Assuming a constant cell electrical conversion efficiency of 15%, a constant fraction of the incident solar radiation would be dissipated by the solar cell for each solar radiation intensity level. From Table 2, it can be seen that for the worst scenario when the ambient temperature was 50°C with natural convection only, the predicted cell electrical conversion efficiency would have reduced to approximately 8% rather than the 15% assumed. The energy dissipated as heat from the cell would thus be 7% higher. To correct for this effect the apparent insolation level should be modified using the following formula:(3)Iact=I×0.850.85+dηwhere Iact is the actual incident solar radiation intensity, dη is solar cell efficiency difference between the initially assumed 15% and final calculated cell efficiency based on measured cell temperature.
