Distribution System Operators Observatory

From European Electricity Distribution Systems to Representative Distribution Networks

This report presents the latest JRC data brokering and modelling efforts in the power system area, with particular focus on the European distribution system operators and their distribution networks.

To the best of our knowledge, this is the most comprehensive data collection exercise on European distribution systems published so far. 79 out of the 190 larger Distribution System Operators (i.e. those serving over 100,000 customers and hence subjected to the EU unbundling provisions) are covered by our research. The respondents manage more than 70% of the electricity supplied by all Distribution System Operators serving over 100,000 customers.

Based upon this inventory and on the Reference Network Model tool, representative distribution networks were developed to analyse the impact of Renewable Energy Sources (RES) penetration and network automation on the distribution systems. By producing a realistic distribution network, the representative distribution networks offer the possibility to simulate the impact of different scenarios on large-size grids without having access to the actual network data.

Building upon the collected data:

  • 36 distribution system indicators were built, split in three categories: network structure, network design and distributed generation;
  • A total of 13 different representative distribution networks with different voltage levels were built: 3 large scale geo-referenced networks (urban, semi-urban and rural) and 10 feeder-type networks with common topologies, available for download by clicking the link below: "please click here".

Over the last years, the Joint Research Centre of the European Commission has expanded its role as an independent observer of the energy system. A big effort has been devoted to collect, process and analyse data on the power sector (from smart grid project costs and benefits to consumer engagement strategies, from power system techno-economic features to integrated regional systems/markets).

Successful steps have been made with respect to inventorying most of the Smart Grid Projects in Europe and a similar exercise is in progress towards mapping the Smart Grid Laboratories in Europe and US.

Up to now, little publicly available information was available on the European distribution system operators (DSOs) and the networks they operate. This lack of knowledge is partially attributable to constraints in sharing data that DSOs consider as assets of commercial value, but it is also due to the vast number and heterogeneity of the distribution systems in Europe. The situation varies radically from country to country, due to historical as well as geographical, legal, political and economic reasons. In some Member States there is only one DSO, while in others there are tens or hundreds of them operating their networks on a regional or even municipal basis. Differences concern also other aspects, e.g. the scope of the DSO activities, the level of unbundling, the operated voltage levels and other key technical information on the networks.

This activity aims at providing stakeholders with tools and analyses to better understand the rapidly changing power system scene, enabling early identification of distribution system developments and trends and supporting evidence-based policy making. In particular, this work aims at helping the power system stakeholders better understanding status and specificities of the great variety of distribution networks and the challenges that the energy system transition is posing to European distribution system operators.

The starting point of the DSO Observatory project was the collection of technical and topological data from the DSOs. An online survey was launched in January 2015 with the aim of collecting several clusters of data, relating to types of ownership and unbundling, network structures and designs, amounts and types of connected distributed generation, and reliability of supply indicators. 79 out of the 190 larger DSOs responded to the survey. 

 Given the vast number of DSOs in Europe, the data collection exercise was limited to the bigger ones, i.e. the 190 DSOs that have to comply with the unbundling requirements set out in the EU Electricity Directive (i.e. the DSOs serving more than 100,000 customers).

Overall, the 79 DSOs distribute more than 2,000 TWh of electricity to over 200 million customers per year, covering a total area of more than 3 million square km. The representativeness of the sample is quite high: the respondents manage more than 70% of the electricity supplied by all Distribution System Operators serving over 100,000 customers.T

he collected data were used to build 36 indicators, divided in three categories, i.e. network structure, network design and distributed generation. These indicators allow for comparison of the parameters and criteria used by DSOs when designing and sizing their network installations. They help to shed some light on the different characteristics of some of the major European distribution networks and to support research activities by reducing the amount of resources that are typically devoted to compiling input data and building case studies.

The project also aimed at providing a tool to enable more sophisticated technical and economic assessments of several policy options and technological solutions. 

For this purpose, 10 of the 36 indicators were chosen to create representative distribution networks by using the Reference Network Models, i.e. large-scale network distribution planning tools that allow designing realistic distribution networks. The Reference Network Models allow analysts and researchers to design networks supplying the expected demand while minimising the total investment (and the associated operational costs) and meeting the defined reliability of supply criteria.

Two large-scale representative networks, a rural and a urban one, were selected to carry out the simulations and analyses. The impact of increasing levels of RES penetration, in particular solar photovoltaic (PV) and wind, on the techno-economic performances of the grid was assessed.

The JRC will continue to carry out its scientific and policy support activities in the power system fields to better understand and address the challenges DSOs face in the transition to a smarter energy system. In order to increase the knowledge base of the evolving electricity distribution sector, the results of these activities will be made publicly available. This report can be then seen as the first step of a periodic mapping and modelling exercise, which the JRC aims to continue with the support of the relevant electricity system stakeholders, in order to help understanding the merits, challenges and options of the electricity system transition.

  • Do you want to join our DSO mapping exercise?
  • Do you wish to work with us at deploying/developing representative network models?
  • Do you want more information on our next release of the DSO observatory?
  • Do you have any suggestion, question and/or other requests?

Click the link below or drop an email to JRC-IET-DSOPROJECT@ec.europa.eu and do not miss to visit this webpage in the near future.