Statnett is in the process of building its next-generation main grid. An important step towards the next-generation main grid is to increase the grid voltage from 300 to 420 kV (voltage upgrade). This will be done by converting existing lines and 300 kilovolt substations, and by replacing some old and weak lines with new ones. In this way we can increase the capacity of each line, without using new routes. This will contribute to the production of more renrewable energy.