The transmission grid is designed to transport electricity from power plants at the high-voltage level (220 and 380 kilovolts). The high voltage allows a large amount of electricity to be transported across long distances with relatively low losses. In addition, the German transmission grid is connected to its European neighbors at border connection points so that power can be traded internationally.
To supply power directly to consumers, distribution grids work at a lower voltage. Here, a distinction is made between the high-voltage level (< 60 kV to <220 kV), the medium-voltage level (between 6 kV and 60 kV), and the low-voltage level (< 6 kV). The medium-voltage grid distributes electricity regionally, while the low-voltage grid provides power locally to consumers and small power purchasers.
Depending on the power generator's specific output, it can also be connected to these subordinate voltage levels. For instance, wind turbines are usually – around 96 percent of the time – connected to medium and high-voltage grids, i.e. to distribution grids. Only four percent of all of the wind turbines on the grid are connected to the transmission grid. Wind farms with a large capacity output, such as offshore wind farms, are, however, generally connected to the high-voltage level.