Transend - Appendix 5 Renewal capital expenditure - Australian ...

The drawbacks for this option are that it:
� results in a higher initial capital cost than option 1;
0BInvestment Evaluation Summary
TNM-GS-809-0720
� results in a higher overall capital cost than option 2, primarily due to contractor remobilisation and increased internal
costs;
� does not align with Transend’s policy to utilise dead tank circuit breakers when replacing 110 kV live tank current
transformers and circuit breakers for two 110 kV bays;
� reduced efficiencies in project delivery, in particular co-ordination of works associated with the Avoca Substation
transformer T2 installation project and asset replacement works; and
� will need additional transmission circuit outages to undertake the works.
7.3.4 CONCLUSION
This option is technically viable.
7.4 OPTION 4: COMPLETE REDEVELOPMENT OF PALMERSTON SUBSTATION
110 KV
7.4.1 SCOPE
The scope for this option includes:
� in-situ replacement of the existing live tank circuit breakers with dead tank units that have integral current
transformers;
� replacement of 110 kV disconnectors in situ;
� replacement of gantry structures;
� replacement of protection and control schemes; and
� implement revised maintenance practices.
The capital cost of this option is $12.49 million ($June 2007).
7.4.2 BENEFITS
The benefits for this option are that it:
� allows Transend to achieve the capital expenditure objectives;
� addresses safety issues associated with the 110 kV assets identified in Section 4 of this document, in particular the
110 kV voltage transformers and post insulators;
� addresses other performance, reliability and design issues identified in Section 4 of this document;
� improves operational functionality as new 110 kV disconnectors would be motorised and capable of remote
operation; and
� reduces the ongoing maintenance requirements and costs associated with the site.
7.4.3 DRAWBACKS
The drawbacks for this option are that it:
� would need outages of an extended duration for each transmission circuit because it would be required to replace
110 kV disconnectors and other infrastructure; and
� would require a higher capital cost than option 2.
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