It is well known that thin film modules like CdTe have certain power meta instabilities depending on their short- and long-term history. For CdTe extensive dark storage (e.g. due to transportation or modules from warehouse) typically lead to a lower output power and requires extensive light stabilization prior indoor STC characterization. IEC 61215-1-2 states requirements for standard stabilization for new, out of the box CdTe modules. For single modules that might be feasible, but to verify larger batches extensive indoor light soaking is cost and time prohibitive and therefor alternative procedures to reliable determine the output power of CdTe modules is needed. However, current standards do not cover any particular stabilization for field aged modules. Pre-treatment and storage of the module play an important role in the quickly to determine output power. Short term illumination by flash-testing/measurement increases measured output power and basically compensate for short term meta stabilities. However, the final power depends on pre-history and on illumination duration and intermediate short-term dark storage. Different modes of operation (Voc, Isc and Pmpp) and different temperatures are investigated to accelerate stabilization utilizing artificial light. In general, higher temperature lead to an accelerated change of characteristic parameters of the PV module. The operation mode of the module during light soaking (Isc, Voc or Pmpp) does also influence the change behavior of the output power and to an immediate response of the module. In the last experiment “stability” was reached after approx. 30 hours of light soaking at 1.000 W/m². Therefor at least three different effects have to be considered, namely dark-storage, fast to compensate light effects (ms-range) and long-term saturation effects in the range of days.