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Substations at a glance – your knowledge hub for everything to do with substations

A substation is a key electrical facility within the electricity grid and connects different voltage levels. Without this technical infrastructure, it would not be possible to transmit electrical energy safely, efficiently and with minimal losses over long distances. In this knowledge hub, we explain in clear and technical terms how a substation works, what components it consists of and what role it plays in ensuring a stable energy supply.

Aerial view of an electrical substation with power transformer, high-voltage switchgear and grid connection point for feeding electricity from a large solar farm into the power grid.

The basics explained

What is a substation?

A substation is an electrical facility in which electrical energy is transformed from one voltage level to another. At its heart is the transformer, which either steps up the voltage or steps it down to a lower level. For example, the electricity generated in a power station or in renewable wind and solar power plants is first stepped up to a high voltage so that it can be transmitted over long distances with minimal losses. At its destination, the voltage is stepped down again before being supplied to consumers.

Voltage conversion is necessary because different parts of the electricity grid operate at different voltage levels – from the high-voltage level in the transmission grid, through medium voltage, to low voltage at the end user’s premises.

Technology made easy

How does a transformer work?

The transformer utilises the magnetic coupling between two coils to transfer electrical energy from one circuit to another, thereby changing the voltage. Energy is transferred between the windings via a changing magnetic field, without there being a direct electrical connection. In this way, electrical energy can be transformed precisely and efficiently from one voltage level to another – the basis of every substation.

Components in detail

Structure and components of a substation

A substation consists of several interlinked components. The busbar bundles the incoming and outgoing power lines, whilst the circuit-breakers reliably cut off the supply in the event of a fault. Modern installations are increasingly being built as gas-insulated switchgear (GIS), as they are space-saving and particularly reliable. This creates a compact and high-performance infrastructure at each site.

The most important components include:

For conversion between voltage levels.

Connected Energy

Substations in the electricity grid: the link between voltage levels

Substations act as the link between the various levels of the electricity grid. In the transmission grid, electrical energy is transported over long distances at very high voltages – often via overhead lines, but increasingly also via underground cables. Transmission system operators ensure that the individual electricity grids remain stable and balanced.

At the network’s interconnections, substations feed energy into the next voltage level. They help to balance out fluctuations, distribute loads and coordinate the feed-in from different sources. Power stations, renewable energy plants and battery storage systems are connected to the electricity grid via substations, thereby feeding their electrical energy into the overall system.

The driving force behind the energy transition

Significance for the energy transition and a stable energy system

As the share of renewable energy grows, so too does the importance of high-performance substations. Wind and solar power plants often generate electricity in a decentralised and fluctuating manner – substations ensure that this energy is fed reliably into the grid. In combination with battery storage systems, generation and consumption can be better balanced, which contributes to a stable energy supply.

A modern substation is therefore a key component of a sustainable energy system: it enables the integration of renewable energy sources and ensures an efficient supply to industry and households.

From idea to installation

Planning, approval and construction of a new substation

Before a new substation can be built, careful planning and a comprehensive approval process are required. This involves considering the suitable location, the connection to the transmission grid and the requirements of the electricity network. The protection of local residents and nature conservation also play an important role – for example, with regard to noise levels from the technical installation. Well-thought-out planning ensures that the infrastructure can be operated safely, efficiently and in harmony with its surroundings in the long term.

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Our expertise

Substations from WT Energiesysteme – a focus on two voltage levels

110 KV substations At WT Energiesysteme, we have built numerous 110 kV substations – and we are constantly developing them further. At this voltage level, we connect wind farms and solar parks to the transmission grid and lay the technical foundations to ensure that electrical energy reaches consumers reliably. From the switchgear and transformer to the busbar, we plan and construct every component of the system with the utmost care.

380 KV substations WT Energiesysteme also sets new standards in the extra-high-voltage sector. We build 380 kV substations and continue to support these challenging projects from the planning stage right through to operation. At the 380 kV extra-high voltage level, electrical energy is transmitted over long distances via the transmission grid – every technical component counts here. With state-of-the-art switchgear, we ensure a stable and efficient energy supply.

Answers to your questions

Frequently asked questions about substations

A substation is an electrical installation within the electricity grid that connects different voltage levels. Transformers are used to convert electrical energy from one voltage to another. This enables electricity from power stations and renewable energy plants to be transmitted safely and made available to consumers.