Grid restoration with future power plant structures

Project state

In the project NETZ:KRAFT, researchers are developing new grid restoration concepts for future power plant structures. The aim is to integrate renewable energies when restoring supply after a power outage. They are pursuing two main approaches.

Refining existing concepts

For the energy transition to work, renewable energy generation systems have to provide ancillary services. This includes grid restoration, during which power supply is restored and stabilised after a major fault or power outage. This is to be made possible even if a high share of decentralised power plants is contributing to grid supply. This is why the researchers are preparing the grid restoration concepts for a further rise in the share of renewable energy generation systems. In the short term, the handling of renewable energy generation systems in the sub-networks of a network region during restoration must be considered, and in the medium term the possibilities of an active contribution to the restoration by large renewable energy systems (wind or solar farms), and in the long term the behaviour of feed-in from HVDC overlay networks. These considerations should take into account the requirements of the necessary ICT infrastructure and its availability, both within one voltage level, as well as cross-level.

Active use of decentralised systems in supply islands

In the long term, the increasing shift towards nationwide electricity generation on all grid levels allows for the development of supply islands of different sizes, from the low-voltage grid to the high-voltage grid. In case of longer-term faults in the upstream grid areas, these supply islands can help shorten downtimes. Technologies and procedures for (grid) independent operation, black starts, operation and synchronisation of supply islands with each other and with upstream networks are being developed in the NETZ:KRAFT project.

Overall, the researchers are investigating the coordination of the two strings as to their interdependence and the necessary technical and organisational requirements. The aim is to actively involve renewables in grid restoration with, or optionally also without, external voltage control.

Concepts, methods and technologies are being developed, with which renewable energy generation systems and smart grid components can become active function owners during grid restoration. Scenarios of supply situations are specified in case studies using the necessary technologies and processes. Technological developments as required by the case studies will be implemented in six demonstration projects.

The 20 partners of the NETZ:KRAFT consortium in the overview

Amprion GmbH
Avacon AG
DERlab e.V.
Dutrain GmbH
EnergieNetz Mitte GmbH
Energiequelle GmbH
Fraunhofer IWES | Institutsteil Energiesystemtechnik
Friedrich-Alexander-Universität Erlangen-Nürnberg
50Hertz Transmission GmbH
GridLab GmbH
HanseWerk AG
Mitteldeutsche Netzgesellschaft Strom mbH
SMA Solar Technology AG
TenneT TSO GmbH
TransnetBW GmbH
Universität Kassel e2n

Project duration

01/2015 – 06/2018


Wolfram Heckmann
Fraunhofer IWES
Königstor 59
34119 Kassel
+49 561 7294-126
+49 561 7294-200


Project presentation on the homepage of Fraunhofer IWES

Project presentation downloadable as a PDF file (23 pages, 2 MB)


Project presentation as a PDF download, Conference on Future-proof Power Grids, 22-23 September 2016, Berlin (17 pages) (German)

Publication of grid restoration concepts: Possible interaction between wind turbines and thermal power plants, VGB Power Tech KELI 2016, 11-12 May 2016, Cologne (German)

Basic information

The energy generated in a grid must always be equal to the energy consumed. The ancillary services are tasked with ensuring this.


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