The SuedLink grid expansion project is a key component of the German energy transition for significant use and distribution of electricity generated from renewable sources. In this project, we are helping to build two high-voltage direct current underground cable pairs with a length of over 700 kilometers and a capacity of more than four gigawatts (two GW per cable system), primarily to transmit wind power from northern Germany to the south of the country. Theoretically, it will also be possible to transmit solar power north in the opposite direction. Responsibility for the project is shared equally by the two project promoters, TransnetBW and Tennet, with the first flow of electricity scheduled for 2028.

(Picture: TransnetBW SuedLink GmbH & Co. KG)

Motivation for the SuedLink Grid Expansion Project

The German transmission grid is being revamped due to the focus on renewable power generation in northern Germany through offshore and onshore wind farms, along with the simultaneous loss of generation capacity in the south due to nuclear and coal phase-out. Several direct current transmission line projects are currently being implemented throughout Germany so that the large distances between power generation and consumption can be bridged in future with as little loss as possible and in an environmentally friendly manner. One of these is SuedLink, which will transmit a total of four gigawatts of power at a voltage level of 525 kV using direct current technology by means of two parallel, point-to-point links over 700 km long from the Elbe to the Main and Neckar rivers. The expected capital investment for SuedLink including the four converter stations (two in the north and two in the south of Germany) is around 10 billion euros. This means that the SuedLink project is currently the largest infrastructure expansion project in Germany, if not in Europe.

This project is currently growing in importance, particularly due to the increased political significance of energy and the tense supply situation. The need for an independent energy supply in Germany through renewable energy sources has never been greater.

Fichtner’s Role in the Project

Since 2021, we have been supporting the project as a strategic partner of TransnetBW, the project promoter responsible for the southern part. In a joint interdisciplinary project team, spread over several subprojects, Fichtner currently has around 65 people assisting in the control and implementation of SuedLink throughout all its planning and implementation phases.

Along with our know-how that was a decisive factor in awarding the contract to Fichtner, an additional aspect came into play in the case of SuedLink, namely our familiarity with the German market and decades of experience and cooperation with German transmission system operators.

Since autumn 2021, Fichtner has been playing a key role in controlling the southern regional planning offices. Our efforts have, of course, been slowed down, as they have everywhere, by the Covid restrictions with countless MS Teams meetings between teams and people who had never worked together before and by the parallel mobilization of new hires into the Fichtner – but also SuedLink – world.

About half of the support we provide comes from our own staff, while the other half comes from partners or subcontractors. Due to scarce resources in this field and competing demand from our market competitors, as well as clients, our in-house contribution was initially limited. This prompted us to push ahead with our staff growth, resulting in us being able to recruit new team members in the double digits last year.

Nine Fichtner vehicles financed by the project are available to the project team in Göttingen and Würzburg for route inspections, ground investigations and other trips. Both locations have what we call regional offices, which are provided by the project promoters and serve as our contractual places of performance. The many kilometers needing to be traveled by road and rail are another challenge for our colleagues from Stuttgart and the surrounding area.

New Fichtner employees recruited for the Würzburg site (Picture: TransnetBW SuedLink GmbH & Co. KG)

Important project milestones have now already been passed. Federal sectoral planning (i.e. regional planning for projects under the German Grid Expansion Acceleration Act) has been completed. Now the planning approval documents need to be prepared and submitted in a similar fashion for the entire project so that the planning approval decisions can be gradually obtained for the various different sections. Technical aspects and preparations for the construction phase are also being handled, such as the logistical issues arising from transport of the cable segments that weigh several tons. One of the challenges in this respect is to find solutions for crossing roads, railways and waterways. It is precisely these significant and unique challenges for the Fichtner team involved and for the planner that make us particularly proud to be able to participate in this mega-project! Every project day presents new and exciting tasks, making it all the more fun to be part of the interdisciplinary team that is bringing this to fruition for TransnetBW SuedLink. Even though the road to realization of the project is long, we can already make a lot of difference with each additional milestone and make giant strides in advancing the energy transition.