Expansion of the power grids: electricity by overhead line instead of the earth cable? That would be the consequences

A lot of money could also be saved by conversion of earth cables to overhead lines when expanding electricity in Germany – consumers could also benefit from this. At the next three large planned new construction lines – Ostwestlink, Nordwestlink and Suedwestlink – at least 20 billion euros were saved, said Tim Meyerjürgens, CEO of the power grid operator Tennet, the German Press Agency.

“In the medium term, the network charges could be reduced by one cent per kilowatt hour,” said Meyerjürgens. “It is important to use every possibility to relieve industry, business and private households.” The network expansion is financed through the network charges, which also pay private consumers.

A spokeswoman for the Federal Network Agency said: “Expanding lines have undisputed cost advantages.” The potential savings on the new construction lines Ostwestlink, Nordwestlink and Suedwestlink would be around 16.5 billion euros. “However, a swivel for overhead lines would throw back the planning of this project, which was previously planned as an earth cable.” The power grid operator Amprion was cautiously expressed at an end to the end of the ground cable priority.

In the course of the energy transition with an expansion of renewable energies, thousands of new kilometers are to be laid in order to transport the wind power produced, especially in the north, into large consumer centers in the south. A priority of the ground cable has been in force for large “electricity highways” since 2016. It had been introduced by the then coalition of the Union and SPD to increase acceptance among the population for network expansion. The background was worried about “monster roads”.

In a paper, the transmission system operator Tennet, TransnetBW and 50Hertz states that the use of the ground cable generally did not result in the hoped -for greater acceptance. The three companies speak out for a change of course.

Coalition has announced Reform

The CDU, CSU and SPD coalition agreement states that the newly planned high-voltage equal current transmission networks (HGÜ) should be implemented “where possible” as overhead lines. “We will take particularly burdened regions into account.” These measures could make the network expansion more efficient.

A spokesman for the Federal Ministry of Economic Affairs and Energy said that the expected electricity requirement and the state of security, network expansion and the expansion of renewable energies should be checked as a basis for further work in a monitoring until the summer break in 2025. The findings would be taken into account in the decisions about future HGÜ and their design.

The chief of the fourth large power grid operator Amprion, Christoph Müller, said: “Before the debate about technologies, the question of need is for us. We should only build what we really need. The current development of the demand suggests that it is less than previously assumed.”

Furthermore, approval procedures have become faster, which also had to do with the priority of the ground cable. If these procedures took longer again, nothing was saved due to rising so-called so-called redispatch costs. This means compensatory measures against bottlenecks in the power grid, which are paid for via the network charges. “In this respect, it is dangerous to abolish the priority for earth cables without creating a new priority for overhead lines,” said Müller.

The so-called DC projects Ostwestlink, Nordwestlink and Suedwestlink were no longer included in the so-called federal requirements plan before the Bundestag election in February. The planning approval can therefore no longer be started by the EU emergency regulation by June 30, according to the Federal Network Agency. Accelerated approval procedures according to the emergency ordinance would therefore not be considered for these projects.

“We have long been calling for the ground cable to replace the ground cable for direct current projects with an overhead line,” said Meyerjürgens. “The restart of the approval procedures of central network expansion projects now offers the opportunity to change in time and consistently set over overhead lines instead of underground cables.”

It is about these projects

In the future, the Ostwestlink will transport green electricity from the coast of Lower Saxony to Saxony. The northwest link is to bring electricity from wind energy on land in Schleswig-Holstein and Lower Saxony as well as offshore wind power in the North Sea to Baden-Württemberg. The Suedwestlink is intended to increase the transmission capacity between Schleswig-Holstein and Southern Germany.

According to Tennet, the planning approval documents for all sections have been submitted to the Federal Network Agency for large lines such as the Suedlink from north to south, and the final management process is determined. In some places this has already been done, the construction work has started. Suedlink is planned as an earth cable project. In many places there are citizens’ initiatives against new electricity routes.

The spokeswoman for the Federal Network Agency said that so -called preference rooms had already been determined for the Nordwestlink and the Suedwestlink, which were designed for an earth cabling. “If a decision to switch to overhead lines, these preference rooms would be obsolete and would have to be completely newly determined for overhead lines.” This would result in massive delays.

Among other things, the power grid expansion is financed with the network charges. The fees as part of the electricity price have increased significantly in recent years. According to Tennet, a reduction in the network charges by one cent per kilowatt hour would mean to private households: a two-person household with an annual consumption of 3,000 kilowatt hours would save around 30 euros a year, with a consumption of 5,000 kilowatt hours it would be 50 euros a year.

Why overhead lines are cheaper

Overhead lines can be built much faster and cheaper than earth cables, as can be seen from the paper of the three transmission system operators. Each kilometer of earth cables instead of overhead line costs around 10 to 20 million euros more. According to Tennet, depending on the topographical conditions, the construction costs for overhead lines are a factor of four to eight cheaper than earth cables. In addition, according to paper, overhead lines are easier in operation and repaired faster.