Industrial Decarbonisation: Tennet Commissions New 380 kV Line for Low-CO2 Steel in Salzgitter

Salzgitter – Transmission system operator Tennet Germany has commissioned a new 380 kV industrial line for the Salzgitter steel site. The extra-high-voltage line, around 11 kilometres long, adds grid capacity for the decarbonisation of steel production and strengthens regional power supply.

The transformation of energy-intensive industries is placing new demands on power grids. In particular, the switch to electricity-based steelmaking processes requires additional grid capacity. Alongside the expansion of long-distance transmission grids, high-capacity connections for large industrial sites are therefore becoming more important.

Salzgitter Industrial Line: 380 kV Grid Connection Delivered in Five and a Half Years

The new Tennet line connects the Liedingen switchgear with the Bleckenstedt/Süd substation via a 380 kV overhead line. According to Tennet, the existing 220 kV grid would no longer have been able to meet the foreseeable increase in electricity demand in the long term.

Planning for the new line began in May 2021, construction of the substations in September 2023 and construction of the overhead line in April 2024. The planning approval decision was issued in February 2024. In total, around five and a half years passed until commissioning in October 2026. Tennet attributes the comparatively short implementation time to good cooperation between grid operators, industry, authorities and policymakers.

Tennet CEO Tim Meyerjürgens sees the project as an example of accelerated grid expansion. “This pace, reliable framework conditions and the shared will to move projects forward must also become the benchmark for other important infrastructure projects in Germany,” said Tim Meyerjürgens, CEO of Tennet.

The new line is part of the Ostfalen axis, which is around 100 kilometres long and runs between Mehrum near Peine and the state border with Saxony-Anhalt. In the grid development plan, the Liedingen–Bleckenstedt/Süd section was designated for earlier implementation ahead of other grid measures because of rising electricity demand from regional steel and battery production. The remaining sections are still in planning or permitting.

At the Bleckenstedt/Süd substation, Tennet’s extra-high-voltage grid is connected to the regional distribution grid of Avacon. The additional infrastructure therefore also serves regional power supply.

SALCOS: Steel Production to Emit Less CO₂ With New Plants From 2027

The new grid connection is of particular importance for Salzgitter AG’s SALCOS transformation programme. The steelmaker is gradually converting its previously coal-based production to lower-CO₂ processes. Key elements are the direct reduction of iron ore and the further processing of the sponge iron in electric arc furnaces.

According to the company, the first SALCOS expansion stage is due to start production in the first half of 2027. The start of production, originally planned for the end of 2025, has been postponed several times. The new industrial line is therefore already available ahead of the planned commissioning of the production plants.

The changeover fundamentally alters the energy supply of the steel plant. While direct reduction can initially also use natural gas, the electric arc furnace requires large amounts of electrical energy. According to its 2025 annual report, Salzgitter expects additional electricity demand of around 2 TWh per year in 2028.

In addition to sufficient grid capacity, the company needs large volumes of low-CO₂ electricity. Salzgitter is relying, among other things, on long-term power supply contracts with energy companies.

Industrial Electrification Raises Requirements for Grid Expansion

The electrification of industrial processes and the replacement of fossil energy sources are changing the regional distribution of electricity demand. As a result, requirements are rising both for long-distance transmission grids and for the connection capacity of large industrial sites.

The scenarios of the transmission system operators approved by the Federal Network Agency show the scale of possible additional electricity demand. The 2025–2037/2045 scenario framework assumes industrial electricity consumption of 256.0 to 295.1 TWh in 2037. For 2045, the range is 260.0 to 354.5 TWh.

According to the Federal Environment Agency, industrial electricity consumption stood at around 186 TWh in 2024. The figures are only comparable to a limited extent owing to differing statistical definitions. The scenarios describe possible developments, not binding consumption forecasts.

Salzgitter illustrates the importance of aligning the timing of industrial transformation and grid expansion: the additional grid capacity is in place ahead of the planned start of production. However, the comparatively short implementation time of the brought-forward section, around 11 kilometres long, cannot easily be transferred to larger grid expansion projects.

Source: IWR Online, 28 Oct 2026