Much of the current transmission grid in Norway is too weak to meet future needs for secure electricity supply. An important step towards the next-generation main grid is to increase the grid voltage from 300 to 420 kV, referred to as a voltage upgrade.
This will be done by converting existing 300 kV power lines and substations, or by replacing old low-capacity lines with new ones. In this way, the capacity of each line can be increased, with very limited reservation of new land.
Statnett views the upgrade as a technically sound and environmentally friendly solution that will renew the grid, increase capacity and reduce losses with little impact on the landscape. Statnett has therefore started planning the construction of a new 420 kV power line to replace the existing 300 kV power line between Klæbu and Aura.
The upgrade will be done by building a new power line to replace the old one, which will be demolished. This can be done by building a new 420 kV power line in the existing corridor in parallel to the existing line. Alternative routes are being evaluated for parts of the line to protect the environment and built-up areas.
The overall objectives of the voltage upgrade are:
- To facilitate planned renewable energy production in Central Norway and Nordland.
- Increase transmission capacity from north to south in Norway.
- Improve the security of supply in the region.