With the amendment of the Energy Industry Act (EnWG) of 20 December 2012, the legislator created the possibility to also contractually oblige interruptible load suppliers to take the necessary measures to maintain grid and system security. In this respect, §13(4a) and (4b) of the EnWG establish the legal groundwork for further specification of requirements, compensation and cost regulations in connection with the interruptible loads. These are specified in further detail in the Ordinance on Interruptible Load Agreements (AbLaV), which also lists the criteria for their technically and economically viable application.
For the purpose of the Ordinance, interruptible loads are defined as large consumption units which are connected to the (extra) high voltage grid, nearly continuously consume a large volume of electricity and which can, upon request, reduce their demand on short notice and for a fixed minimum duration thanks to the nature of their production process.
Pursuant to the AbLaV, the German transmission system operators will monthly call for a total breaking capacity of 3,000 megawatts. Each bidder with an interruptible load that meets the technical requirements stipulated in §§5 to 7 (incl.) of the AbLaV is entitled to participate in the tendering procedure. Proof that these requirements are indeed fulfilled, shall be given in a prequalification procedure.
The Ordinance on Interruptible Load Agreements can be downloaded here (German).
Prequalification
In accordance with the underlying AbLaV (German), the transmission system operator responsible for the connection enters into nationally uniform framework agreements with the interruptible load suppliers within its control area. The suppliers have to prove that the consumption units meet the transmission system operator's prequalification requirements as per the AbLaV in a nationally uniform prequalification procedure.
You can find all documents pertaining to the prequalification here (German).