Accelerated lifetime testing will not be done to confirm that it slows degradation (I don't have a 5000 W water-cooled xenon lamp anyway). Instead I will just check the temperature of the panel / cell with and without the TEG, exposed to the same conditions. If the temperature decreases significantly with the addition of the TEG, then assumptions about the potential increase in lifetime can probably be safely made. However, I have to take into account the differences in cooling afforded by different wind speeds/directions and ambient air temperatures. Active air cooling with a fan could be a slight improvement over passive air cooling, but I doubt it would have such a large effect on days with very high air temperatures. Perhaps it would be better to use water cooling; I could simply hook up a domestic cold water line from a sink or hose to some copper pipe on the back of the TEGs... that would generate much more power from the TEGs and would much more effectively cool the solar cell / panel. If I use active cooling, I should take into consideration the energy usage of cooling and moving the water or moving the air into any overall efficiency calculations.