Differences between overhead and underground power lines in the practical example of the DV 20 kV Črešnjevci

The aim of our thesis was to present the differences between overhead and underground power lines on the practical example of the DV 20 kV Črešnjevci transmission line, which, due to the requirement to increase operational reliability and robustness, was implemented as the KB 20 kV Črešnjevci cable line in 2022.

We wanted to find out whether the construction of an overhead power line represents a greater interference with nature than the construction of an underground power line, whether the construction of overhead power lines is cheaper than the construction of underground power lines, whether the construction of an overhead power line is more dangerous than the construction of an underground power line during the work, and whether the construction of an underground power line represents for the population and economy a higher level of safety than an overhead power line.

We verified the assumptions based on the review of legislative requirements for construction, comparison of construction costs from the project documentation for the implementation of construction, review of legislative requirements at work and statistical data on accidents at work and dangerous events in electricity distribution companies, and review of technical conditions for construction and statistical data on continuity power supply.

Procedurally, the new construction of a 20 kV transmission line does not differ significantly from the new construction of a 20 kV cable line. None of them is a facility with environmental impacts, for which an environmental impact assessment should be carried out before the start of the intervention in accordance with the regulations governing environmental protection.

If we do not take into account the lifetime, we should conclude that the construction of a 20 kV transmission line with concrete supports is a little cheaper than the construction of a 20 kV cable line, but taking into account the life span, we must conclude that the construction of a 20 kV transmission line with concrete supports is a little more expensive than the construction of a cable line 20 kV.

If the measures to ensure safety and health at work are observed and implemented, there should be no danger at work either during the construction of the 20 kV transmission line or during the construction of the 20 kV cable line.

From the point of view of safety, the regulations basically ensure the same level of safety for the population and the economy for both 20 kV transmission lines and 20 kV cable lines, and from the point of view of continuity of power supply, due to force majeure, external and internal causes, 20 kV cable lines provide a significantly higher level of safety than transmission lines 20 kV.