- TenneT started the reinstallation of cables between the Borken and Mecklar substations with EQOS Energie in mid-April
- Challenging timeframe for the simultaneous realisation of two construction sections
- Close collaboration is an important contribution to strengthening and stabilising the energy supply in northern and eastern Hesse
: The existing 380-kilovolt (kV) overhead lines between the North Hessian substations of Twistetal, Borken and Mecklar and the Thuringia-based Vieselbach substation near Erfurt will be rendered fit for the challenges of the energy transformation. To reinforce this important East-West connection, the current-carrying conductor cables of the 380-kV circuits are being exchanged for so-called high-temperature conductors. . EQOS Energie, one of the leading service providers in the area of complex technical infrastructures, was commissioned by maximum-voltage network operator TenneT with two construction lots for the reinforcement of individual sections of the line from Borken to Mecklar.
More performant, more stable power grids
EQOS Energie will be responsible for replacing the conductors on a route stretch of more than 20 kilometres and for replacing the traverses, rehabilitating the foundations and raising the height of individual masts. “By upgrading to high-temperature conductors, potentially more electricity can be transported,” said Karl-Heinz Hüsing, head of the Germany South-West profit centre in Overhead Line Construction at EQOS Energie. “While the existing lines only heat up to a maximum of 80 °C, high-temperature conductors operate at a temperature of about 135 °C, which allows more current to flow. This renders the power grid significantly more performant and stable,” he explained.
However, to make this possible in the future, the client TenneT still has to go through some additional steps. . “The rewiring starting now in the Schwalm-Eder district and continuing towards Ludwigsau represents the technical basis for subsequent operation with increased current-carrying capacity. However, before the switch can actually be turned, a planning approval procedure must be carried out under the auspices of the Kassel Regional Council,” TenneT project spokesman Markus Lieberknecht said. TenneT plans to submit the application for planning approval in the coming weeks. After checking for completeness, the formal approval procedure can start. For this purpose, the planning documents will subsequently be made available to the public. Only after this procedure has been completed may TenneT use the line to a higher capacity.
Sustainable network operation takes centre stage
The rewiring will be implemented on the existing line, which is about 45 years old. New cable routing is not required. Project spokesman Lieberknecht: “We can design a sustainable grid operation in Hesse by reinforcing the existing grid for the energy transformation. This way, we can reduce new line construction and minimize the impact on people and nature. TenneT proceeds strictly according to the GORE principle, which means: grid optimisation prior to reinforcement prior to expansion.” With the measures described above, the contractual partners, EQOS Energie and TenneT TSO GmbH, are now jointly tackling this important conversion in northern and eastern Hesse from mid-April to autumn 2022. During this project, the tight TenneT schedule poses the greatest challenge for the EQOS Energie specialists. Hüsing: “TenneT must maintain the power supply via the highly utilised 380-kV line even during the construction stages. As a result, individual circuits can only be disconnected in stages. This means that we can only work in clearly defined, exactly scheduled time windows.” In order to complete the contract on time, EQOS Energie has two teams of 25 members each working for TenneT in the coming months. The contract amount is in the low double-digit millions.
Photos: Tennet