Orientation of Solar Panels

A preliminary survey of the location and the proper arrangement of the PV array are important to maximize energy production of the Off-Grid PV system. The PV array needs to be installed with a proper tilt angle, azimuth angle and with the minimum of shading.


Tilt angle

PV arrays are most efficient, when they are perpendicular to the sun‘s rays. The default value is a tilt angle equal to the station‘s latitude. This normally maximizes annual energy production. The closer the system is installed to the equator the smaller should be the tilt angle. 

However, the farer the system is located from the equator the more the sun‘s path and the solar altitude vary throughout the year. In Europe for example the solar altitude during summer reaches 60 – 65° whereas in winter solar angles are as low as 13 – 18°. That means that the prefect tilt angle varies throughout the year. To optimize capture of solar panels a tilt angle of 28 – 30° in Europe is recommended, plus 15° in winter, or minus 15° in summer.


The following table shows the perfect tilt angle in different locations:

 Tilt Angle Locations

Tilt angle:

The closer the system is installed to the equator the smaller should be the tilt angle.

tilt angle


Geographical orientation – Azimuth angle

To maximize the collection of the daily and seasonal solar energy possible, PV modules should be oriented geographically. A solar panel facing the equator promises the highest energy yield. In the northern hemisphere the optimum orientation for a PV module is true south (Azimuth 180°), in the southern hemisphere it is true north. However, PV modules can face up to 45º east or west of true south (or north) without significantly decreasing their performance. 


Shading of photovoltaic cells

The electrical output of photovoltaic cells is very sensitive to shading. Even when a small portion of the panel is shaded and the rest remains in sunlight the electrical output decreases drastically. Shading from trees, poles, aerials, chimneys, existing or future buildings in the neighbourhood all have a major impact on photovoltaic energy production. The decreasing energy production due to shading has its electronic explanation in the series connection of solar panels. Due to a reduced flow of electrons or worst case electrons reversing course through the shaded portion of the p-n junction the power production of the whole  PV array suffers.