Maintenance of the national grid
Svenska kraftnät needs to maintain the national grid lines and stations regularly. This is important to ensure the supply of electricity.
Maintenance can be anything from reviewing the physical equipment on the lines and in the national grid stations, to clearing or felling tall vegetation along power line corridors. Svenska kraftnät hires contractors to carry out maintenance work.
Tree clearing in the power line corridors
The area under a power line is called a power line corridor. In woodland this consists of a forest corridor with side areas. The side areas are often approximately 10 meters wide. The width varies depending on the terrain and on how the line is designed.
In forest corridors we clear away all the tall trees and shrubs. The trees and shrubs that do not grow that tall, such as junipers, are left behind if they do not interfere with our supervision of the line or risk damaging the line in any way. By clearing the forest corridor it can also be used as a road for forestry equipment when the line needs to be serviced or repaired.
Outside the forest corridors, in the side areas, certain trees are felled that may fall over and damage the lines. We call them "dangerous trees".
Clearing occurs regularly
Every year we conduct an inspection of the lines to check if any maintenance is required. Forest corridor clearing is normally performed every eight years. In addition, we make a clearance inspection every four years where we control the corridor and clear it of vegetation growing too close to the line. Before clearing we inform all affected landowners about the planned work.
We start by making a ground clearance where we remove smaller trees and shrubs. Then we mark and fell trees that are in danger of growing too close to the line in the next eight years or those outside the forest corridor.
Plan to maintain the power lines
|The power line and power line corridor are inspected with a low-flying helicopter. We take measures if necessary.
|Every four years
|We perform a clearance inspection. That includes controlling the line corridor and clearing the vegetation growing too close to the line.
|Every eight years
|We clear the forest corridor and fell "dangerous trees" in the side areas. The power line is inspected from the ground.
Effects on the local environment
Maintaining the grid naturally affects the local environment. We always try to take this into account.
If our work, for example, means more sunlight by a watercourse, we are often able to leave a small zone of low vegetation to maintain shade. Trees are usually felled by forest machine but if the ground is sensitive a chainsaw is used instead. Alternatively, we wait until there is frost in the ground because then the ground will not be damaged in the same way by heavy machinery.
If there are natural or cultural sites along a line corridor and these may be affected by our maintenance work, we always work with the County Administrative Board or Board of Forestry to come up with good solutions.
The clearing of line corridors also has a positive impact on flora and fauna. Corridors have proved to provide a pleasant environment for some plant and animal species.
Local knowledge is valuable
We are looking to have contact with you as a landowner to discuss which roads we can use and how we can carry out the clearing in the best way. We want to know if there are areas where we need to take particular account. The name and phone number of our local contact is sent out to affected landowners when we announce planned measures.
What compensation does the landowner receive?
Trees that grow along the edge and outside the part of the line corridor that Svenska kraftnät has redeemed belong to the landowner. When we have checked which of these trees need to be felled, we send a contract proposal to the landowner. The contract proposal regulates the compensation paid for the timber. The landowner can choose to either take care of the timber him- or herself, or to let Svenska kraftnät take care of it. The landowner receives compensation regardless of who takes care of the timber.
Safety around power lines
There are several safety rules that must be followed in and around the power line corridors. Their purpose is to prevent damage. For example it is not allowed to use the corridors as storage area for felling or to park vehicles. Read more about electrical safety.