Analyse der notwendigen Niederspannungsnetzentwicklung bei Ausschöpfung der Photovoltaik-Dachflächenpotenziale

Translated title of the contribution: Analysis of the necessary low-voltage grid development when utilising the potential of photovoltaic roof areas

Anna Murbacher

Research output: ThesisMaster's Thesis


The increase in renewable energy producers presents grid operators in Austria with the challenge of integrating the additional capacity into the existing infrastructure. Photovoltaics (PV) play a key role here, due to the current large number of possible subsidies and the associated option of counteracting the rise in electricity and gas prices. The integration of PV systems into the existing distribution grid leads to considerable effort in the assessment of suitable connection points. This master's thesis analyses the potential of photovoltaics on roofs in the province of Salzburg, especially the supply area of the distribution system operator Salzburg Netz GmbH. Based on the global radiation per roof surface, the potential output for feeding into the low-voltage grid is calculated. This considerable potential is taken to identify the needs for action at the low-voltage grid level to secure the supply for the future. The central research questions are the effects of the roof area potential on the low-voltage grid and the necessary changes to integrate the future feed-in power. To answer these questions, the current utilisation is determined by analysing measurement data for the current low-voltage grid in MATLAB®. This provides insights into the initial state of the low-voltage grid. By determining the PV potential for roof areas using values from the solar cadastre for Salzburg and researched literature, a prediction can be made for future feed-in loads. Repeating the capacity calculation and identifying bottlenecks makes it possible to determine the potential for expanding the low-voltage grid in Salzburg Netz GmbH's supply area through strategic grid planning and the creation of exemplary local grids. The local grids are modelled using load flow calculations in NEPLAN® and the economic costs of various expansion strategies are evaluated. The analysis of the PV roof area potential shows an eightfold increase in the current output in the low-voltage grid of Salzburg Netz GmbH. This leads to increased utilisation of the transformers that ensure energy transport between the medium and low-voltage grid. At least one additional transformer must be built at almost one fifth of the transformer stations in the low-voltage grid to be able to transmit the power. The modelling of local grids where at least one transformer needs to be replaced to transfer the power shows the various expansion options and the difficulty of finding locations for additional stations. In the economic analysis of these local grids, the use of Voltage Regulated Distribution Transformers is particularly favourable. The same applies to the combined use of Voltage Regulated Distribution Transformers and series regulators, which also proves to be the most economical solution in a local network. In contrast, the laying of parallel cables leads to high costs with such a large increase in power.
Translated title of the contributionAnalysis of the necessary low-voltage grid development when utilising the potential of photovoltaic roof areas
Original languageGerman
Awarding Institution
  • Montanuniversität
  • Kienberger, Thomas, Supervisor (internal)
  • Vopava-Wrienz, Julia, Co-Supervisor (internal)
Award date28 Jun 2024
Publication statusPublished - 2024

Bibliographical note

no embargo


  • Potovoltaics
  • Distribution Grid
  • Grid
  • Expansion

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