The grid concerns us all, but is also a complex topic – that makes it the perfect breeding ground for all kinds of myths. But are any of them true? It’s high time for a myth check...
Myth 1: Switzerland has a reliable electricity flow. The grid is in place and has been amortised. No major investments are needed.
Yes, they are. No electricity can flow without the grid. Around two-thirds of the Swiss transmission grid is now between 50 and 80 years old. An overhead line has a service life of around 80 years. It’s easy to calculate that we must maintain, modernise and expand the grid on an ongoing basis. But not only because of its age. The grid also needs to keep pace with the energy transition. We will need an efficient grid wherever we produce electricity in the future. This is the only way to transport the electricity generated by solar plants, wind farms and hydroelectric power stations to the places where humans and industry need it. We need to invest in our grid because we want to be able to continue to rely on a secure supply of electricity.
We need to invest in our grid because we want to be able to continue to rely on a secure supply of electricity.
Myth 2: First, we have to produce enough electricity. New transmission lines can then be built quickly or existing ones reinforced.
This is not possible with the current approval processes. Today, it takes around 15 years from the start of a project to the commissioning of a new line. Objections and court judgements often lead to significant delays in projects – so they can take up to 30 years. A production plant can’t supply energy to anyone if the grid capacities are not sufficient to transport the energy produced. To prevent the grids from becoming the bottleneck of the energy transition, it is crucial for grid expansion to keep pace with the expansion of renewable energies. The energy transition needs a strong grid. Approval processes must be accelerated.
The energy transition needs a strong grid. Approval processes must be accelerated.
Myth 3: The grid is being expanded to create advance capacity. This is unnecessary and expensive.
Just as there can be traffic jams on the roads, congestion can also occur in the grid. In the future, this type of congestion will mean that not all e-cars can recharge at the same time, for instance, or that solar plants can’t feed all of their electricity into the grid at specific times in the summer. To avoid congestion, Swissgrid plans for the long term and applies the NOVA principle. NOVA stands for «grid optimisation before grid enhancement before grid expansion» (in German). The existing infrastructure is being optimised and reinforced. Swissgrid only builds new lines where they are absolutely necessary. For example, to connect new production plants to the grid. This requires a robustly developed grid and clarity about how much power can be connected to which grid node. Swissgrid makes sure that this is the case in its strategic grid planning.
The existing infrastructure is being optimised and reinforced. Swissgrid only builds new lines where they are absolutely necessary.
Myth 4: Once the grid has been built, it is a sure-fire success that is financially worthwhile for the operators.
No, specialists at Swissgrid have to work hard on a daily basis to ensure a secure supply of electricity. The Swiss transmission grid must be maintained, modernised and expanded. This is the only way to ensure that it will remain one of the most reliable transmission grids in the world. Around 12,000 inspections take place each year, and regular maintenance work is carried out. Two-thirds of the Swiss transmission grid, which is over 6,700 kilometres long overall, dates from before 1980. The overhead lines are exposed to wind and weather, and in the mountains also to avalanches, debris flows and rockfalls. The transmission grid must be modernised and expanded on an ongoing basis. This is because the energy transition requires a change in the energy system. This applies to the grid, too – and this change costs money.
Myth 5: If overhead lines only have a service life of 80 years, then it would be better to lay the grid underground. This would make it less exposed to environmental influences.
Both technologies have their advantages and disadvantages. It is true that underground cables are less exposed to the weather than overhead lines. However, the service life of an underground cable in the transmission grid is around 40 years, which is half that of an overhead line. Underground cables have to be replaced more often and are between two and ten times more expensive to build. These additional costs for underground cables are borne jointly by all electricity consumers. While for lower grid levels, underground power lines are the standard and overhead lines are an exception, the opposite is true for the transmission system. At extra-high-voltage level (380 kV and 220 kV), electricity is currently predominantly transported using overhead lines. They make up 99 percent of the Swiss transmission grid and have proven their worth. In recent years, Swissgrid has installed underground cable lines with a total length of over 40 kilometres in the transmission system. The use of underground cables in the extra-high-voltage grid is comparatively new, and experience in the field is relatively limited. Due to their physical properties, underground cables have an impact on the stability of the entire transmission system. The greater the number of sections of the transmission system that are laid underground, the more the technical challenges increase.
These additional costs for underground cables are borne jointly by all electricity consumers.
Myth 6: Soon there will be no need for a grid. Thanks to solar panels on roofs, we will all be able to produce our own electricity.
On the contrary. The electricity produced in people’s homes is not always consumed there. Many solar power producers feed their electricity into the local distribution grid. This is especially true when the sun shines for long periods and the system produces more electricity than is consumed locally. What is more, when local electricity production from solar and wind power plants is low, electricity has to be transported to consumers from more distant power plants or storage facilities. This is another reason why the grid remains so important. Complete self-sufficiency, i.e. a supply of electricity without a grid, would only be achievable at a very high cost and with major restrictions in terms of comfort. This is because solar plants produce too little electricity in the winter and too much in the summer. Seasonal balancing is a major challenge.
Blog: The grid must always be taken into account when installing a solar plant
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