After around four years of intensive project work, it’s finally ready – the updated multi-year plan for the expansion of the Swiss transmission grid. Using simulations and analyses, Swissgrid’s experts have identified 31 key grid expansion projects to prepare the transmission grid for future requirements. Project manager Marc Vogel evaluates the results.
Interview
The planning phase for the grid of the future is complete. What are the most important findings in your opinion?
Marc Vogel: The updated grid development requirements confirm the grid projects we have already initiated. Their rapid implementation remains a top priority. Our simulations and analyses show that new power plants, storage facilities and consumers with a connected load of several hundred megawatts, such as large data centres and battery storage systems, pose a particular challenge for the transmission grid – or more precisely, for the relevant connection point. In contrast, Swissgrid’s transmission grid has been robustly designed to meet the additional requirements resulting from the decentralised expansion of photovoltaics and electromobility. The transmission grid needs to be enhanced due to the widespread distribution of large wind farms, solar plants, consumer centres and storage facilities in Europe. Another finding is that the grid needs to be developed, operated and maintained in a comprehensive and coordinated manner across multiple voltage levels.
Can you elaborate?
If the infrastructures of different operators – including Swissgrid, the distribution system operators and Swiss Federal Railways (SBB) – are bundled, this has several advantages. It reduces the impact on the landscape and increases security of supply by dividing the grid operators’ parallel systems between different routes. That’s why Swissgrid is initiating more and more regional grid coordination projects and grid studies in order to jointly develop the best possible solutions for the grid of the future.
The transmission grid needs to be enhanced due to the widespread distribution of large wind farms, solar plants, consumer centres and storage facilities in Europe.
Marc Vogel
Which transmission grid projects are particularly important for the grid of the future?
Firstly, the grid projects to strengthen the north-south axis by expanding the grid from Germany (Tiengen) via central Switzerland as far as Ticino (Magadino). The second group of important grid projects are the projects that will enable us to improve the connections between the large production plants in the Alps and the consumer centres in Central Switzerland. They include the Bickigen – Mettlen line over the Gemmi Pass to connect the greater Bern area with the Valais. The third group of strategically important projects are the projects that will connect Ticino to the rest of Switzerland more effectively while also strengthening east-west transport capacities. We will achieve this by expanding the lines between the Valais and Ticino via the Nufenen Pass. Last but not least, the 21 new adjustable transformers distributed throughout Switzerland represent a major step forward: they will improve the controllability of the grid.
What role do adjustable transformers play in the electricity system?
Electricity always takes the path of least resistance. The load on the line with the lowest resistance is increased as much as possible, which then causes congestion for the entire system: even if parallel lines still have free capacity, no more electricity can be transported. Adjustable transformers change the resistance of the connected lines. They distribute the electricity flows more evenly and increase the transport capacity of the system as a whole.
Last but not least, the 21 new adjustable transformers distributed throughout Switzerland represent a major step forward: they will improve the controllability of the grid.
Marc Vogel
What are the next steps in the process to develop the grid of the future?
Swissgrid will now discuss the grid development requirements that have been identified and confirmed (by the regulator ElCom) with the operators of neighbouring grids to harness synergies and determine the ideal joint grid topology. The next steps are project planning and the approval process and, once these stages have been successfully completed, project implementation. The entire process currently takes an average of 15 years per grid project – although the exact length depends on the objections raised. The political and social will of all those involved is needed to reduce the number of objections and speed up the processes. Because one thing is clear: grid expansion must be accelerated.
At European level, a «supergrid» is being created to transmit large volumes of electricity over long distances. How is Switzerland involved in this project?
Swissgrid has launched a grid study with a German transmission system operator and its Italian counterpart. The aim is to analyse how Switzerland can be integrated into the planned additional direct current high-voltage grid and with what capacity. This integration promises to be a win-win situation. Switzerland has flexible pumped storage power plants, while Germany and Italy have large solar and wind energy plants with huge production fluctuations. This makes collaboration an obvious choice.
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