Salzgitter AG supplies steel for 36 wind towers of the new offshore wind farm ‘Thor’ to Siemens Gamesa

• First major offshore wind project with the use of ‘green’ plates
• Production of the steel for the ‘Siemens Gamesa GreenerTower’ in 2025

Ilsenburger Grobblech GmbH, a subsidiary of Salzgitter AG, and the wind turbine manufacturer Siemens Gamesa have signed a contract for the delivery of around 25,000 tonnes of heavy plates for the construction of 36 wind towers. These wind towers are the so-called ‘Siemens Gamesa GreenerTower’.
 
The special feature of this tower is its CO₂eq emissions of less than 700 kg per tonne of steel. This is a significant step for the industry, as the production of wind towers alone is responsible for more than two thirds of all CO₂eq emissions from wind turbines. The new CO₂eq-reduced tower has been part of Siemens Gamesa's product portfolio since 2024 and can be used as an option for all future onshore and offshore wind turbines. The first use of the Siemens Gamesa GreenerTower is now the offshore wind farm ‘Thor’ in the Danish North Sea on the west coast of Jutland, which is planned to be completed by the end of 2027 and has a planned capacity of more than 1,000 MW. This will make ‘Thor’ Denmark's largest offshore wind farm to date with a total of 72 wind towers, which will supply more than one million Danish households. The wind farm is operated by the energy supply company RWE.
 
The heavy plate for the 36 ‘GreenerTowers’ will be supplied by Ilsenburger Grobblech GmbH (ILG) and Mannesmann Grobblech GmbH (MGB). ‘We are delighted that ILG and MGB are the first certified suppliers to make a significant contribution to reducing the global CO₂eq footprint by supplying low-emission heavy plate. To this end, we have invested in new equipment to be able to supply such wind projects with 18 - 24 meter long plates. This includes, for example, the investment in the transport line for finishing with an overhead crane and a mobile roller table extension,’ says Oliver Laubner, Sales Manager at Ilsenburger Grobblech GmbH.
 
’It is a pleasure to see the first GreenerTowers taking physical shape in the real world – not only as drawings. The energy transition demands end-to-end value chains working together to eliminate CO₂eq emissions. GreenerTowers exemplifies this collaboration. If all towers installed by the company in one year were replaced with GreenerTowers, it would be equivalent to removing over 466,000 cars from European roads for a year. Innovations like this are crucial to achieving our sustainability goals’ states Maximilian Schnippering, Head of Sustainability at Siemens Gamesa.
 
Around 30,000 tonnes of primary material are required to produce the heavy plates. Some of these slabs are produced with low CO₂eq emissions at Peiner Träger GmbH (PTG) using scrap-based electrical steel and renewable energies. The remaining slabs are supplied by our international trading company Salzgitter Mannesmann International from European sources with similar low CO₂eq emissions.
 
The heavy plates for the wind towers are to be delivered to the wind tower manufacturers Windar in Spain and Welcon in Denmark from March to October 2025.