Sustainable energy supply for Windpark Geldern

The Geldern wind farm uses a solution from Ormazabal for its primary grid connection, including an F-gas-free medium-voltage switchgear. 

Ormazabal’s new SF6-free technology is being used for energy distribution at a new wind farm in Geldern, North Rhine-Westphalia. The F-gas-free sbp.zero24 medium-voltage switchgear for the primary distribution level up to 24 kV is compatible with the cpg.0 lite switchgear type and is used alongside it in the transfer station at the grid connection point for the wind farm. 

Grünwerke GmbH implements renewable energy projects throughout Germany. Grünwerke has erected two wind turbines in the Geldern area, which feed green electricity into the grid. The cable lines for the wind farm’s electricity connection stretch from Steprather Heide, not far from the Dutch border, to the grid connection point in Kevelaer, approximately seven kilometres away. In order to connect the grid to the substation in Kevelaer, a transfer station and a power transformer were required. Here, the energy generated by the wind turbines is transformed from 20 kV to the grid-compatible voltage level of 10 kV and then passed on from the switchgear to the substation for further distribution. 

Heading into the future together 

Our partner, the energy infrastructure service provider Omexom Elektrobau GmbH, was commissioned to plan the innovative medium-voltage infrastructure for the project, which will have a future annual energy yield of approximately 32 GWh. For the grid connection, Omexom supplied a 20 MW power transformer in a special enclosure and a transfer station with a 10 kV and a 20 kV switchgear, which was planned and successfully implemented in close cooperation with Ormazabal.  

Customised solution from Ormazabal 

The medium-voltage switchgear we supplied consists of a 10 kV feed-in section with two cpg.0 lite-v circuit breaker panels and a 20 kV section with a cpg.0 lite-s riser panel and a cgm.3-ma metering panel. The supply transformer integrated into the metering panel ensures the station’s own power supply. 

Thomas Höfkens, Solutions Manager at Ormazabal Germany, explains: ‘Transfer stations now have increasingly higher self-consumption requirements. Our metering panel can be equipped with transformers of up to 5 kVA. This solution is unique and can easily meet the requirements of this station.’ 

An F-gas-free circuit breaker panel of the type sbp.zero24-v is used for the output to the wind farm. The new SF6-free solution from Ormazabal is compatible with our cpg.0 lite system type. This means that systems can be expanded with F-gas-free technology in the future if required. 

Ormazabal supplied all secondary technology, which was individually selected in accordance with Omexom’s requirements and the technical connection conditions of the responsible grid operator Westnetz GmbH. The parameterisation and protection tests in accordance with VNB specifications were then carried out by Omexom’s protection engineers. The protection technology includes a short-circuit direction and earth fault direction indicator in the feed-in panel, a distance protection relay in the transfer panel and an outgoing protection relay in the outgoing panel. The components ensure safe operation and reliable grid monitoring. 

The wind farm has been connected to the grid since July 2025 and will supply up to 9,000 households per year with green electricity. A key factor in the successful implementation of the project was the detailed engineering work carried out to meet the specific requirements for primary distribution. 

The system complies with the characteristics required by the tender for a rated voltage of 10 kV and 20 kV with a rated operating current of 1,250 A. ‘Close coordination between Omexom and Ormazabal made it possible to find the ideal solution for the project in Geldern,’ explains Viktor Kamperdick-Voß, Project Manager for Energy Technology at Omexom Germany. ‘The precise, joint planning and smooth communication are particularly noteworthy,’ says Kamperdick-Voß. 

F-gas-free sbp.zero24 switchgear 

‘In addition to several cpg.0 lite switch panels, an sbp.zero24 outgoing panel is also installed in the project,’ emphasises Thomas Höfkens. The new SF6-free switchgear used in the project is our next generation of innovative switchgear for medium voltage. The sbp.zero24 is based on the industrial natural air insulating medium and therefore does not require F-gases. The solution for primary distribution is based on proven vacuum technology and is completely gas-insulated. ‘The compatibility of the sbp.zero24 with our SF6 gas-insulated cpg.0 lite switchgear for the primary distribution level up to 24 kV and 1250 A / 25 kA ensures that both systems interact seamlessly with each other,’ says Thomas Höfkens.  

For the end customer Grünwerke, a subsidiary of the public utility Stadtwerke Düsseldorf AG, the project marks a milestone: it is the first time the company has used an SF6-free switchgear. ‘For us, this is a significant step and a valuable opportunity to gain experience with this future-oriented technology,’ emphasises Marc Ostendorp, project manager at Grünwerke. 

Cooperation that works 

One of the main criteria in selecting the supplier was compliance with the delivery date requested by Grünwerke. Omexom chose Ormazabal as partner for medium-voltage technology because of our customised solution, fast delivery times and reliable support in planning, installation and commissioning. 

“Ormazabal provided comprehensive training for the operating personnel on how to use the new type of system. As this is not a simple standard system, but a solution tailored to the project, the technicians had a number of questions about the installation of the switchgear. These were answered quickly and competently at all times by Ormazabal’s Solutions Team,” explains the Energy Technology Project Manager at Omexom Germany.  

The project at the Geldern wind farm demonstrates how innovative technology and close cooperation between partners can help to create a sustainable solution for energy supply. The use of an F-gas-free switchgear ensures both more environmentally friendly energy distribution and a reliable, long-term infrastructure. Together with Omexom and Grünwerke, we are making an important contribution to the energy transition – with a solution that is both ecologically and technically future-proof.