AMP 2019-2029

Electricity Asset Management Plan 2019-2029

161

Vector Limited://

FORECAST INVESTMENT SUMMARY ($MILLION NOMINAL)

DESCRIPTION

FY20

FY21

FY22

FY23

FY24

FY25

FY26

FY27

FY28

FY29 TOTAL

Establish a Wiri West zone substation

0.20

2.70

4.34

4.34

11.58

11kV feeder reinforcement – Great South Rd

1.76

1.76

Total CAPEX

0.20

2.70

4.34

4.34

0.00

0.00

0.00

0.00

1.76

0.00

13.34

NEEDS STATEMENT – TAKANINI Takanini covers the urban areas of Manurewa, Takanini and Papakura townships, extending east to the more remote areas of Clevedon, Maraetai, Beachlands and Waiheke Island. Waiheke Island has a relatively static load of about 12MVA, supplied via two 33kV subtransmission cables from Maraetai. These cables can provide N-1 security but any damage to the undersea portion of these circuits takes considerable time to repair, leaving the supply to the island dependent on a single circuit. Provision has been made for the installation of third cable between Waiheke and Maraetai to lessen this asymmetric risk but project as presented represents an upper cost threshold for delivering a workable solution. The intention is to look at other local solutions that may deliver a similar outcome but utilising new technology and at a lower cost

11kV distribution feeder upgrades are planned for Whitford Rd, Papakura and Waiheke.

TARGETED OUTCOMES

CUSTOMER EXPERIENCE

SAFETY

RELIABILITY

RESILIENCE

OPERATIONAL EFFICIENCY

CYBER SECURITY AND PRIVACY

OPTIONS ASSESSMENT For major projects, i.e. above $4M (level to be confirmed), include the following in this section: Technical feasibility, economic analysis, OPEX and CAPEX costs, net present value or net present cost, service levels, risks, etc.

DESCRIPTION

DISCUSSION OF OPTION

ESTIMATED COST (NPV IF APPLICABLE)

STATUS

Address the risk of both undersea sub-transmission cables to Waiheke incurring concurrent damage

Option 1: Install a third subtransmission cable to Waiheke. The 12MW electrical demand on Waiheke is delivered by two undersea subtransmission cables. The load can be supported by one cable but repairs to the faulty cable may take many weeks stretching to months. Having a circuit out-of-service for an extended period of time increases the likelihood of a second cable failure within that outage interval. The existing cables are 1970/1987 vintage PILC cables. A third cable across the marine portion of the route would largely mitigate this risk Option 2: Non-network solution. The cost of a cable to provide N-2 security across the marine section for a HILP event is significant. The implementation of a multi- facetted local solution comprising large-scale solar generation, load management, network batteries supported by a diesel backup may be a more cost effective solution. However a viable solution needs to cost less than the cost of Option 1.

$7.5M Under analysis

Under analysis

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