The grid and secure grid operations are fundamental prerequisites for prosperity and high quality of life in Switzerland. From healthcare and business to individual households, our modern society depends on electricity being available at all times, even in the most remote locations. The grid enables the electricity that is produced to be used everywhere, around the clock, by connecting all power plants, storage facilities and consumers. The Swiss transmission grid, which is like a network of «electricity highways», has an important role to play. As the backbone of a secure supply of electricity, it makes a key contribution to achieving the goals of the Energy Strategy 2050.
The grid concerns us all
Switzerland’s electricity system is in the midst of the greatest upheaval in its successful history. Energy reform brings with it a paradigm shift from a centralised to a decentralised energy system. Increasingly volatile utility power generation due to the growing share of renewable energies (photovoltaics, wind power), electricity storage in batteries and pumped storage power plants, as well as the rise in consumption due to e-mobility, heat pumping technology and data centres, result in additional challenges for secure grid operation. This has far-reaching effects on the electricity industry in Switzerland and throughout Europe, and therefore also on the Swiss grid.
Grid planning with foresight
Modernisation of the transmission system lays the foundations for a sustainable energy future. Its conversion and expansion has slowed down in recent decades. Only one-third of Swissgrid’s 6,700-kilometre transmission system dates from after 1980. Current congestion, as well as any future threats of congestion, must be eliminated to guarantee the safe, powerful and efficient operation of the Swiss electricity system.
The grid must continue to be developed
The requirements placed on the grid have changed significantly in recent years. This trend will intensify in the coming decades with the energy transition. While hydropower remains central in Switzerland, nuclear power plants are gradually being taken off the grid. They are being replaced by many new decentralised energy sources and power plants (photovoltaics, wind power) that are being connected to the grid throughout the country. In addition, electricity consumption will grow significantly in the future due to decarbonisation.
The transmission system must be developed in the long term to ensure that it can meet future needs for a secure supply of electricity. Swissgrid periodically draws up a multi-year plan for this purpose: the Strategic Grid.
The Strategic Grid 2040 is the third coordinated process for the further development of the Swiss transmission grid. For the first time, it takes into account the legal basis established in the «Electricity Networks Strategy». According to this basis, the planning process must be repeated in a comparable manner every four years. The first two projects to determine the Strategic Grids 2015 and 2025 differed significantly from the current solution.
In 2008, the planning process for the Strategic Grid 2015 was carried out separately by the former eight owners of the transmission system. In 2015, Swissgrid planned the Strategic Grid 2025 on its own. At the time, Swissgrid created the scenarios itself. This will be a task for the Swiss Federal Office of Energy (SFOE) for the first time for the Strategic Grid 2040.
The «Strategic Grid 2025» includes ten projects. The defined projects are all in various stages of implementation.
In the planning phase of the grid development process, the Swiss Federal Office of Energy (SFOE) drafts an energy policy scenario framework for Switzerland. It is approved by the Federal Council and used as the future basis for planning the Swiss electricity grid – with the aim of ensuring that the electricity grids are optimally aligned with the future energy policy developments in Switzerland. The scenario framework contains three scenarios that reflect the range of possible energy policy developments.
Swissgrid then uses this scenario framework to determine the need for adjustments to the transmission system. These changes are documented in a multi-year plan, the «Strategic Grid». Expansion planning for the distribution system operators’ high-voltage grids is also based on the scenario framework. The planning phase is repeated every four years, which means that the high-voltage grids (distribution system) and the extra-high-voltage grids (transmission system) can be continuously adapted to changing framework conditions in parallel and by mutual agreement.
In the project planning phase, Swissgrid develops specific projects covering the demand identified in the Strategic Grid report. Every project normally passes through a national sectoral plan process for transmission lines at the SFOE as well as a planning approval procedure with the Federal Inspectorate for Heavy Current Installations (ESTI). Decisions on the transmission technology to be used (overhead lines, cables or a combination of the two) and routing are also made in this phase.
Once all the necessary approvals are in place, Swissgrid starts the implementation phase with the construction of the relevant projects. After commissioning the installations, Swissgrid also checks whether the project costs assumed in the Strategic Grid and their expected benefits reflect reality and possible reasons for deviations. The findings from these analyses are incorporated into the recurring planning process.
Swissgrid is not expanding the grid to accumulate reserve capacity. The existing grid is operated as efficiently as possible. Wherever possible, Swissgrid first optimises the existing grid and enhances it as necessary. Obsolete lines and substations are dismantled wherever possible. If a new line is required, Swissgrid takes into account the spatial and environmental impact, as well as technical aspects and cost-effectiveness, when searching for the best line corridor and selecting the transmission technology (overhead line or cabling).
The bundling of transmission lines with trunk roads and railway lines reduces the number of parallel routes. The need for expansion between grid nodes is determined as part of the Strategic Grid. The line corridor and transmission technology are definitively determined within the framework of the subsequent «Spatial Coordination (National Sectoral Plan Procedure)».
Swissgrid identifies grid elements where congestion will repeatedly occur in the future. For this purpose, Swissgrid refers to findings from current grid operations as well as a grid simulation for the target year 2040. Existing and future congestion will be eliminated via grid optimisation, grid enhancement and grid expansion.
