Photovoltaic installation

Before installing solar panels on a home or building, it is important to consider several factors to ensure that the solar system is efficient and suits the homeowner's needs. Some of the most important aspects to consider are:

Evaluation of the roof or available space: it is necessary to evaluate the available surface area for the installation of solar panels, taking into account the size of the roof, orientation, inclination and shadows that may affect the performance of the system.

Energy consumption: it is important to know the current energy consumption of the house or building to determine the size of the solar system needed to cover the energy needs and reduce the energy consumption of the electrical grid.

Budget: the cost of the installation and solar panels should be carefully evaluated, as it may vary depending on the quality of the panels, the complexity of the installation and the geographical location.

Regulations and permits: it is necessary to know the regulations and permits required for the installation of solar panels in the region or municipality where the house or building is located.

Maintenance and warranty: Solar panels require periodic maintenance to ensure their correct operation and prolong their useful life.

El número de paneles solares necesarios para generar 5 kW depende de varios factores, como la eficiencia de los paneles, la ubicación geográfica, la inclinación y orientación de los paneles y las horas de luz solar en la zona.

En promedio, se necesitan alrededor de 10 paneles solares de alta eficiencia para generar 5 kW de energía. Pero esto puede variar dependiendo de las circunstancias específicas de cada caso.

Por lo tanto, es recomendable que se consulte con un instalador profesional de paneles solares para obtener una evaluación precisa y personalizada sobre las necesidades de energía de una vivienda o edificio en particular.

Características físicas del Panel Solar 450W 24V. Este panel tiene unas dimensiones de 2094x1038x35 mm y un peso de 24 kg. Tiene un coste actual de unos 175,00 € por unidad.

Generally speaking, it is recommended that a solar installation for a single-family home with four people provide between 5 and 10 kWp. This range of power will cover the energy needs of the home and, in the best of cases, it will generate a surplus of energy that can be injected into the electrical network or stored in an optional battery. It is important to note that the size of the installation required can vary depending on geographic location, the orientation and tilt of the solar panels, as well as the energy consumption of the home. Therefore, it is advisable to request a personalized study to determine the specific energy needs of your home.

The installation of solar panels without a solar energy accumulator can limit the use of the generated energy to a range of between 25 and 40%. However, if an accumulator is incorporated, the own energy consumption can increase up to 75%. Therefore, it is highly recommended to have a solar energy storage system in any photovoltaic installation to maximize its efficiency and profitability.

The estimated cost of a photovoltaic system without storage can range between 2,200 and 2,800 euros per kWp. It is important to keep in mind that these prices can vary according to different factors, so it is advisable to obtain a personalized quote. Likewise, it is possible to reduce these costs through subsidies and the fiscal optimization of the system, which can result in a more profitable and sustainable investment in the long term.

Discharging the electricity generated in the electrical network does not provide any or very few advantages to the operator of the photovoltaic installation. For this reason, it is more convenient to consume self-generated electricity. In addition, the acquisition cost of a kilowatt hour (kWh) of electricity purchased in the electricity market is currently around 28 cents, while the kWh of self-generated electricity costs 5 cents. In this sense, having a photovoltaic system will allow you to save significantly on your electricity bill and, in turn, contribute to the environment, since the energy generated comes from renewable sources.

In order to install a self-consumption system without surpluses, a building permit must be requested from the City Council and the current municipal regulations must be followed.

Depending on the power of the installation, the City Council will tell us if it is necessary to present a responsible declaration of work and/or a previous communication of work.

It is possible to start this installation without a response from the Administration, although it is preferable to wait. In some cases, it is possible that the municipal regulations require a building permit application, for which a technical project signed by a competent professional would be needed. Likewise, the City Council may request a study of loads and wind resistance for rooftop installations.

Installations of self-consumption solar panels without surpluses must comply with the corresponding electrical safety regulations and technical regulations for their connection to the public network. Therefore, it is necessary to respect the rules indicated in the REBT regulation according to ITC-BT-40, as well as the general and specific requirements for energy measurement and management included in the metering point regulation.

Self-consumption installations without surplus do not require a license from the City Council, although it is recommended to make the consultation.

In general, if the system has been installed according to the REBT and the power is less than 10 kW, it is sufficient to have an installation certificate. On the other hand, if the power is higher, the technical project must be approved and an operating authorization from the corresponding Autonomous Community would be required.

There are two types of photovoltaic self-consumption:

Installations connected to the electrical grid and those totally isolated from it.
The former can allow the use of the net balance in the electricity bill in the event that the surpluses produced are few, or the sale at market price of this energy if the surpluses are abundant.

On the other hand, off-grid installations usually have a series of batteries to store the energy generated by the photovoltaic modules and use it during the night.

It is common to install stand-alone electrical systems in homes or premises where there is no easy access to the electrical grid or where the costs of processing connections are excessive. In such installations, the total isolation of the electrical grid makes it essential to implement batteries that ensure the supply of electricity during the night or on days with low energy production due to adverse weather conditions.

It is important to note that, although the cost of construction and maintenance of these systems exceeds the cost of those connected to the electricity grid, the savings are significant, since it is not necessary to contract the energy supply from a commercial company. It is also crucial to carefully calculate consumption requirements in order to avoid possible power outages.

In general terms, the following steps are required for individual self-consumption installations connected to the low voltage power grid with a power equal to or less than 10 kW:

1. Previous studies: It is advisable to carry out a feasibility analysis that evaluates the possibilities of implementing a photovoltaic system in our home, as well as the budget required for the installation and the possible savings in the electricity bill, depending on our consumption profile.
In addition, it is important to verify possible limitations or restrictions that may affect the location.

2. Previous administrative procedures:
Including design documentation, Self-consumption Code (CAU), environmental and public utility authorizations, building permit and ICIO.

3. Execution of the installation: To ensure compliance with energy and industrial safety regulations, it is recommended to hire an installation company duly qualified in low voltage and in accordance with the Low Voltage Electrotechnical Regulation (REBT) and its complementary technical instruction ITC-BT-40. Once the installation has been completed, the installation company will issue the corresponding installation certificate to guarantee its correct start-up and safe operation.

4. Administrative records:

- Register of Low Voltage Installations.
- Administrative Register of Self-consumption.
- Administrative Registry of Electrical Energy Production Installations.
- Registry of Industrial Establishments.

5. Obtaining an activity license: Self-consumption facilities without surpluses and those with surpluses that are subject to compensation are not considered economic activities and, therefore, the corresponding procedure is not required.

However, in the case of self-consumption facilities with surpluses not subject to compensation, these could be considered as an economic activity, since they have the option of selling the surplus energy to the market.

In such a situation, it is recommended to consult with the town planning service of the town hall to determine if the procedure is necessary.