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Regulatory Investment Tests for Distribution

Under Clause 5.17 of the National Electricity Rules (NER), Jemena Electricity Network (JEN) and other distribution network service providers (DNSPs) are required to undertake Regulatory Investment Tests for Distribution (RIT-Ds) for some network investment projects to support consistent, clear and efficient planning processes within the National Electricity Market (NEM). Below is information on our completed, in progress and proposed upcoming RIT-D projects.

 

Completed RIT-D Projects

JEN has completed RIT-Ds for the following augmentation projects (construction status included):

JEN has completed RIT-Ds for the following replacement projects (construction status included):

 

In Progress RIT-D Projects

There are no RIT-Ds that are currently in progress.

 

Future RIT-D Projects

JEN is intending to commence the RIT-D process for the following augmentation projects within the forward five-year planning period with the following expected commencement dates:

  • East Preston (EP) conversion Stage 7 and Stage 8 (June 2024)
  • Brunswick Terminal Station - North Essendon Zone Substation 22 kV subtransmission loop capacity constraint (June 2025)
  • New Feeder SHM-013 to alleviate SHM-014 feeder thermal constraint (June 2024)
  • Coolaroo, Somerton and Kalkallo capacity constraint (October 2024)
  • Thomastown-NEI-North Heidelberg-NEL-Watsonia 66 kV loop capacity constraint (March 2025)
  • Sydenham and Sunbury area capacity constraint (June 2025)

In addition, JEN intends to commence the RIT-D process for the following replacement projects within the forward five-year planning period with the following commencement dates:

  • Coburg North Zone Substation (CN) switchgear and relay condition (June 2025)
  • Coburg South Zone Substation (CS) switchgear and relay condition (June 2026)

Further details on these future projects can be found in our 2023 Digital DAPR Map 
(note this can only be accessed using Google Chrome or Microsoft Edge).

The following table includes a list of replacement projects excluded from the RIT-D process because they satisfy the criteria for a committed project as defined in the AER’s RIT-D Application Guidelines on or before 30 January 2018. These completed projects have been identified in JEN's Distribution Annual Planning Reports from 2014 onwards.

Project Name

Project Description

Commissioning Date

Fairfield Zone Substation transformer replacement

Fairfield Zone Substation (FF) comprises three 22/6.6 kV 10/13.5 MVA transformers and three 6.6 kV buses supplying six JEN 6.6 kV feeder lines. The substation also supplies six CitiPower 6.6 kV feeder lines. FF supplies areas of Fairfield, Alphington and Ivanhoe.

The existing FF transformers were manufactured in 1955. Due to the age and condition of the transformers, as confirmed by paper samples taken from the winding leads of the No.1, No.2 and No.3 transformers in 2013 and 2014, the transformers require replacement to maintain acceptable levels of supply reliability.

To manage the risk associated with the aging transformers at FF, JEN will replace two of the transformers with 12/18 MVA 22/11/6.6 kV dual secondary winding units. The existing No. 3 10/13 MVA transformer will be retained as a hot spare.

May 2020

 

Preston Conversion Stage 6

Preston Zone Substation (P) comprises two 66/6.6 kV 20 MVA transformers and two 6.6 kV buses supplying five 6.6 kV feeder lines. P supplies areas of Preston. P was originally commissioned in the late 1950s. Due to the age and poor condition , many of the zone substation assets require replacement over the next five to ten years  to maintain acceptable levels of safety and supply reliability.

To ensure continued reliability and to avoid inefficient maintenance works and like-for-like replacements of poor-condition zone substation components over the next five to ten years, JEN developed a strategic plan to convert its distribution network from 6.6 kV to 22 kV in the Preston and East Preston. The conversion program commenced in 2008 and is planned to be completed in stages by around 2024.

The P conversion stage 6 project involves decommissioning the existing Preston Zone Substation and establishing a new Preston Zone Substation (PTN) consisting of two 66/22 kV 20/33 MVA transformers on the existing site.

April 2020

Essendon Zone Substation transformer replacement

Essendon Zone Substation (ES) comprises two 66/11 kV 20/27 MVA transformers and two 11 kV buses supplying ten 11 kV feeder lines. ES supplies areas of Essendon, Moonee Ponds, Ascot Vale and Niddrie.

The existing ES transformers were manufactured in 1965.  Due to the age and condition of the transformers, as confirmed by a paper sample degree of polymerisation test conducted on the No.1 transformer in 2013, the transformers require replacement within the forward planning period to maintain acceptable levels of supply reliability. The two transformers will be replaced with 66/11 kV 20/33 MVA modern equivalent units.

May 2020