Project examples 2013

Voltage increase of the HV lines of Statnett in Norway

Norway´s energy distribution company, Statnett, is currently engaged in the largest voltage increase project on an electrical system that has ever been performed in the world. The company’s research has shown that the voltage can be increased by almost 30% on the current 300 kV high voltage transmission lines in the country instead of constructing new 420 kV lines. This action means that it is possible to save NOK 7bn in the upgrade of Statnett’s electrical system to 2030. Thereby it is possible to respond, in a relatively short time, to a significant increase of energy demand in Norway.


Mannvit, together with the engineering firm Ramböll, signed a framework agreement with Statnett last year. Mannvit is part of a team of three Statnett consultants that are working on the voltage increase on approximately 1500 km of electricity lines. The existing towers and conductors will be used. The design of the uprated line is divided into three parts: First the existing line is analysed and a model of it created that is as accurate as possible. The second phase comprises a first proposal for uprating using deterministic methods and the identification of ‘problem’ towers. Finally, the third phase involves a more detailed design, including fine-tuning and accurate engineering using probabilistic methods and final implementation.


Before implementation, the consultants, in co-operation with Statnett, will be responsible for the purchase of materials and follow-ups of material orders together with the preparation of specifications prior to implementation. The consultants will also be responsible for providing consultancy services during the implementation period, on-site follow-ups and the preparation of a final report on the project.

“It is a unique opportunity to be a part of the most extensive voltage uprating project in the world. We are following untrodden paths in the upgrade of the current high voltage transmission lines and significantly increasing transmission capacity at relatively low cost.“

Daníel Scheving Hallgrímsson

Project Manager