Also, the wind speed affects the temperature of both the test and reference modules. Measurements were made at maximum wind speed (=5.4 m/s) in that day at 11:00 AM. The temperatures at the same time are the lowest (24◦C and 24◦C for front and rear faces of module with cooling and cleaning system against 35◦C and 49◦C for the reference module) as shown in Figs. 5 and 6.