The correct installation and location of solar systems has a very large impact on the efficiency of the installation and the resulting profitability of its use, so it is very important to pay enough attention to it. In order for the solar panels to achieve their maximum efficiency, it is necessary to find a shaded place for them and place them in a suitable position where they can absorb as much sunlight as possible. You have to install them in such a way that they will not be damaged by strong wind or snow, and of course by connecting electrical cables and installing the necessary equipment.
Solar Panel Installation – Which Side of the House?
The surface of the photovoltaic panels is quite large – in order to obtain 1 kW of peak power, cells with an area of almost 7 m2 are needed – therefore only a small number of people set them up on a plot that is close to the house, because in most cases it is a waste of space, and if you consider that you can’t shade them, it might just not be there at all. Panels are most often installed on the roof or facade.
Firstly, this is simply the most convenient option, and secondly, they are at such an altitude relative to other objects that there is a good chance that they will not be left in the shade. The greatest efficiency and power of solar modules can be obtained by arranging them with their active surface facing the sun. However, in the case of stationary panels, this can only be done for a moment, due to the fact that the Earth is constantly moving relative to the sun.
The best option would be to face the panels south and tilt them 30-40 ° horizontally, and the greater the deviation from this position, the less energy will be generated. However, even for panels that face South-East or South-West and tilt 25-55 °, the energy efficiency will still be satisfactory at around 90-95% of the maximum value.
Trackers – the way to control the panels
Mounting solar panels towards the sun, in such a way that the sun’s rays always reach the photovoltaic panels at right angles, requires constant rotation around their vertical and horizontal axes. For this purpose, trackers are used – brackets with automatically controlled mechanisms that move the panels so that they can keep up with the visible movement of the sun across the sky.
Despite the fact that such a solution seems to be perfect, it is rarely used. According to the research results, despite the fact that theoretically the amount of energy obtained from panels placed on the tracker may be 30% greater than from fixed panels, which are located in accordance with our latitude, in fact this profit is even half as much. This is related to, among other things, the need to protect against the wind – when it is gusty, the panels are automatically leveled. The markers increase the cost of a large installation (made of at least several dozen panels) by about 20%, and a small one is even greater value.
The panels become hot when exposed to the sun. This is also due to the current flowing through them, and an increase in the temperature of a polycrystalline cell by 1 degree Celsius will result in a decrease in its power by about 0.5%. The highest power of the panels was recorded at the temperature of 25 degrees Celsius, when in summer it happens to be higher than 50 degrees. In turn, a panel with a nominal power of 250 W provides less than 220 W with a radiation intensity of 1000 W / m2. This has to be taken into account during installation and ventilation. It is important to ensure free air circulation around the panels. As a result, it is best to place them in an open space – near the house or on a flat roof.
They are often mounted a few centimeters above the roof slope, parallel to it, so that no significant drop in performance (less than 5%) is observed. When the panels are placed directly on the roof without providing airflow, you can expect 10% less energy gain.
Shading of panels
A shade on a solar panel equates to less energy being transferred to the solar cells. The big problem is that even when only a small part of one cell is obscured by, for example, a sticky leaf, all the cells that are connected to it will supply less energy. This can make the operation of the panels invisible despite the sunny weather due to relatively little contamination or shading of the panel parts.
Even seemingly innocuous poles, masts or electrical cables that cast a small shadow can be a problem. Try to keep as much distance as possible from them when installing panels, and all moving parts such as antennas are best placed on the other side of the roof.
The energy from the shaded cells is lost by the reverse current flowing through the shaded cells, which then takes on the role of resistors. The effect is an increase in temperature.