Month

Jan

Feb

Mar

April

May

Jun

Jul

Aug

Sept

Oct

Nov

Dec

βopt (degree)

32

23

17

0

0

0

0

0

3

17

30

34

Optimum Irradiance (kWh/m2/day)

7.25

7.03

6.52

5.48

5.45

4.85

4.45

4.28

4.58

5.20

6.38

7.19

Irradiance for unique β (kWh/m2/day)

6.71

6.65

6.49

5.35

5.40

4.72

4.35

4.22

4.58

5.13

5.93

6.51