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

0BInvestment Evaluation Summary
TNM-GS-809-0720
7.4 OPTION 4: COMPLETE REDEVELOPMENT OF KNIGHTS ROAD 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 with 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 $8.58 million ($June 2007).
7.4.2 BENEFITS
The benefits for this option are that it:
� would allow Transend to achieve the capital expenditure objectives;
� addresses the asset and safety issues associated with the 110 kV assets identified in section 4, in particular the
110 kV voltage transformers and post insulators;
� addresses other performance, reliability and design issues identified in section 4; and
� reduces the ongoing maintenance requirements and costs associated with the site.
7.4.3 DRAWBACKS
The option has the following drawbacks:
� higher capital cost than option 2.
7.4.4 CONCLUSION
This option is technically viable.
8 OPTION ESTIMATES
A comparison of the net present value of options is provided in Table 2.
Table 2 - Comparison of options considered
Option
Net present value of costs ($M June 2007)
1 Manage existing assets and defer replacement -$5.21
2 Replace selected assets in-situ -$4.71
3 Staged replacement of selected assets in-situ -$4.87
4 Complete redevelopment of Knights Road Substation 110 kV -$5.23
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