380-kV Salzburg Line
Construction of the new line will not only secure the supply of electricity in Salzburg and the rest of Austria, but is also crucial for achieving Austria’s climate targets.
With the goal of improving security of supply to the city of Salzburg, the first 46-km long section of the Salzburg line from the St. Peter node to the newly built Salzburg substation near Elixhausen was completed ahead of schedule and commissioned in January 2011. The project is now focusing on finalising the second section of the Salzburg line so as to close the western gap in the ring. Completing the ring in combination with finishing construction of the Wagenham substation will also improve security of supply in the economic region of Braunau.
380-kV security ringAustria’s high-performance ultra-high voltage grid is characterized by its ring structure, which allows customers to be supplied with power from both directions. The 380-kV ring is the backbone of Austria’s electricity supply, and the new Salzburg line will close the gap in the ring in western Austria. The existing 220-kV line will be replaced by a new 380-kV line from the node at St. Peter am Hart (Upper Austria) to the Tauern bei Kaprun node (Salzburg).
Federal Administrative Court upholds EIA approval notice
On 5 March 2019, the Federal Administrative Court in Vienna upheld the environmental impact assessment (EIA) approval notice for one of Austria’s most important infrastructure projects – the Salzburg line.
Following a hearing held in July 2017 and a detailed review of all arguments put forward, the Federal Administrative Court issued a decision upholding the EIA notice from the Salzburg state government approving the plan submitted for the route of the 380-kV overhead line.
Facts & Figures
Major improvement in security of supply for Salzburg and Austria as a whole
APG’s existing 220-kV electricity line was built in 1960. The line runs from the Salzburg (Elixhausen) substation across the Hagen mountain range to the Tauern (Kaprun) substation. After so many decades in operation, the line is urgently in need of modernisation: the Austrian state of Salzburg obtains more than 50% of the electricity it needs from the APG transmission grid on average. Construction of the new 380-kV Salzburg line will ensure a continued stable supply of electricity for the region. It will also improve Austria’s overall security of supply since the new line will enable the projected increasing demand for electricity to be met in the coming decades.
Essential project for reaching Austrian climate targets
The Salzburg line is one of Austria’s most important energy transition projects. In recent years, the volumes of electricity produced from clean energy sources, especially wind power, have been rising steadily. The Salzburg line is a key factor in supporting the efficient use of clean energy. It will connect the wind power hot spots in eastern Austria to storage power plants in the Alps, transporting surplus wind power that isn’t needed at the point of generation to these “green batteries” used to store the electricity. The electricity can then be harvested from the storage power plants as needed.
Fewer overhead transmission lines for Salzburg
The high-voltage Salzburg line also represents an important step in implementing Salzburg Netz GmbH’s comprehensive grid concept, which involves running certain line sections owned by Salzburg Netz GmbH along the Salzburg line route and sharing the same transmission towers (double circuit lines). The project also includes dismantling APG’s old 220-kV lines. Upon completion of the project, Salzburg will have 65 fewer kilometres of lines and 229 fewer masts in total than it does today.
Investment volume of around EUR 800 million, 7,000 new jobs
Construction of the Salzburg line will consume a planned investment volume of around EUR 800 million. This will create approximately 7,000 jobs over the course of the project, around 2,250 of them in Salzburg. The Salzburg line has been planned and prepared with the greatest care and in close cooperation with local stakeholders. The documentation submitted for the project totals 11,000 pages, including 1,200 blueprint designs, and expert opinions have been commissioned in 23 fields along with comparative opinions from the authorities.
|Total investment volume||approx. EUR 800 million|
|Total distance covered||128 km|
|of which 380-kV lines||114 km|
|of which 220-kV lines||14 km|
|110-kV cabling||6.7 km|
|New electricity plyons||449|
|of which 380 kV||404|
|of which 220 kV||45|
|To be dismantled|
|220/110-kV lines||193 km|
|Double circuit lines|
|110-kV lines||38 km|
|of which newly built||2|
|of which converted/adapted||4|
The 380-kV Salzburg line is being built as an overhead line, since this form of technical implementation corresponds to the current international state of the art as well as operational practice. Given that the Salzburg line is of supra-regional significance, it must meet “N-1” redundancy criteria. N-1 redundancy refers to an international safety standard that must be adhered to in planning and operating power lines and transmission grids. This is a necessary precaution to ensure that the supply of electricity is not disrupted in the event of a malfunction in the system, for example if another line or a transformer fails. To meet the N-1 criteria, the Salzburg line is being built as a dual-system line. Each of the Salzburg line’s two systems consists of three phases. The structural arrangement of the individual phases depends on the plyon design used. Either one phase is located on each cross arm of the plyon (tons plyon), or two phases are located on the lower cross arm of the plyon (danube plyon). Each of the phases consists of a bundle of conductor cables (bundle conductor). In high-voltage and ultra-high voltage transmission lines, the conductors are usually bundled into groups of three of four. For the Salzburg line, a three-bundle configuration has been selected – this means that each bundle consists of three separate conductors. Use of the three-bundle configuration also leads to a significant reduction in corona noise.
