The electricity connections between Smestad and Sogn substations are so old that they need replacing to ensure a reliable supply of electricity to residents in Oslo in the years to come. The two earth cable connections, which date from 1955 and 1977, must be replaced in a few years. Statnett is now assessing possible solutions.
Test drilling is necessary to examine the soil conditions for a possible trench or tunnel solution. Drilling started on 19 June 2014 in the Makrellbekken stream, near Smestad substation. Drilling will take place in four other areas between Smestad and Sogn in Oslo. According to the schedule, the sounding between Smestad and Sogn will be completed around 4 July.
A small drilling rig is used for the test drilling and the hole that is drilled has a diameter of approximately five centimetres. The hole is filled in again afterwards. Norconsult Fältgeoteknik conducts the drilling and it may cause some noise.
When the assessment work has been completed, Statnett will apply for a licence from the NVE for the Smestad-Sogn interconnector. This is scheduled to take place over the course of 2014. As part of the NVE's licensing process, a consultation will take place, where all affected parties will have an opportunity to provide comments. Licences for the energy sector are considered in accordance with the Norwegian Energy Act.
The current owner of the Smestad-Sogn cable interconnector is Hafslund Nett AS. Once the new interconnector is in place, it will be owned by Statnett as part of the main grid.