TenneT 150 kV high-voltage substation


As a national grid operator of the high-voltage grid, TenneT is responsible for guaranteeing the supply of electricity. In order to be able to guarantee this now and in the future, TenneT is working on various adaptations and extensions of the high-voltage grid to ensure that everyone in the Netherlands has electricity 24 hours a day, 7 days a week. On the grounds of the 150 kV high-voltage substation in Rijswijk, the existing station is being demolished and will be replaced by an entirely new one. It has not proved possible to renew or to replace the installation within the current high-voltage substation, and that is why the existing building will be replaced by a new station housing a new installation.

Because TenneT restricts its activities to core activities, the assignment has been put on the market as a Design & Construct contract (D&C), according to UAV-GC-2005 (Uniform Administrative Conditions for integrated contracts), as a result of which Volker Energy Solutions BV was chosen as Contractor. KH Engineering has a framework agreement with VES for the purposes of engineering services and this marked the beginning of cooperation on this project.


A new 150 kV switching station, including a cable basement, must be realised on the existing grounds of the substation in Rijswijk for the purpose of setting up a new, modern Gas-Insulated Switchgear (GIS = a sizeable gas-insulated switchgear measuring approx. 20.00 x 4.00 x 3.00 m1), including expansion possibilities for three additional switching fields. A design is also required with a clearly sustainable character, according to the IFD principle. (IFD stands for Industrial, Flexible, Demountable).

Requirements with regard to sustainability, flexibility, speed of building and reuse are achieved through the construction method used. This construction method is based on the use of prefab concrete elements, of both outside and inside walls and demountable steel supporting constructions. The D&C contract, in combination with the early input of subcontractors has led KH Engineering to decide to design a 3D environment, based on Building Information Management (BIM) systems in which large and small prefab concrete elements, complex steel constructions, all structural facilities, the secondary installations and installations connected to the building are fully combined.


To avoid the D&C contract format resulting in (many) possible adaptations at the end of the design process, KH Engineering has introduced the 30%, 60% & 90% 3D model reviews. This method of project and design management was new to both VES and TenneT. All the parties have collaborated on the basis of this design vision and any possible doubts were soon replaced by enthusiasm and involvement. TenneT has announced through the project team that it will be introducing this method as a permanent procedure for future projects.

The professional approach by VES, responsible for the Primary and Secondary installations (read: 150 kV switchgear and security system), and the management of the system verification process has, as required by TenneT, resulted in a successful approach to the project.

Benefits to the client

KH Engineering executed this multidisciplinary assignment in close collaboration with VES and with the TenneT employees involved in the project. The introduction of our industrial approach to the project at TenneT was unique. The multidisciplinary design was developed into a 3D model by KH Engineering in such a way that the heart of the station, the GIS Installation, presents itself in accordance with future reality, in sky blue. Execution of the project was started in mid-2019 and will, partly due to the method of integrated design, be completed in the second quarter of 2020.

Projectleader: Patrick den Adel

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