What is Magnetic Declination?
Magnetic declination, the angle difference between magnetic south and true solar south, must also be taken into account when determining proper solar array or solar panel orientation. If a magnetic compass alone is used to determine where to point the array, you may not capture the maximum amount of solar radiation. For a general view of the magnetic declination field lines in North America, see the map below.
If you wish to gain in-depth information about magnetic declination, visit the following website: http://www.ngdc.noaa.gov/seg/geomag/declination.shtml .