We present data at both the single cell coupon level and at the module level that demonstrate that the shunting from cracks reduces performance at low irradiances significantly more than at 1-Sun conditions, and that the effect scales with the total length of the cracks. We show through simulations that energy delivery may degrade significantly more than Pmax with damage from cracked cells. We conclude that the degradation from accelerated testing and field exposure should be assessed not just at an irradiance of 1-Sun but also at lower values as well.