When making a photovoltaic installation in our house or company, it will be necessary to know exactly how to dimension said facility so that based on our real consumption it is as efficient as possible.
That\’s what it\’s for takes into account a number of factorssuch as, for example, how much space we have, what energy consumption we usually do, where geographically the property is located, what is the best orientation of the solar panels, etc.
Put yourself in the hands of a professional in the sector, to advise us on how to size a photovoltaic installation, therefore becomes essential. This will take a deep look at all our needs and the features of our property to recommend the best option before we do the installation. The number of solar panels we install will determine the amount of electricity we can self-consume. In this regard, we recommend that you use this solar self-consumption calculator to start evaluating your project.
Next we will look at the different factors to consider to dimension a photovoltaic installation in the most optimal way.
Previous aspects to consider before sizing a photovoltaic installation
Before sizing any PV installation, you will need to consider some essential factors up front:
- Energy consumption. A basic consideration before determining the size of any solar installation is to know what our energy consumption is. To calculate it, we have to look at how many kWh we consume during a year, discriminating the consumption during the hours of sunshine.
- available surface. We must have enough space to install the number of solar panels that are needed. It is necessary to take into account the shaded areas that limit the power to be installed.
- Orientation and pitch of the roof. In the case of the photovoltaic installation on the roof, we must take into account that the more available space we have facing South (South-East, South-West), the installation will be much more usable.
How to calculate the energy consumption of a property
Before sizing a photovoltaic installation, it is necessary to know as precisely as possible How much electricity will we need in our property?. For this, you need to know kWh that we consume and the hours of the day in which we make these consumptions. This data is essential to analyze how to size a photovoltaic installation and the number of solar panels that will be needed in it, as well as to know which type of installation is most suitable.
For example, it is not the same to consume the most energy during the day and to feed on the direct electricity generated by the photovoltaic panels, as it is to consume mainly when there is no sunlight, in which case we will have to have a storage of energy. system such as solar cells. In the electricity bill we can quickly and easily check the energy we consume (kWh).
Next, by means of an example, we see how to get the data on how much energy You will have to supply us with the PV installation based on our annual consumption.
Let\’s say, for example, that we have an annual consumption in sunshine hours of 20,000 kWh/year and that the geographical area in which we are located is the center of the peninsula, whose peak hours are 1,600 on average per year. . Solar peak hours are the result of the sum of the annual hours in which the solar panels receive 1000 W/m2, i.e. they work at maximum theoretical power.
The approximate calculation of the solar panels we need in our installation is as follows:
- Consumption of the house in hours of sunshine: 20,000 kWh/year.
- Peak sun hours in Madrid: 1,600 HSP.
- Total required power of solar panels: Home consumption / HSP = 20,000 / 1600 = 12.5 kWh = 12,500 Watt.
That is, a total power of 12,500 watts of solar panels will be needed. If the solar panels are, for example, 320 W each, the final calculation would be:
Total power of solar panels / Unit power of the panel = 39.06 solar panels -> 39 or 40 solar panels would be what we need in our installation for our annual energy consumption.
How to dimension the space required for the photovoltaic installation
Once we know the number of solar panels we will need, we need to check if we have the necessary space or surface area to install them. But to calculate the total space we will need for the solar panels we should ask ourselves the following questions: What type of solar panel will we install? because depending on the type, the sizes vary; Does the installation area have shadows? whereas, if applicable, those areas will not be able to be used; What is the orientation of our roof? because a roof that faces south has many more hours of light than one that faces north.
To calculate the area available for installation, it is also necessary to reduce obstacles we can find. These can be physical, such as a chimney, window, vent, etc., or in the form of shadows that limit the power of the solar panel. If there is not enough space available for the photovoltaic installation, we can always opt for more efficient solar panels, In this way, we will have to install less because it generates more energy per square meter.
