Any implementation of a sustainable photovoltaic solar energy system implies the optimization of the resources to be used. This is the basis of the design and assembly of solar installations to optimize the obtaining of renewable energy.
To achieve an optimal optimization of solar radiation, that is, the use of the Sun, knowledge of the solar path, the profile of the needs and the conditions of the location of the solar panels is essential. All this entails determining the orientation and inclination of the solar panels in fixed installations to achieve the minimum cost of the kilowatt hour of this type of renewable energy.
For reasons of architectural adaptation, solar modules are usually located on the roofs, even if it is not the area closest to the accumulation system or energy meters. For reasons of safety and architectural integration, the roof of the buildings is usually determined as the location zone of the photovoltaic solar panels.
The roof is a structural element of the building of which we must know basically four parameters: the available surface, the orientation, the structural load that it can support and the incidence of shadows that it can have. These elements will condition the arrangement of solar panels and anchoring systems.
One aspect to consider is the shadows that can affect the photovoltaic modules since during the day the leftovers vary in position, but also vary during the different seasons of the year. In winter, for example, solar radiation travels to the earth in a direction less perpendicular to the surface of the earth than in summer, so the shadows are much longer.
To achieve maximum use of a photovoltaic solar energy system, care must be taken of the incidence of possible shadows on the panels, both the nearby ones (objects that momentarily cover the direct radiation of the Sun) and the distant shadows (elements of the orography and / or landscape that hide the Sun from the area where the solar installation is located.
The effect of the shadows should be carefully evaluated when determining the location of the panels, since the shadows on the panels produce a significant reduction in production, especially if they occur in the central hours of the day (maximum insolation).
Location of solar panels
The available surface will be determined by the space of the roof in which the property determines to locate the photovoltaic panels. It will be necessary to ensure that this surface is an easily accessible space for maintenance operations, while this space must be protected from vandalism or falling objects.
Orientation and inclination of photovoltaic panels
The orientation and inclination of the photovoltaic panels depends on the latitude in which we are. The optimal orientation of the panels may be south or north and the optimum inclination will depend on the latitude of the place, the time of the year in which it is to be used and whether or not it has its own generator set.
Bearing in mind that on some occasions it is not possible to reach the appropriate inclination and orientation conditions, it will be necessary to evaluate, in any case, the losses of incident radiation due to location conditions.
However, there are conditions that can alter this premise. In mountain areas where snowfall is frequent it will be important to take advantage of the steep slopes of the roof that will benefit on the one hand, for its angle of inclination conducive to winter, and on the other side, because they will allow the snow to fall and not accumulate on top of the solar panels.
Separation between rows of solar panels
The separation between rows of photovoltaic panels must guarantee the non-overlap of shadows between the rows of panels during the winter / summer solstice.
This distance will be determined by the following expression, in the case of panels in horizontal arrangement (on a plane).
D = (h / tan (h)) · cos (a)
d, is the minimum distance between panel lines.
h, is the height of the panel line (vertically, from the top point on the floor).
tan (h) , is the tangent of the solar height (angle) in the most unfavorable month in our latitude.
cos (a), is the cosine of the solar azimuth in the most unfavorable month (December) at 10 solar hours.