Comparative Study of Two Commercial Photovoltaic Panels under Natural Sunlight Conditions

Table 1

The month optimum angle for Brasov and the month average irradiance at optimum angles 35°, 44°, 55°, and 64°.

Month	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Opt. tilt (°)	63	55	44	29	16	9	13	25	40	55	64	65
(Wh/m^2/day)	1910	2550	4070	4570	4970	5100	5480	5260	4310	3830	2600	1640
(Wh/m^2/day)	2010	2630	4100	4470	4760	4830	5220	5110	4320	3960	2760	1730
(Wh/m^2/day)	2090	2660	4040	4250	4390	4390	4770	4800	4210	4020	2870	1800
(Wh/m^2/day)	2100	2640	3900	3980	4010	3950	4320	4450	4030	3970	2890	1820