Market message on changed LTA configuration

Dear market parties,

CWE TSOs would like to inform you about a change in the configuration of the LTA coverage/inclusion algorithm that has been implemented in 2017.

As has been described in the CWE FB MC Approval Document in paragraph 4.2.6 and annex 16.6, TSOs apply a 'LTA coverage' method to enlarge the FB domain as to cover/include long term allocated capacities when they are not fully encompassed by the DA FB domain. LTA coverage can be ensured by either enlarging a critical branch (CB), or applying virtual CBs.

Some TSOs have changed the configuration from Enlarged to the Virtual CBs setting. This change was done on the 20th of March 2017 (for Business Day 22th of March onward).

This change is relevant for SPAIC studies that make use of reference days from before 22th of March 2017. Therefore, the capacity domains of the historical days for the reference scenarios will be recalculated based on the currently applied method of applying virtual CBs. By doing so, CWE TSOs make sure that the SPAIC study results reflect in the best possible way the impact of future changes.

Whether or not TSOs historically applied the LTA coverage algorithm and if so, whether they enlarged a critical branch or made use of virtual CBs for Business Days before 22th of March 2017 can be observed via the JAO Utility tool in the published elements ID of the fixed all anonymized CBCOs[1].

Based on the published ID it can be observed whether the Enlarged (only one ID) or Virtual CBs (multiple incremental IDs) have originally been applied by each TSO.

Best Regards,

CWE TSOs

[1] See CWE Publication Handbook on JAO, http://utilitytool.jao.eu/CWEMC_PublicationHandbook_1.5.pdf, page 9