Market for control reserve in Germany

The German transmission system operators (TSOs) have to maintain the balance between electricity generation and consumption within their control areas at all times. For the performance of this task, the TSOs need different types of control reserve (primary control reserve, secondary control reserve as well as minute reserve, which is also called tertiary control reserve). These types differ according to the principle of activation and their activation speed. Close co-operation between the TSOs contributes to keeping the total requirements for control reserve as low as possible.

Since 2001, the German TSOs have been procuring their required primary control reserve, secondary control reserve as well as minute reserve on an open, transparent and non-discriminatory market for control reserve according to the guidelines of the Federal Cartel Office (Bundeskartellamt - BKartA).

The procurement is carried out as a tender auction on the German Control Reserve Market with participation of numerous bidders (both plant operators and electricity customers).

By pooling technical units (generation facilities and controllable consumer loads) in order to reach the minimum lot size (see description of the different control reserve types), it is also possible for small bidders to take part in the tender.

Until 30th November 2007, the procurement of primary and secondary control reserve was carried out independently by each TSO every six months. Prior to the start of the joint procurement, each TSO already individually procured its minute reserve via daily tenders. In order to process these daily tenders, the German TSOs had developed IT-based procurement platforms along with suitably defined, market-based control reserve products able to support the stable operation of the grid.

With the entry into force of the Energy Industry Act (abbreviated as "EnWG" in German) on 13th July 2005 as well as the associated Electricity Network Access Ordinance ("StromNZV") and Electricity Grid Access Charges Ordinance ("StromNEV") on 29th July 2005, the legal framework for procurement and use of control reserve changed significantly.

Since 1st December 2006, the minute reserve required by the four TSOs has been procured via a joint tender. For this purpose, the TSOs' common Internet platform www.regelleistung.net is available. A joint tender for the procurement of primary and secondary control reserve was introduced one year later on 1st December 2007 and is also processed via www.regelleistung.net.

A technically needed amount of control reserve (core portion) may need to be provided from within the TSO's control area (i.e. by technical units connected to the grid within the TSO's control area) as required by Section 6 (2) of the Electricity Network Access Ordinance (StromNZV), the objective being to ensure security of supply in each control area, even in case of disturbances in the grid. As such, it is guaranteed that this amount of control reserve is always provided by the own control area.

the scope of a systematic further development of joint procurement, the German TSOs cooperate at operational level through the coordinated use of control reserve in the grid control cooperation (GCC):

  • In December 2008, the German TSOs EnBW Transportnetze AG (TNG), E.ON Netz GmbH (today: TenneT TSO GmbH) and Vattenfall Europe Transmission GmbH (today: 50Hertz Transmission GmbH)) have put into operation Module 1 of the GCC. This serves to avoid a reverse retrieval of control reserve (secondary control reserve and minute reserve).
  • In May 2009, Module 2 of the GCC followed, allowing the TSO a common dimensioning of the control reserve, which is equivalent to a single control area, since the control reserve is now being held jointly (secondary control reserve and minute reserve).
  • The establishment of a single control power market for secondary control reserve Module 3 followed in July 2009 and was completed in September 2009 by the cost-effective secondary control reserve retrieval across control areas (Module 4).
  • In May 2010, the fourth German TSO, Amprion GmbH, joined the grid control cooperation.
  • Since July 2010, the four German TSOs also retrieve the minute reserve in all four areas at optimum price. Therefore, all synergies related to the grid regulation in Germany can be exploited.
  • As the grid control cooperation is open to collaboration with other control areas outside Germany, there is still a potential for further cost saving.

Market description

The following study from Consentec describe the control power market and the control power concepts. In the description of the market following aspects are covered:

  • Legal and regulatory framework
  • Network access model
  • Realisation of power-frequency control
  • Pre-qualification of suppliers and provision and use of control reserve
  • Determination and settlement of balancing energy

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Studies

This page lists final reports of studies in the field of control reserve which have been conducted or supported by the German Transmission System Operators.