How Electricity Is Distributed

Electricity distribution is the process that ensures electricity generated at power plants reaches homes, businesses, and industries safely and efficiently.

This process involves transporting electricity from transmission networks or from generation plants connected directly to the distribution grid, to consumption points, ensuring proper quality and continuity of supply.

What Are the Phases of Electricity Distribution?

This process consists of several interconnected phases. These intermediate and final stages within the electrical system allow electricity to travel from electrical substations to consumption points.

Primary Distribution Network – Subtransmission

In this stage, electricity is transported at medium voltage from substations to transformer stations.

The primary distribution network handles voltages typically ranging from 13.2 kV to 44 kV and consists of distribution lines that connect substations to transformer centers.
 

Secondary Distribution Network

The secondary distribution network is responsible for transporting electricity. In this phase, voltage is reduced to levels suitable for use in homes and small businesses, generally to 400/230 V.
 

Final Transformation

Final transformation takes place at transformer stations, where the voltage is adjusted to the levels required for domestic or commercial use.
These stations contain transformers that step down the voltage from medium to low.

Distribution to the End User

Once electricity is transformed to low voltage, it is distributed to end users through distribution networks that reach consumption points.

This process ensures that electricity arrives with the quality and continuity needed for everyday use.
 

Electricity Distribution Components

Electricity distribution relies on various grid components that ensure its operation. 

Some of the most important elements in this process include:
 

• Transformer stations: Facilities that house transformers and other equipment needed to reduce voltage and enable distribution.
• Transformers: Devices that modify electricity voltage, allowing it to be adapted for transport and use.
• Primary and secondary distribution switchgear: Equipment that enables connection, protection, and operation of medium and low voltage distribution lines.
• Protection and automation units: Systems that monitor and control the distribution grid, ensuring its safety and efficiency.
• Low-voltage panels: Components that distribute electricity to various consumption circuits in residential or commercial installations.  

What Role Does the Electricity Distributor Play?

The electricity distributor is responsible for operating, maintaining, and developing the distribution grid. 

At i-DE, part of the Iberdrola Group, we manage one of the largest infrastructures in Spain, with over 265,000 km of power lines.

We are committed to digitalization and the development of smart grids to provide an increasingly efficient, sustainable, and adaptable energy supply. 

La actividad de distribución de energía eléctrica tiene por objeto la transmisión de energía eléctrica desde las redes de transporte o desde las centrales generadoras conectadas a la propia red de distribución, hasta los puntos de consumo en las adecuadas condiciones de calidad con el fin último de suministrarla a los clientes.

En términos generales, tienen la consideración de instalaciones de distribución todas las líneas, parques y elementos de transformación y otros elementos eléctricos de tensión inferior a 220 kV, salvo algunas excepciones contempladas en la Ley del Sector Eléctrico.

You might also be interested in