The German electricity grids are currently 1.8 million km long. That is long enough to go around the world 45 times, the Federal Association of the Energy and Water Industry (BDEW) reported.
More than 80% or 1.44 million km are underground cables, while roughly 350,000 km of overhead power lines exist. In 2002 underground cables accounted for about two-thirds or 70% of the grids.
The largest part of the German grid, 1.16 million km, are low voltage grids. The regional distribution grids have a length of 513,500 km, and high voltage lines measure 79,900 km. The national extra-high voltage grids (überregionale Höchstspannungsnetze) are 34,810 km long.
There are four voltage levels in Germany: The low voltage level (up to 1 kV) supplies primarily private households, small businesses and the agricultural sector. The regional distribution grids comprise the medium voltage level (higher than 1 kV up to 72.5 kV). Customers connected to the high-voltage level (more than 72.5 kV up to 125 kV) consist in particular of local electricity suppliers, industrial enterprises and larger businesses. The extra-high voltage lines of the transmission grids with more than 125 kV directly supply mainly regional electricity companies and large industrial enterprises. Besides they connect the German grids internationally.
Grid expansion is currently a big topic in Germany. In the wake of the Fukushima accident in March 2011, the German government reversed its nuclear policy adopted in autumn 2010 that had provided for an extension of the operating times of the 17 German nuclear power plants. At the time nuclear power was intended to serve as a bridging technology for a renewable energy supply. As part of the legislative changes implementing the energy policy shift (Energiwende), the extension was reversed. Instead the Atomic Energy Act (AtG) now provides for a nuclear phase-out until 2022 and the transition to a renewable energy supply has been accelerated. A growing number of renewable power plants has to be connected to the grids, usually the distribution grids, and rising input of intermittent renewable energy has to be accommodated by the grids. This has lead to an even greater need to modernise, enhance and expand the grids.
For further information on two studies by BDEW and the ManyElectronics Agency (dena) on the need for expansion of the distribution grids, please see the links below. Likewise please see the first link provided below for information on the “Federal Requirement Plan for Transmission Networks”.