More and more people are considering installing a photovoltaic solar system in their home. Saving energy efficiency and environmental awareness, as well as increasingly competitive prices, make this an option that is gaining ground. As we always insist, it is essential to go hand in hand with a professional who will tell us how the installation should be structured and the number of modules or solar panels that we need.
The best area to place the solar panels is the one with the greatest exposure to sunlight. Therefore, roofs, whether flat or sloping, are a good solution, as long as they are not oriented to the north. If the roof for different reasons is not suitable, another option is to carry out the installation on the spot. In any case, we will focus on rooftop installations, which is always the simplest and cheapest option to carry out the installation.
The optimal conditions for solar capture occur when the solar modules are oriented to the South and with an inclination that is around 30º, although roofs with lower inclinations are also capable of installing solar modules with very high performances.
The energy required, energy consumed of solar panels and place of the house
Depending on the type and size of the roof, our photovoltaic system will have one or other characteristics. We can investigate, study, or calculate how it will be but it is essential that we contact a specialized company that will carry out a complete study. Both the study and the design and assembly must be carried out by accredited professionals who guarantee the perfect use of the entire photovoltaic installation.
In any case, we indicate three aspects that you need to know to calculate the amount of photovoltaic panels to install.
- Hired potency. If we want the system to cover a large part of the housing needs, we will have to know what contracted power we have with the electricity company. This contracted power refers to the number of kilowatts (kW) that we can connect simultaneously in our home.
- Amount of energy consumed. Contracted power is not the same as consumed energy. It is essential to know the average consumption by months throughout a year and to know the average daily consumption to design a photovoltaic installation that responds to the different energy demands throughout the year. Consumption not only has to do with the type of housing and number of users or habits, but it also influences the climate where it is located.
- Location of the home and hours of solar radiation. Depending on where the house is located, the solar panels will receive more or less solar radiation. Spain has one of the highest solar radiation in Europe and even in the north, the installation of solar panels is a recommended option. There are tables that calculate the Peak Solar Hour (HSP) for each location. The Peak Solar Hour is used to perform photovoltaic calculations and is a unit that measures solar irradiation and is defined as the time in hours of a hypothetical constant solar irradiation of 1000 W that a square meter of surface receives. In summary, if there are 5 HSPs in this place, we have 5 hours of sun that is transmitting 1000W / m2. But this energy is not the same according to location and also varies according to the time of year and atmospheric conditions.
It is important to note that there are different types of photovoltaic solar panels module with greater or lesser power . The higher the power of the panel, the less number of panels required logically.
With all these data we can calculate the number of solar panels needed. Although it is much more complex and that is why it requires professionals capable of using computer programs that take into account the different variables: location of the roof, orientation, and inclination of the modules, type of inverter, need for batteries, consumption in the different times of the year, etc … and in this way ensure that the design of the photovoltaic installation is adjusted to the real needs of the home, business or industry.
Before choosing a photovoltaic solar panels installation, we must know the characteristics of our home, our needs and what we want the system to offer us.
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