INTRODUCTION
Rows should have sufficient spacing to prevent shading and maximize solar yield. The required row spacing depends on the following (for north facing rows):
- Geographic location (in particular, the latitude)
- Vertical distance between the top of one row and the base of the next
- How many hours of the day the rows must remain unshaded
DETERMINING THE CORRECT SPACING
Measure vertical difference
Measure the vertical difference in height between the lowest part of one row and the highest part of the next row. This takes into account the slope of the roof or ground.
Multiply this height by a factor
To determine the gap between the panels, multiply the height by a factor. This factor accounts for the location of the sun (altitude and azimuth) on the winter solstice. At minimum (and in accordance with CEC guidelines) the panels should not be shaded between the hours of 10 am to 2 pm.
To further minimize shading and maximize yield, it is recommended to avoid shading from 9 am to 3pm. If a lot of space is available then an even better solution is to avoid shading from sunrise (+ one hour) to sunset (- one hour), as shown in the following table:
Add this to the row width
To get the row spacing add the row width (width of the panels) to the row gap (just calculated).
WORK EXAMPLE
Measure height
Solar modules are installed on 15° commercial roof brackets on a north facing roof with a pitch of 3°. The difference in vertical height is ~ 260mm. For 10° commercial roof brackets, use vertical height of ~ 160mm.
Multiply this height by a factor
The solar modules are installed in Perth and should be unshaded from 9 am to 3 pm on the winter solstice. Use the SunLock factor of 2.3. Therefore, the row gap is 260 mm x 2.3 = 598 mm.
Add this to the row width
The solar module has a width of ~ 956 mm. Therefore, the total row spacing is 956 mm + 598 mm = 1554 mm.
LOOK UP TABLES
Commercial roof brackets on a north facing roof with a 3° pitch:
Note: minimum row spacing is 1200 mm.
Commercial roof brackets on a south facing roof with a 3° pitch:
Note: minimum row spacing is 1200 mm.
For Further information
For further information contact SunLock on 1300 655 554 or order@sunlock.com.au.