Many times when we think of putting solar panels In any building, we consider the total number that we should place in that place. For this reason, through this article, we are going to explain to you in a simple way. clear and simple way how to calculate this number so that it is much easier for you when installing them. This method, for its part, can be used both for a house and for another type of property in which a certain amount of energy is needed that will reach us through these solar panels.
First of all, you should know that solar panels can be placed both in series or in parallel. This must be taken into account, but we must also analyse the energy produced by a solar panel and based on this, we can calculate the total number of solar or photovoltaic panels needed. In addition, the performance of the system and the geographical location play a key role in optimising its usefulness.
It is also essential to take into account the different types of solar panels available on the market, since the type of panel will determine the efficiency of capturing and converting solar energy. The ideal is to opt for high-quality panels, regardless of the fact that the initial cost is somewhat higher.
Solar panels: an installation increasingly used in any type of home
To calculate the energy generated by a solar panel during a single day, we must apply the following formula. In this case, the total panel energy is the result of the maximum panel current times the maximum panel voltage per hours of the peak sun and by 0,9 which is the coefficient of panel performance. The formula is: Epanel = Ipanel Vpanel · HSP · 0,9 [Whd].
On the other hand, we must also know the energy generated by a single solar panel. In this case, it is also calculated in a very simple way. The formula is as follows:
Ephotovoltaic-generator = Iphotovoltaic-generator Vphotovoltaic-generator · HSP · 0,9
It should be noted that this is the energy generated by a single solar module, but if what you really need to know is how much energy the entire solar installation (which has several solar panels) will be able to generate, the formula is different.
In this case, the current is the result of the association of the photovoltaic modules connected in parallel while the voltage It is obtained from the sum of all the voltages of each of the branches connected in series.
By following these formulas, you can easily find out the number of solar panels you need, both in your home and in any other premises or building.
Key factors to determine the number of solar panels needed
While the formulas mentioned above are useful for understanding the electricity generation by a panel, calculating the exact number of modules will also depend on several additional factors. Below we detail the most relevant aspects that directly influence the sizing of the photovoltaic installation:
- Annual energy consumption: The most important factor is the amount of energy your home or building consumes. For residential homes, this can vary significantly depending on the use of appliances, electric heating, etc.
- Power of solar panels: Solar panels range in output capacity from 250W to 450W or more. The more power, the fewer solar panels will be needed.
- Geographic location and peak hours of sunshine: The amount of sunlight available is crucial, as it influences how much energy each panel can produce. In regions with more peak sunshine hours, you may need fewer panels to cover your daily consumption.
- Shadows and roof orientation: Location and possible obstacles such as trees, antennas or chimneys affect the efficiency of the panels. Orienting the panels towards the south is the most recommended in Spain.
Taking these factors into account, we can make a rough estimate of the number of solar panels needed. If, for example, you consume approximately 6.000 kWh per year and your panels produce 400W, you will need around 15 panels in a location with a good amount of sunlight hours.
How to calculate the number of solar panels needed based on the available space?
The space available on your roof or land is another key factor in determining the exact number of panels you can install. Depending on the size and shape of the surface, you may need to opt for higher efficiency solar panels if space is limited.
In the following examples you can see how many panels can be installed depending on energy consumption and available space:
| Available surface area dimension | Annual energy consumption | Number of recommended panels |
|---|---|---|
| 30 m2 | 3.000 kWh | 8 to 10 panels |
| 50 m2 | 6.000 kWh | 12 to 15 panels |
| 70 m2 | 9.000 kWh | 18 to 20 panels |
Typically, a standard solar panel takes up approximately 1,6 m², so carefully measure the available surface area on your roof before beginning installation.
Solar panels: contribution to the environment and biodiversity
In addition to reducing energy bills, solar panels play a key role in protecting the environment and biodiversity. By using solar energy, we are reducing our dependence on non-renewable energy sources that emit polluting gases, such as coal or natural gas.
A recent report on the global photovoltaic industry highlights that, in 2023, 75 GW of new solar capacity was installed, with an increasing trend for the coming years, where it is expected to reach 85 GW in 2024. Much of this capacity is led by the Asian continent, especially China, however, Europe, and in particular Spain, is beginning to catch up in this regard thanks to specific incentive policies and an increase in environmental awareness.
Solar panels also make it possible to improve the impact on biodiversity, especially in regions where hydroelectric stations and fossil fuel plants are implemented in fragile natural areas. By placing solar modules on already urbanized areas, such as the roofs of homes and factories, we reduce the need to intervene in natural habitats.
Thanks to its ease of installation and rapid amortization of the initial cost, solar energy is positioning itself as one of the best sustainable solutions to reduce the carbon footprint in homes.
With proper planning, the use of solar panels can help cover the energy needs of a home and also significantly reduce the monthly electricity bill. Taking advantage of the hours of sunlight based on a good orientation, avoiding shadows and ensuring the correct installation of the modules are critical aspects that should not be overlooked.
IT IS OF GREAT IMPORTANCE TO APPLY THIS TECHNOLOGY IN EXISTING HOUSES AND TO PROJECT NEW HOUSES WITH SOLAR TECHNOLOGY AS THE FIRST BASIC NEED