Understanding albedo can improve the efficiency and performance of solar PV power
systems. Let’s unpack this and learn how to optimise albedo.
Albedo, in the context of solar power, refers to the measure of a surface’s reflectivity.
It is expressed as the ratio of the reflected solar radiation to the incoming solar radiation. In basic terms, a surface with high albedo reflects a large portion of the solar energy that strikes it, while a surface with low albedo absorbs more solar energy.
A perfectly reflective body would have an albedo equal to 1 (100% reflection), while a perfectly absorbent one, which doesn’t reflect any light, has zero albedo. A ground albedo of 10% means that if the direct solar radiation received by the ground is 1 kilowatt, the amount reflected is 100 watts.
The magnitude of albedo is determined by several factors characteristic of the surface to which it relates. These include colour, texture, irregularities, and the presence of dust or water.
The natural albedo of soil at solar installation sites is between10% and 30%, depending on the vegetation cover.
Under certain conditions, this value can vary. For example, snow cover can be as high as 50%,while variability also results between ploughed or rainfall-compacted soil. Other conditions are the inclination of the sun’s rays (determined by the latitude) and weather conditions.