Another important aspect of the set of materials necessary for the realization of a solar photovoltaic system is the choice of the PV solar bracket. This structure ensures a good anchoring of the solar panels, while providing the necessary inclination and orientation for the best use of solar radiation.
The PV solar bracket performs a double mission. On one hand, mechanical, with an adequate anchoring and support, and on the other, it provides the ideal inclination to get the most out of solar radiation.
The climatic conditions of the installation site of the solar panels will also influence the support structure. For example:
In places of strong winds, the number of fixings will have to be reinforced and the structure reinforced. The support structure will have to resist this overload.
The same as in the case of the wind, it occurs with the effect produced with the snow, which increases the overload of the structure, the weight to be supported by the structure is greater. In this case, a greater inclination is usually given to avoid their accumulation.
Saline environments (for example near the coasts) will influence the type of material used for its construction.
1. Aluminum. It is of easy mechanization, great resistance and low weight. It is very convenient that it is anodized aluminum, because it presents better resistance to corrosion and is more aesthetic, than the standard crude finish.
2. Iron. It is found in a wide range of dimensions, shapes and thicknesses. They must be subjected to a galvanizing process to confer anti-corrosion properties. This galvanic bath should incorporate a thickness of not less than 100 microns to the surface, for perfect protection.
3. Stainless steel. It is widely used in saline environments. If a structure of this material is used, it must be taken into account that if the frame of the solar modules is made of aluminum, it should avoid direct contact of both materials, by means of an insulator, since these two materials produce a high galvanic corrosion, especially in saline environments.
The optimal orientation is always SUR (if we are in the north hemisphere), since it is the position from which the sun's radiation is used throughout the day.
Because the trajectory of the sun's radiation has a short winter travel and more horizontal than in summer. This is the reason why, in order to take advantage of the winter radiation, a greater inclination of the support is needed. To influence the solar rays on the surface of the panel at an angle as close as 90º.
Therefore, the optimum inclination of the PV solar bracket will depend on the latitude of the installation site and the design period of the solar installation. Thus, it is recommended to use one of the following inclination values depending on the period of predominant use of the installation:
a) Constant annual demand: the optimum inclination in degrees is equal to the geographical latitude in degrees minus 10. (Optimum inclination = f-10).
b) Preferential demand in winter: the optimum inclination in degrees is equal to the geographical latitude in degrees plus 10. (Optimal slope = f + 10).
c) Preferential demand in summer: the optimum inclination in degrees is equal to the geographical latitude in degrees minus 20. (Optimal slope = f-20).