Energy market

First ‘green’ Battery Storage in Europe

Together with DELTA Omexom realized the first Battery Storage in Europe for the American company AES. The storage is located in the Sloegebied, the port area on the East side of Vlissingen. In the 10MW Battery Storage, electricity is stored in Lithium-Ion batteries and forms a primary reserve for TenneT. The storage serves as a buffer to handle variations in electricity needs. This includes frequency control, which should be at a constant 50 Hz. No fossil fuels are used, so no polluting emissions occur. This ‘green’ solution puts AES in a leading position in Europe.


Omexom was responsible for the complete low voltage and building bound installations. This included e.g. installing the batteries, stacking them in racks and linking them to transformers. Omexom also installed a powerful cooling installation. This is very important because batteries produce a lot of heat. The battery storage has a capacity similar to 400,000 mobile phones. Also the commissioning was part of the job.


The Battery Storage is capable of balancing energy needs in the grid. AES uses the battery storage to instantly deliver power to the local and national electricity grid. The Advancion software of the Battery Storage continuously monitors the performance of the system as well as the supply and demand on the grid. The Battery Storage can respond to the changing needs of the electricity grid in less than a second. On the primary reserve market, the system competes with traditional power plants with the advantage that it doesn’t produce polluting emissions.

Realization Gemini offshore wind farm

In the Dutch part of the North Sea one of the largest wind farms in the world ‘Gemini’ was built. TenneT has awarded a part of the project to Omexom. Omexom was responsible for the final design, implementing the design (detailed engineering), the planning and the implementation.


The Gemini wind park is situated 85 km above the coast of Groningen and is built on two nearby locations. That’s where the name (Gemini-twins) is derived from. Gemini has a capacity of 600 MW and produces 2.6 TWh of electricity. It is one of the most productive wind farms in the world. The wind farms are connected to a high-voltage station on the mainland realized by Gemini. From this high-voltage station Gemini built a cable connection to the 380 kV high-voltage station Eemshaven Oudeschip.

TenneT, transmission System Operator and administrator of the national grid and owner and operator of 380 kV high-voltage station Eemshaven Oudeschip (EOS380), undertook the extend of the station by connecting the cable from the Gemini  high-voltage station to the 380 kV on the high-voltage grid. An extra field was added to the EOS380 station.


TenneT decided to tender this order to Omexom by a Design & Construct (D&C) contract according to UAV-GC 200. The overall coordination in relation to the end customer as well as the management supplies are oursourced to Omexom. Meanwhile the project is completed satisfactorily within the time limit, in september 2015.

Omexom helps reinforce electrical power transmission between Belgium and the Netherlands

In Belgium, there is concern about energy supply security. The closure of two nuclear power plants in 2016 only increased these concerns. Belgium’s own production capacity is insufficient, making import necessary. Extending the existing interconnection capacity with the Netherlands forms one part of the solution. It also represents a fresh move towards greater integration of the northwestern European energy markets. Interconnector Zandvliet is one such connection between the Netherlands (Borssele and Geertruidenberg) and Belgium (Zandvliet). The capacity of this connection needs to be increased considerably.

What was the question?

TenneT asked Omexom to take on the engineering and realisation of substations in Borssele and Geertuidenberg. The assignment also involved the writing of testing and commissioning plans. The major challenge here was that the whole conversion needed to be completed within two days. Henrie Sanders, Project Manager at TenneT: “The 380 kV connection is important to the business operations of both TenneT and Elia. This means that the decommissioning time needs to be kept as short as possible and that in the event of a technical fault, we need to be able to revert to the initial situation whenever necessary. A good design, sound preparation and planning are a crucial part of this.”

What was the outcome?

Henrie Sanders goes on to say: “For the conversion itself, Omexom drew up an extensive plan and roadmap which included contingency plans for a possible reversal scenario. Thanks to Oxemom’s contribution and effort, the project was successfully completed within the prescribed period.” In Belgium, they are another step closer to bringing the security of supply to the required level so that our southern neighbours can relax in the knowledge that they can rely on the power grid.