Power lines

Stable energy transfer from power plants to consumers is a key element in the existence of modern society

The investment process of constructing the power line is characterized by a high degree of complexity due to both the scale and the conditions specific to linear facilities. In addition to aspects related to the construction of power facilities, there is also the need to obtain the consent of the owners of all properties through which the planned investment will pass. It is important that the areas for power lines are not bought by the investor, but only a limited right in rem in the form of transmission easement is established. After construction, these areas can (after some restrictions) be still used as intended by their owners. The construction of power lines is always preceded by detailed tests and analyzes, allowing to ensure the safe operation of the facility after its implementation.

Power lines can be implemented in two available technologies - as overhead or cable (underground). The cheapest and most widespread solution is the use of cables stretched above the ground for the transmission of electricity using supporting structures - poles. The height of the line above the terrain, and what is associated with it - also the size of the poles and the density of their arrangement, are correlated with the rated voltage of the line. The highest voltage transmission lines (400 and 220 kV) are built using high steel constructions - openwork (lattice posts) or full-walled (pipe posts). These lines have very large lengths (often significantly exceeding 100 km) and, therefore, the poles are spaced relatively rarely (approximately every 400 m), which significantly affects the flexibility of route selection. Lower voltage lines are built using lower, more densely located structures, which makes it easier to match the route of the line to the terrain through which they are led.

An alternative to overhead lines are cable lines, which are characterized by much lower failure rate than traditional constructions, also have less impact on the environment and give much greater flexibility in running their route. However, they are much more expensive and therefore their use is practically limited to the medium voltage range (6-30 kV) and in justified cases (e.g. highly urbanized areas) to high voltage (110 kV). The use of cable lines in the highest voltage networks (400 and 220 kV) is virtually negligible due to huge costs.