The Substation – The Electricity Network's Vital Junction

In our modern society, substations are becoming increasingly important. They constitute the very backbone of our electrical system, and their significance grows as society becomes more electrified.

When electricity is transported over long distances, it is most efficient to do so at high voltage. This reduces energy losses along the way. However, the high voltage used for long-distance transport (often 130,000 to 400,000 volts) would be lethal and impractical for use in our homes, where we use 230 volts.

This is where substations come into the picture. They "step down" the voltage in several stages:

• From the very high voltage of the national grid to regional networks
• Further down to local distribution networks
• Finally, to the low voltage we use in our homes and workplaces

Substations have several critical functions in the electrical system:

1. Interconnection of different networks: The substation connects different parts of the electricity grid and enables the transfer of electricity between different areas.
2. Monitoring and control: Modern substations are equipped with advanced measuring equipment and control systems that monitor electricity flow and can limit or redirect it when necessary.
3. Safety: The substations contain important safety systems that protect the electricity network from overload and other disturbances.
4. Flexibility: Substations provide the ability to distribute electricity to where it is needed most, which is particularly important when integrating renewable energy sources such as wind power and solar energy into the system.

Substations are part of the critical infrastructure that keeps our society functioning around the clock, year-round. They stand there in all weather conditions, often unnoticed but always necessary. Many of our substations, however, have several decades behind them – some were built during the 1960s and 70s when electricity needs looked completely different.

The dimensioning from that era is insufficient for today's society, where each household has considerably more electrical appliances than before. The increasing number of electric cars, heat pumps and other electricity-intensive equipment in homes means that the load on our substations is increasing dramatically. In some areas, capacity shortage is already a fact, which can lead to limitations in the electricity network and, in the worst case, power cuts.

At the same time, the increasing proportion of renewable energy places new demands on substations. Unlike traditional electricity production, solar and wind power vary depending on weather conditions, which requires smarter and more flexible substations that can handle these variations.

This ageing infrastructure now requires extensive renovation and modernisation. It's not just about replacing old components but also about making the substations smarter and more adaptable to meet future needs.

Investments in substations are therefore not just a technical necessity but a societally critical priority. They are the key to a successful green transition and a reliable electricity network that can meet tomorrow's needs. Without these upgrades, electrification risks being slowed down, which would hinder the climate transition and the digital development that our society is so dependent upon.