Elia Innovation

Bid Ladder

Elia maintains this grid balance by activating three types of control reserves:

  • Primary reserve for frequency control (R1 or FCR): participating actors react automatically and instantaneously within 0 to 30 seconds to frequency deviations.
  • Secondary reserve for automatic frequency restoration (R2 or aFRR): participating market actors react within 30 seconds to 15 minutes on the basis of an automatic signal sent by Elia.
  • Tertiary reserve for manual frequency restoration (R3 or mFRR): this reserve enables Elia to cope with a significant or systematic imbalance in the control area.

Tertiary reserves consist of reserved and non-reserved volumes. In the past, these non-reserved tertiary reserves (so called “free balancing bids”) were exclusively flexible volumes mainly coming from the large (spinning) power generation units (>25MW). The Bidladder project opened up this market of non-reserved R3 towards smaller units and demand response, in order to create a level playing field for all technologies to compete, both for TSO and DSO-connected assets.

The bidladder, a closer look

In essence, the BidLadder is a platform operated by Elia gathering different (kinds of) bids for balancing energy. In its ultimate form it will provide control engineers with an overall ranking for balancing energy, in particular all R3-related products, whether reserved or non-reserved. Opening market access to balancing service providers will give Elia greater liquidity in the balancing energy market, which is also positive for the community and in terms of integrating RES into the Belgian grid.

The BidLadder, combined with a transfer of energy (ToE) solution, enables BSPs like independent aggregators or grid users to offer Elia flexibility for balancing purposes, whereas today this option is only open to large generating facilities (such as CIPUs).A transfer of energy for the market of tertiary non-reserved control power is foreseen in April 2018.

This transfer of energy solution will ensure that market parties (i.e. BSPs), that are not necessarily suppliers or balancing responsible parties, can participate in the balancing mechanism by offering their flexibility to Elia

In a nutshell

Consumers and holders of decentralized generation unit (<25MW) who are able to react to a signal from Elia within 15 minutes for a period of at least 15 minutes.

Volume offered

At least a volume of 1 MW with 0,1MW increments (can be spread over multiple sites and offered with a partner).

How does Elia buy this service?

Offers are submitted via a portal for each quarter-hour of the day.

Availability of the service offered?

Thanks to its non-reserved character, the service only has to be available at the time of activation.

What’s in it for you?

If you are activated, Elia will pay you a fee based on the price you set.

In the interest of society

Opening up the balancing market to new sources of flexibility and bringing in new types of market actors to offer this flexibility to Elia, can only improve the liquidity of the balancing market. This will give Elia higher balancing volumes at lower prices, which will have a positive knock-on ‘welfare’ effect for society in general.


"The BidLadder-project combines multiple aspects of balancing market design with a contractual framework that is at a crossroads between several ongoing developments. The current pilot project is just a first step in a far more expansive, ongoing change."

Patrick Buijs,