The dismantling of large power plants all over Europe reduces the rotating mass on the transmission system. The inertia of large generators, such as those found in nuclear or coal-fired power plants, still stabilises the frequency of the grid today. Swissgrid and foreign transmission system operators conduct stress tests to determine whether grid stability can still be guaranteed in the future or whether measures need to be taken as part of grid planning.
In grid planning, Swissgrid can only take into account the potential for flexibility offered by artificial intelligence, decentralised consumption control and smart peak shaving in photovoltaic and wind production if it can be activated and used by Swissgrid at any time. To achieve this, the regulatory framework conditions must be created, products developed and contracts concluded. This has not yet happened to a sufficient extent.
For every grid project costing more than CHF 1.0 million, Swissgrid carries out and documents a uniform cost-benefit comparison. The benefit of each grid project is shown in monetary, quantitative or qualitative terms according to various criteria.
Swissgrid coordinates long-term grid planning with all the relevant stakeholder groups. These include, for example, the transmission system operators of neighbouring countries, the distribution system and power plant operators connected to the Swiss transmission grid, the Swiss Federal Office of Energy (SFOE) and the Swiss Federal Electricity Commission (ElCom). Swissgrid communicates the procedure and results of the Strategic Grid in a transparent and comprehensible manner.
Opinions on the grid of the future
Safeguarding Switzerland’s energy future in a sustainable manner
The grid is the backbone of a secure supply of electricity in Switzerland. This means that far-sighted planning and development of the grid are in the interest of the national economy and the entire Swiss population. Business and political figures, as well as members of the population, explain why the grid is important in this context and for them personally. Because the grid concerns us all.
Strategic grid planning
As the backbone of a secure supply of electricity, the transmission system makes a key contribution to achieving the goals of the Energy Strategy 2050. To ensure that the transmission system meets future needs, Swissgrid periodically draws up a multi-year plan – the «Strategic Grid». This describes and justifies the planned grid projects for the target year. Swissgrid is currently planning how the transmission system will have to be developed by 2040 in order to meet future requirements.
The grid development process in Switzerland is governed by the provisions of the Federal Act on the Renovation and Expansion of the Grids («Electricity Grid Strategy»). The relevant provisions are found in particular in the Electricity Supply Act (Article 9a-d StromVG). These provisions have governed the grid development process in Switzerland since 2021.
Strategic Grid 2025 and 2040
Swissgrid had already developed a multi-year plan for the needs-based modernisation of the transmission system back in 2015, before the entry into force of the statutory provisions on the grid development process: the Strategic Grid 2025. The ten grid projects identified in it are essential for a secure and reliable Swiss transmission grid. They are at different stages of implementation. You will find an overview on our website Project overview.
Specific grid projects can only be defined once the «2030/2040» target grid has been formed at the end of 2023. First, Swissgrid will establish the start grid at the beginning of 2023, which includes all grid elements that will have been implemented and commissioned by 2030. The start grid represents the starting point. Based on the start grid, the «Reference grid 2030/2040» will be formed by means of market and grid simulations. It includes new grid projects determined in consultation with neighbouring transmission system operators and distribution system operators. Once this reference grid has been finalised, Swissgrid will form the 2030/2040 target grid. To do so, it evaluates the additional grid projects with the help of a cost-benefit analysis. Grid projects where the benefits outweigh the costs become part of the target grid and therefore of the Strategic Grid 2040. Swissgrid submits the strategic grid to ElCom for review. Swissgrid will then publish the Strategic Grid 2040 with the projects it contains, probably by the end of 2024. This process is to be repeated every four years on the basis of an updated scenario framework.
Scenario framework and regionalisation
The Scenario Framework Switzerland (SZR CH) was first adopted by the Federal Council in November 2022. It is an instrument that describes the various probable developments of the energy industry in the future – with a particular focus on grid planning. The energy policy goals of the federal government and developments in other European countries are taken into account. The SZR CH creates a uniform, binding basis for grid planning by the grid operators. Swissgrid was involved in the development of the SZR CH as a member of the monitoring group alongside other interest groups. The SZR CH will now be updated every four years.
The scenario framework describes a range of possible developments up to 2030 and 2040 in three scenarios. They differ partly in terms of the foreseen development of the installed capacity of power plants, storage systems and annual power consumption for different technologies or customer groups. Further information and the document «Scenario framework for electricity network planning» can be found on the SFOE website.
In addition to the scenario framework, further information is required for grid planning. This includes knowledge about the structure and renewal requirements of existing grids as well as the regional needs for connecting new power plants or end consumers. Planning must also consider cantonal structure plans, the plans of other infrastructure operators (bundling potential), the applicable grid planning principles and developments in neighbouring grids. In 2020, Swissgrid started working with the grid operators of grid level 3 to establish processes for the provision of data and regionalisation of the key figures contained in the scenario framework. This is part of the Swissgrid project «Strategic Grid 2040».
The regionalisation process involves determining changes per parameter (power plants, storage systems, consumers) in each grid node, i.e. at each point where power plants and/or distribution grids are connected to the transmission system. This process is carried out by the twelve distribution system operators connected to the transmission system in cooperation with Swissgrid.
By regionalising the development of generation and consumption described in the scenarios, a usable (i.e. node-specific) data basis is created for demand-oriented and resource-saving grid planning.