Ancillary services

Ancillary services in the electricity supply sector are defined as services provided by grid operators to customers in addition to the transmission and distribution of electrical energy. To ensure the secure operation of the system. Swissgrid organises the following ancillary services as part of its legal obligations:

  • Frequency control (primary, secondary and tertiary control)
  • Voltage support
  • Compensation of active power losses
  • Black start and island operation capability
  • System coordination
  • Operational measurement

To meet its ancillary services obligations, Swissgrid concludes a framework agreement with service providers following a technical and operational appraisal of providers and their power plants (prequalification). This is the basis for the participation of providers in ancillary service tenders.

Black start and island operation capability

Swissgrid has the task to ensure the availability of ancillary services including black start and island operation capability (refer to Art. 4 Para. 1 i. V. m. Art. 20 Para. 2 lit. b of the Electricity Supply Act). Swissgrid ensures that for the reestablishment of supply after a major incident an adequate number of powerstations, qualified for black start and island operation consolidated to a buildup-cell, are ready for operation.

A buildup-cell is defined as a small subnet, limited in area and electrical network, which consists of one powerstation equipped with black start facilities and one or more powerstations with islanding functionality being able to keep frequency, voltage and power stable in this buildup-cell, with an adequate load at its disposal. The buildup-cell needs to have a direct connection to the 220-kV-level.

The new contract agreement regulates the rights and obligations between Swissgrid and the buildup-cell-Manager (BCM) in order to ensure the capability of black start and island operation on the behalf of Swissgrid. The BCM manages independently, together with his relevant control centres, to establish the buildup-cell in a defined region for rebuilding the network until he is ready for receiving a voltage set value and the handover of responsibility to Swissgrid.

The constitution of the contract is based on the concept for rebuilding the network, dated the 24th of Sept.2012, which has been approved by the company management of Swissgrid after the consultation of the working group «Netzwiederaufbau» with representatives from end customer connected to transmission grid, distribution network and operators of powerstations.

The ancillary service «black start and island operation» for the provision starting from 1st of Jan. 2017 will be procured in an auction.

The actual contract version including annexes and the concept for rebuilding the network can be found in the protected area of the Swissgrid customer portal.



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