Transmission system operators 50Hertz and Energinet have performed a live simulation of a power grid restart using offshore wind energy.
The simulation of a power outage in Continental Europe was performed with coal-fired power plant Rostock and voltage supplied from Denmark.
This was the first time a land and sea cable connection between two countries as well as offshore wind power were used in real conditions to restart a power plant, according to 50Hertz.
A recently inaugurated interconnector between Germany and Denmark, known as the Combined Grid Solution (CGS), was used as a “starting aid” to fire up the power plants turbines.
The CGS is a hybrid system with a capacity of 400MW that transmits electricity between both countries.
EnBW wind farms Baltic 1 (pictured) and Baltic 2 are also integrated into the CGS and supply electricity to the 50Hertz transmission system.
In 2021 Vattenfall’s Kriegers Flak wind farm will be connected to the Danish transmission system.
To restart the power plant, Rostock was initially first completely separated from the German power grid.
Subsequently, Danish system operator Energinet provided the required 380-kV voltage via the CGS and the newly constructed converter systems in the substation in Bentwisch near Rostock.
50Hertz chief markets and system operations officer Dirk Biermann said: “This successful start-up attempt illustrates the importance of cooperation at European level in the age of renewables.
“In close cooperation with our Danish colleagues, the system management departments of Energinet and 50Hertz have demonstrated their capacity for innovation as well as their level of professionalism.”
Start-up attempts are part of the grid restoration plans of transmission system operators.
Their capability has to be tested regularly in their corresponding grid areas to guarantee the swiftest possible restoration of the electricity grid after a power outage.
Traditionally, storage or gas-fired power stations are used, because they do not need external power sources to start up.
This for instance includes pumped storage stations with hydro power. Other thermal power stations are usually not ‘black start capable’ without a powerful external power source, as they already need a lot of energy to start up.