How to Measure?

1.

Facing south, a 360° panorama picture will be taken from the measuring premises. The sun path will then be overlaid on the picture.

2.

According to the sun blockage on different time of the day and different season of the year, the solar index can be calculated.

The sample below show the 360° panorama skyline pictures as viewed from three different locations of high, medium and low solar energy potential. The sun paths on 21 Dec (Winter), 21 Mar (Spring, also stands for the autumn sun path), 21 Jun (Summer) and 24 Nov 2013 (measurement date) are overlaid on the pictures to facilitate the estimation of the sun blockage. The center line of the photo is facing south.



360 ° panorama skyline pictures:

  • Sun path in June
  • Sun path in March
  • Sun path in December
Month Daily MJ/m2 Solar shading pattern for hourly period ended at
6am 7am 8am 9am 10am 11am 12pm 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm
Jun 14.5
Solar energy distribution (%) 0.1 1.4 3.8 6.6 8.6 11.0 13.2 13.9 11.5 10.0 9.1 6.7 3.4 0.9 0
7.7% of solar energy would be shaded in a typical day in Jun
Mar 9.9
Solar energy distribution (%) 0 0.2 1.8 4.7 7.8 10.9 13.8 15.0 15.0 13.6 9.6 5.6 2.0 0.1 0
2.3% of solar energy would be shaded in a typical day in Mar
Dec 11.0
Solar energy distribution (%) 0 0 1.2 5.0 9.5 13.7 15.8 16.5 14.7 12.4 7.9 3.1 0.2 0 0
3.3% of solar energy would be shaded in a typical day in Dec
Remark:

darker box assumes shading throughout the hour

grey box assumes 50% shading in the hour

Upon calculation, the solar performance on this location is 95.73% (which corresponds to 4.27% of the solar energy will be shaded). Therefore, this location is considered to have high solar energy potential for solar panel and solar water heater installation.

  • Sun path in June
  • Sun path in March
  • Sun path in December
Month Daily MJ/m2 Solar shading pattern for hourly period ended at
6am 7am 8am 9am 10am 11am 12pm 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm
Jun 14.5
Solar energy distribution (%) 0.1 1.4 3.8 6.6 8.6 11.0 13.2 13.9 11.5 10.0 9.1 6.7 3.4 0.9 0
4.4% of solar energy would be shaded in a typical day in Jun
Mar 9.9
Solar energy distribution (%) 0 0.2 1.8 4.7 7.8 10.9 13.8 15.0 15.0 13.6 9.6 5.6 2.0 0.1 0
17.5% of solar energy would be shaded in a typical day in Mar
Dec 11.0
Solar energy distribution (%) 0 0 1.2 5.0 9.5 13.7 15.8 16.5 14.7 12.4 7.9 3.1 0.2 0 0
40.6 % of solar energy would be shaded in a typical day in Dec
Remark:

darker box assumes shading throughout the hour

grey box assumes 50% shading in the hour

Upon calculation, the solar performance on this location is 81.08% (which corresponds to 18.92% of the solar energy will be shaded). Therefore, this location is considered to have medium solar energy potential for solar panel and solar water heater installation.

  • Sun path in June
  • Sun path in March
  • Sun path in December
Month Daily MJ/m2 Solar shading pattern for hourly period ended at
6am 7am 8am 9am 10am 11am 12pm 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm
Jun 14.5
Solar energy distribution (%) 0.1 1.4 3.8 6.6 8.6 11.0 13.2 13.9 11.5 10.0 9.1 6.7 3.4 0.9 0
38.7% of solar energy would be shaded in a typical day in Jun
Mar 9.9
Solar energy distribution (%) 0 0.2 1.8 4.7 7.8 10.9 13.8 15.0 15.0 13.6 9.6 5.6 2.0 0.1 0
45.4% of solar energy would be shaded in a typical day in Mar
Dec 11.0
Solar energy distribution (%) 0 0 1.2 5.0 9.5 13.7 15.8 16.5 14.7 12.4 7.9 3.1 0.2 0 0
44.5 % of solar energy would be shaded in a typical day in Dec
Remark:

darker box assumes shading throughout the hour

grey box assumes 50% shading in the hour

Upon calculation, the solar performance on this location is 56.6% (which corresponds to 43.4% of the solar energy will be shaded). Therefore, this location is considered to have low solar energy potential for solar panel and solar water heater installation.