No submissions on the draft determination were received. Accordingly, the Authority’s final determination under clause 8.61(9) of the Code is that Contact Energy was the causer of the under-frequency events on 11 and 15 June 2017.

The Authority’s reasons for this final determination, in both cases, are:

  1. the system operator has investigated the UFEs (in accordance with clause 8.60 of the Code), and has reported to the Authority that:
    1. the interruptions/reductions of energy occurred at the Taranaki Combined Cycle (Stratford) power station, which belongs to Contact
    2. no other asset was identified as having caused or potentially caused these UFEs
    3. in the system operator’s view, Contact is the causer of both UFEs
  2. in a reply to a system operator letter, Contact accepted that it was the causer of both UFEs
  3. having considered the system operator’s reports and the relevant elements of the Code, the Authority (based on the information available to it at this time) concurs with the system operator’s findings.

In accordance with clause 8.65 of the Code, the clearing manager rebates the event charges to relevant participants. The charges advised in the system operator’s report were $332,000 for the 11 June 2017 event, and $291,819 for the 15 June 2017 event.

This decision may not be disputed to the Rulings Panel after 28 December 2017