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Virtual power plants

The purpose of virtual power plants is to link the energy production of smaller plants, so that grid operators can treat them as one large power plant. They usually consist of a mix of photovoltaic systems and wind turbines supplemented by biomass and hydroelectric power plants. However, geothermal plants and CHPs can also contribute their output and partake in virtual power plants.

The control centre communicates with the individual plants and determines the amount of energy required by the grid. In addition, it checks to see how much power can be supplied by volatile producers at the present time. For predictions, it relies on high-resolution weather data and combines it with local data of the producers. With this information and with price forecasts for the electricity markets, a virtual power plant can then feed in electricity.

One disadvantage is the communication overhead. It requires a lot of computing power and incurs additional costs. Nevertheless, virtual power plants could maintain a secure energy supply in the future.

Research for modern grids

A successful energy transition is only possible with effective grid expansion. To this end, the German Federal Ministries for Economic Affairs and Energy as well as Education and Research granted the ‘Future-proof Power Grids’ research initiative 150 million euros. The supported projects range from basic research to specific applications and products – in distribution grids, transmission systems and offshore grid connection. The projects of the initiative include the following:

Connecting offshore networks to the grid – A major challenge of the future energy supply is, amongst others, the grid connection of offshore wind farms. While the first farms are already feeding into the grid, further research can improve the connection and allow for a network of wind farms. In the NSON project, scientists are analysing different network connectivity options of a prospective offshore power grid, including the impact on the German and European interconnected grid.

Transporting more power with a line system – The project participants of the research project DCCTL are reviewing whether or not existing power lines can be used to transport more power. Existing three-phase systems would carry up to 3,000 MVA instead of 2,000 MVA. In hybrid DC overhead line systems, pylons would carry both DC and AC. The direct-current systems would carry up to five gigawatts. Another research goal is laying underground cables – because Germany is densely populated and overhead lines cannot be installed everywhere.

Preparing Europe’s electricity grid for renewable energy – Back when today’s grid was being built, distributed generation and renewable energy sources were not an issue. This is why the grid is optimised for different conditions. As part of the GENESYS2 project, researchers are investigating what is necessary for an efficient grid expansion, and how it might be implemented. The boundary conditions are determined by the existing grid. Existing lines, substations and power supply voltages cannot be changed easily. The results will highlight different developmental paths and make them comparable. Scientists will be able to recommend economically viable scenarios in addition to technically viable ones.

Further research projects and information on the progress made so far is available at http://forschung-stromnetze.info/en/.

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Addresses

Project management
Fraunhofer IEE

Scientific monitoring
CUBE Engineering GmbH

Industrial partner
ENERCON GmbH

Industrial partner
SMA Solar Technology AG

Industrial partner
Siemens AG

Industrial partner
SolarWorld Innovations GmbH

Industrial partner
ÖKOBIT GmbH

Weather data
DWD

Links

Project homepage
with further information

Zukunftsfähige Stromnetze
Web portal for the research initiative on power grids with the latest research and development news