We present a low-temperature time-resolved cathodoluminescence study on (In,Ga)N/GaN quantum wells grown on the (11-22) facets of non-coalesced ELO-GaN. Taking advantage of the quantum confined Stark effect, such structures have been proposed as promising monolithic white light emitters. Here, we show that in order to achieve solar-like white light emission from this kind of structure, one has to pay attention on the respective evolutions of radiative and non-radiative QW exciton decay times along the (11-22) facets.