Tender of balancing power

Control reserve is required by the transmission system operator to ensure a balance between electricity generation and consumption at all times. Since 1 December 2006, TenneT has been procuring minute reserve capacity and, since 1 December 2007, primary and secondary control reserve capacity in accordance with the specifications of the Federal Network Agency (BNetzA) via the joint internet platform of the German transmission system operators (www.regelleistung.net).

Until these dates, the different types of control reserve were procured through separate tenders. Potential providers of the various types of control reserve can pre-qualify with TenneT for the provision and supply of control reserve. This involves checking whether the technical requirements for providing these services are met. The documents required for participation in the prequalification process and further information can be found on the joint internet platform www.regelleistung.net

Control service (FCR)

As part of FCR procurement, there are daily tenders for control services, for which bids can be submitted by 8 a.m. the day before. The product duration for FCR is four hours, starting with the time slot from midnight to 4 a.m. and ending with the time slot from 8 p.m. to midnight. This means that six time slots can be bid on per day. Unlike aFRR and mFRR, FCR is a symmetrical product. This means that suppliers must be able to deliver both positive and negative FCR. In addition, remuneration is pay-as-cleared, which means that all suppliers receive the highest price awarded.

Balancing power (aFRR and mFRR)

First, the control power is auctioned on the control power market (RLM) on the previous day. The market for aFRR closes at 9 a.m. and the market for mFRR closes at 10 a.m. The RLM ensures that sufficient power is offered in the subsequent auctions for the procurement of control power on the control power market (RAM) to meet demand. Every supplier awarded a contract on the RLM is obliged to offer control work bids in the amount of their awarded control power. In addition, the RLM auction result serves as a backup in case the RAM fails. Every bid awarded on the RLM is remunerated at the offered control power price. A working price can, but does not have to, be specified on the RLM. This is then transferred by the TSO to the RAM, so that additional active participation in the RAM is no longer necessary. However, the voluntarily submitted working price can be adjusted for each quarter hour until gate closure. This is because while the product length for the RLM is four hours, bids can be submitted individually for each quarter hour of a day in the RAM.

Regular work (aFRR and mFRR)

After the RLM has closed, the regular market (RAM) opens for the current delivery day. All quarter hours of the delivery day are procured individually on the RAM. The RAM closes 25 minutes before the start of each quarter hour of delivery. All regular bids offered are accepted on the RAM, regardless of whether they were mandatory due to an award on the RLM or voluntary. 
This allows for additional flexibility or for capacity that was not awarded on the previous day to participate in the RAM. A capacity price is only paid to bids that are awarded on the RLM. All submitted regular work bids are transferred to a merit order list and called in ascending order according to the working price. The activated regular work is settled according to the marginal price procedure. The marginal prices are determined by the platforms, MARI (mFRR labour market) for mFRR and PICASSO & IGCC (aFRR labour market) for aFRR.

More detailed information on the tender, dimensioning and an overview of historical demand for FCR, aFRR and mFRR can be found at www.regelleistung.net

If you have any questions on this topic, please contact Mr Riedel and Mr Strobel at regelleistung(at)tennet.eu