In addition to the conductors, an earth wire is attached to the top of the tower to protect against direct lightning strikes.
Two different plyon types are being used in constructing the Salzburg line: “danube” plyons with two cross-arm levels and “tons” plyons with three cross-arm levels.
The decision about which of the two plyon types will be used at a specific location depends mainly on whether the local topography is flat or hilly. Since danube plyons only have two cross-arm levels, they appear much more compact and are also lower than tons plyons. This is of significance when the terrain is mostly flat and offers widespread views. Tons plyons look slimmer on the whole due to their shorter cross arms, but they are higher than danube plyons. However, the shorter cross arms have the advantage that less surface area is needed, which is especially advantageous in mountainous regions where space is often limited. Therefore, the natural terrain determines whether the danube plyon type or the tons plyon type can be better integrated into the landscape. A great deal can be done to minimise the visibility of the lines by making optimum use of the interplay between terrain and plyon type and the ability to “hide” the lines to a certain extent. The olive green colour of the plyons also helps to reduce their visibility.
However, it is not only the type of plyon selected that determines how high the Salzburg line plyons will be at the respective locations. Local conditions play a large role here too. The most important factors are:
- the distance to be covered between two plyons
- the topography between the two plyons to be connected (e.g. hilltops)
- any obstacles between the two plyons (other lines, rivers, roads, etc.)
- whether other lines are to be included (e.g. lines from Salzburg Netz GmbH)
As a rule, however, danube plyons are 48 metres high and tons plyons are 52 metres high. In addition to these two traditional plyon types, a new plyon type is being erected along one stretch of the Salzburg line – the “tubular” plyon.
Land is generally appropriated either when a transmission tower is to be erected on it or if it is to be transversed by a transmission line, in which case an easement must be granted. The compensation paid for appropriated land is regulated uniformly for all property owners in the framework agreement with the Chamber of Commerce of the State of Salzburg from October 2010. If the land appropriated involves forested area that has to be cleared in order to install the lines, the compensation to be paid is assessed by an expert on the basis of the framework agreement. The assessment is made in accordance with recognised methods for appraising the value of forested areas and takes the following into account, among other things:
- permanent loss of use
- loss of future revenue due to felling immature forests
- forced use at an economically inopportune time
- forest management hindrances
- decrease in land value and yields
- damage at forest edges (due to clearing that exposes previously protected trees to the elements)
Sometimes it is necessary to fell trees on the land appropriated for the project, at least during the construction period. After inspecting the existing stock of trees in accordance with the relevant specifications, the surface area in which trees are to be felled is calculated such that no trees can fall onto the line during operation.
Three main factors are significant here:
- the tree height
- the height of the lines and
- the slope of the land
In many cases, the lines cross the forest at such a height that it is not necessary to fell any trees for construction or operation of the line. APG pays compensation pursuant to the framework agreement in such cases.
Once the construction work is completed, the area along the transmission line route is reforested as provided for in the EIA approval notice. The property owners are able to choose whether they want to reforest their land themselves in return for the compensation stipulated in the framework agreement, or if the reforestation should be undertaken by a firm contracted by APG that will also take care of plant cultivation until care is no longer required. In any case, the building authority for forest ecology checks to ensure that the conditions listed in the approval notice have been complied with.
Wagramer Straße 19
Wagramer Straße 19
5600 Sankt Johann im Pongau
Power Line Route
Projects of Common Interest (PCI)
Implementing a modern infrastructure made up of reliable power grids is crucial to achieving an integrated European energy market that offers the best possible cost-benefit ratio to all consumers given the energy costs involved. In addition, the improvements being made to Europe’s existing network structure to meet the higher demands placed on power grids due to energy generation from renewable sources such as wind and solar represent the basis for reaching the 2020 climate targets. The European Commission therefore on 14 October 2013 adopted a Regulation containing a list of 248 key energy infrastructure projects, including some 140 projects in the area of electricity transmission and storage.
The projects will enable European power grids – and therefore the Austrian power grid as well – to handle increasing quantities of electricity from renewable energy sources, which will lead to a significant reduction in carbon emissions and achievement of the EU’s ambitious climate Targets.
The projects receive funding from the European Union from the budget for Trans-European Networks for Energy.