Product Description

In this page figure brief explanations of the different ancillary services products and their role in maintaining the system’s balance and efficiency.

For more information you can also consult the different product sheets or contact Elia at


Primary frequency control (0-30 sec) – Frequency Containment Reserve (FCR, ex-R1)

The objective of primary frequency control is to maintain the balance between generation and consumption within the high-voltage European interconnected system. A deviation of this balance will lead to a deviation in the frequency which will automatically trigger the contracted primary reserves to be activated. The volume of the primary reserve is set by the European Network of Transmission System Operators for Electricity (ENTSO-E).

The global reaction of primary reserves set forth by the ENTSO-E regulations must be a symmetrical and linear activation with a total activation at a frequency deviation of +-200mHz.

However in order to allow different types of flexibility (generation, load) to participate in primary reserves, Elia sources different service types who react at different frequency deviations. Together these service types will deliver the product required by ENTSO-E:

  • FCR symmetrical 200mHz: this product is activated between -200mHz and + 200mHz, whereas the total contracted volume must be activated at the most extreme bands of the frequency interval indicated here above.
  • FCR symmetrical 100mHz: this product is activated between -100mHz and +100mHz, whereas the total contracted volume must be activated at the most extreme bands of the frequency interval indicated above. This maximum contracted volume must however also remain activated for frequency deviations between [-200mHz,-100mHz] and [100mHz, 200mHz].
  • FCR upwards: this product is activated between [-200mHz, -100mHz], whereas the total contracted volume must be activated at -200mHz.
  • FCR downwards: this product is activated between [100mHz, 200mHz], whereas the total contracted volume must be activated at 200mHz.

All of these service types can be offered from CIPU & non-CIPU generation or load resources.
All FCR symmetric & asymmetric products are offered in a weekly tendering. Elia also procures part of its FCR volume (only the 200mHz symmetric service type) from a regional platform common with TSO’s from Germany, Austria, the Netherlands, Switzerland, France and Denmark.

Volumes for a certain delivery period are procured in two stages: first, an auction held in the local platform held in W-2 before start of the delivery period and afterwards in an auction of the regional platform in W-1 before delivery period. The volume procured on the regional auction is variable and decided each week as a result of the financial optimization of the local auction. For more information about short-term purchases and the auction calendar, please refer to the page STAR (Short Term Auctioning of Reserves).

In the local platform auction the FCR symmetric products can be offered in a combined way with the asymmetric R2-products. Elia remunerates the supplier for making the capacity 100% of the time available.


Secondary control (30 sec - 15 min) – R2

Elia also has a symmetric secondary reserve it can activate to balance its own grid, which is procured from Belgian generators located on the Elia-grid. These reserves are activated based on a setpoint that is sent continuously to the supplier. Although Elia is looking for the same amount of upwards as downwards secondary reserves, Elia foresees the possibility to offer separately upwards and downwards volumes. All R2-symmetric & asymmetric products can be offered via a weekly tendering as of August 2016. R2-asymmetric-products can be offered in a combined way with the symmetric R1-product.    


Tertiary control with reserved volumes (15 min) – (R3 Std/R3 Flex)

Elia also procures tertiary reserves from Belgian generators as well as load connected to the TSO and DSO grid.

Elia procures the R3 Standard and R3 Flex who are offered by CIPU and non-CIPU demand or generation technical units alike. Both Elia as DSO-connected non-CIPU generation or load are able to participate in the month-ahead tendering.

Tertiary control reserves (as materialized in different products) are activated manually upon reception of a signal by Elia. Activations of the tertiary reserve vary through the year, depending on incidents and congestion on the grid.

These services are activated within 15 minutes from reception of the signal by Elia.

For more information on the technical characteristics of the two products please consult the concerned product sheet available hereby under.


Tertiary control with non-reserved volumes – (R3 Non-Reserved)

As of July 2017, non-CIPU generation and load can offer non-reserved power volumes to Elia. The offered volumes are submitted through the BMAP (Balancing Market Platform) web platform.

Suppliers are activated by Elia in case of need and are only remunerated for the provided energy (and not for their availability).

When activated by Elia, the Supplier should activate the offered volume as soon as possible within a margin of 15 minutes.


Voltage control (MVAR)

Under the Federal Grid Code, generators with units exceeding 25 MVA have to contribute to the generation and absorption of reactive power to maintain the voltage level within the required range (automatic control).

To increase flexibility, Elia contracts from generators a positive and negative control band for each unit (centralized control). If the system has a high load, Elia asks for extra MVArs to be generated, whereas when the load is low, it resorts to the absorption of MVArs.

Since reactive power cannot be transmitted over long distances, Elia bases its choice of the units participating in this service on their location.

The contract for this service gives two price rates: a fixed rate to remunerate one-time expenses (IT implementation, technical adaptations to the unit to expand the technical band) and an activation price remunerating the produced and absorbed reactive energy providing a minimum level of MW injection by the concerned unit. Penalties are applied in case the automatic or centralized control are not well executed.

Elia contracts some 6300 MVAr of generation capacity and 3200 MVAr of absorption capacity. The contracts have a period of one year.

For more information on the technical characteristics of this product please consult the concerned product sheet available hereby under.


Black Start

In line with its obligations, Elia makes sure it can restore its grid in the event of a blackout. It does this by using generation units that can start up without an external electricity supply.

Black-start contracts are signed for a number of years with Belgian generators that have such facilities. The supplier receives a fixed payment for supplying this service, regardless of whether it is activated or not. The participating units have to meet certain technical criteria regarding e.g. power (at least 100 to 200 MW depending on the case) and grid restoration time. The units are selected on the basis of cost (total cost and relative cost vis-à-vis power) and their location.

They must also be able to operate smoothly at any time, and therefore regular tests are carried out. They are paid for and penalties are imposed if they are not passed.

For more information on the technical characteristics of this product please consult the concerned product sheet available hereby under.


Purchasing procedure

Ancillary services are purchased using the European public procurement procedures. Elia publishes all the documents required by the legislation on the relevant European Union site.

At the end of every year, Elia publishes a Periodic Indicative Notice (PIN) which sets out the services that will be bought the following year.

Before start of procurement of each product a Contract Notice or Qualification System Notice is published inviting interested suppliers to apply. The procedure to follow and the list of documents that must be provided are detailed in the publication.

Candidates can be excluded on the grounds of specific exclusion criteria, such as for being in a state of bankruptcy, judiciary convictions etc. Elia will also ask for a financial screening of the candidate (generally a financial report performed by an independent evaluation house taking into account balance sheets, liquidity ratios, solvency etc.).

As a regulated company, Elia has to submit the prices at which it buys ancillary services to the Belgian Minister for Energy, Environment and Sustainable Development for approval. The Commission for Electricity and Gas Regulation (CREG) approves the volumes.