What this document is
Published in June 2008, this technical guideline from the German utility association BDEW sets out the requirements for connecting power-generating plants, including wind turbines, photovoltaic systems and combined heat and power units, to a network operator's medium-voltage grid. It replaced an earlier version issued under the name of BDEW's predecessor association, VDEW.
The document covers the full lifecycle of a connection: planning, construction, operation and later modification of a generating plant that will run in parallel with the medium-voltage network. A central requirement is that connected plants support the grid during disturbances rather than disconnecting immediately, including riding through voltage dips of up to 30 percent so that sudden faults do not trigger a cascade of generators dropping offline at once.
The guideline runs to 138 pages and also specifies power factor, harmonic distortion and protection-equipment requirements. It has since been amended several times, with a fourth amendment taking effect in January 2013, and remains a reference point for grid-connection rules in Germany even as newer, more detailed technical standards have been layered on top of it.
Where to find it
Available from VDE (hosting the BDEW guideline).