# Commission Regulation (EU) 2017/1485 of 2 August 2017 establishing a guideline on electricity transmission system operation (Text with EEA relevance), Article 160: RR dimensioning

Extent: E+W+S+N.I.

1. All TSOs of an LFC block shall have the right to implement a reserve replacement process.
2. To comply with the FRCE target parameters referred to in Article 128, all TSOs of a LFC block with a RRP, performing a combined dimensioning process of FRR and RR to fulfil the requirements of Article 157(2), shall define RR dimensioning rules in the LFC block operational agreement.
3. The RR dimensioning rules shall comprise at least the following requirements:
(a) there shall be sufficient positive reserve capacity on RR to restore the required amount of positive FCR and positive FRR;
(b) there shall be sufficient negative reserve capacity on RR to restore the required amount of negative FCR and negative FRR;
(c) there shall be sufficient reserve capacity on RR, where this is taken into account to dimension the reserve capacity on FRR in order to respect the FRCE quality target for the period of time concerned; and
(d) compliance with the operational security within a LFC block to determine the reserve capacity on RR.
4. All TSOs of an LFC block may reduce the positive reserve capacity on RR of the LFC block, resulting from the RR dimensioning process, by developing a RR sharing agreement for that positive reserve capacity on RR with other LFC blocks in accordance with the provisions of Title 8 of Part IV. The control capability receiving TSO shall limit the reduction of its positive reserve capacity on RR in order to:
(a) guarantee that it can still meet its FRCE target parameters set out in Article 128;
(b) ensure that operational security is not endangered; and
(c) ensure that the reduction of the positive reserve capacity on RR does not exceed the remaining positive reserve capacity on RR of the LFC block.
5. All TSOs of a LFC block may reduce the negative reserve capacity on RR of the LFC block, resulting from the RR dimensioning process, by developing a RR sharing agreement for that negative reserve capacity on RR with other LFC blocks in accordance with the provisions of Title 8 of Part IV. The control capability receiving TSO shall limit the reduction of its negative reserve capacity on RR in order to:
(a) guarantee that it can still meet its FRCE target parameters set out in Article 128;
(b) ensure that operational security is not endangered; and
(c) ensure that the reduction of the negative reserve capacity on RR does not exceed the remaining negative reserve capacity on RR of the LFC block.
6. Where a LFC block is operated by more than one TSO and if the process is necessary for the LFC block, all TSOs of that LFC block shall specify in the LFC block operational agreement the allocation of responsibilities between the TSOs of different LFC areas for the implementation of the dimensioning rules set out in paragraph 3.
7. A TSO shall have sufficient reserve capacity on RR in accordance with the RR dimensioning rules at any time. The TSOs of a LFC block shall specify in the LFC block operational agreement an escalation procedure for cases of severe risk of insufficient reserve capacity on RR in the LFC block.

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Source: https://www.legislation.gov.uk/eur/2017/1485/article/160 (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-1485/article-160
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.