# Example of Calculation of the Shading Correction Factor kB

Using Figure 2.34, the calculation procedure for shading correction factor kB for a solar generator at 47°N with b = 45° and g = 15° will now be described. After the solar generator azimuth g = 15° and the horizon have been entered in the shading diagram for 47°N, it emerges that shading occurs only from October to February. Hence kB needs to be determined for this period.

The following is obtained for October’.

SGPS = 21 ■ 3% + 15 ■ 2% + 5 ■ 1% = 98%

SGPB = 1 ■ 2% + 1 ■ 1% = 3% ) kB = 1 – SGPB/SGPS = 0.97 The following is obtained for November.

SGPS = 23 ■ 3% + 12 ■ 2% + 2 ■ 1% = 95%

SGPB = 2 ■ 2% + 2 ■ 1% = 6% ) кв = 1 – SGPB/SGPS = 0.94

Figure 2.34 Complete shading for kB calculation, with the solar generator azimuth and the horizon entered

The following is obtained for December:

SGPS = 25 ■ 3% + 12 ■ 2% = 99%

SGPB = 2 ■ 3% + 5 ■ 2% = 16% ) kB = 1 – SGPB/SGPS = 0.84 The following is obtained for January:

SGPS = 24 ■ 3% + 12 ■ 2% + 1 ■ 1% = 97%

SGPB = 1 ■ 3% + 4 ■ 2% + 1 ■ 1% = 12%

) kB = 1 – SGPB/SGPS = 0.88

The following is obtained for February:

SGPS = 21 ■ 3% + 14 ■ 2% + 4 ■ 1% = 95%

SGPB = 1 ■ 2% + 2 ■ 1% = 4% ) kB = 1 – SGPB/SGPS = 0.96

With kB = 1 for the remaining months.

Section A5 contains shading diagrams for 41, 44, 47, 50 and 53°N that were realized using the same method, as well as an assessment diagram with the same scale, which can be used as a master copy. These documents allow for sufficiently accurate calculation of the shading correction factor kB for Central Europe and much of Southern Europe.

The shading correction factor kB can in turn be used to calculate irradiated direct beam energy in a manner that takes account of shading. This calculation is performed in the guise of a correction of Equation 2.15 by multiplying by kB:

Updated: August 2, 2015 — 7:55 pm