reactor scales as long as the fill factor as dimensionless parameter is kept constant. The resulting reaction profiles are also the same regardless of scale, which vastly simplifies scaling up reactions in this system. This was demonstrated here for scales of 25 to 75 mL but an earlier study also showed this for 1 to 360 mL scales. Overall, this now optimized reaction system using wireless light emitters present very a promising technology for photochemical reactions which provides unprecedented photon flux density and efficiency in a fully scalable system.