Electricity Asset Management Plan 2019-2029
191
Vector Limited://
DESCRIPTION
DISCUSSION OF OPTION
ESTIMATED COST (NPV IF APPLICABLE)
STATUS
Option 1: Do nothing – do not address the need to replace conductors
Not undertaking a replacement programme will exacerbate the increasing trend of failure of smaller conductors with a commensurate increase in the risk of harm posed to the public of falling conductors as the population continues to age over the AMP period. The volume of conductors with poor health and high probability of failure will continue to increase and reach a point where it will be difficult to maintain the population of OH conductors to an asset health score below 7 19 . Selecting this option will also result in an increase in SAIFI, reduction in service levels and the customer’s experience of the quality of Vector’s electricity supply will further deteriorate. There are certain areas in which undergrounding is a more effective cost option than OH line refurbishment and reconductoring but in most cases undergrounding is considerably more expensive, up to four times more, than refurbishing and reconductoring an OH line. However, each project is considered on a case by case basis and where undergrounding is the better option it will be implemented To prevent the risks posed by the ‘Do nothing’ approach a long term proactive programme of works must be undertaken to replace conductors with a high probability of failure. The investment programme as proposed below will replace over the AMP period conductors that presently (at the start of the AMP period) has a health index of 7 and above
Rejected
Option 2: Underground the network
Rejected as a blanket option
but will be used if it is practical
Option 3: Replace small diameter conductors based on asset health and criticality
$116.50M Selected
PROPOSED INVESTMENT SUMMARY ($MILLION NOMINAL)
DESCRIPTION
FY20
FY21
FY22
FY23
FY24
FY25
FY26
FY27
FY28
FY29 TOTAL
Auckland overhead conductor renewal Northern overhead conductor renewal
2.00
3.00
4.00
6.00
6.00
6.00
6.00
6.00
6.00
6.00
51.00
2.00
4.50
5.00
7.50
7.50
7.50
7.50
8.00
8.00
8.00
65.50
Total CAPEX
4.00
7.50
9.00
13.50
13.50
13.50
13.50
14.00
14.00
14.00
116.50
AUCKLAND AND NORTHERN NETWORK RESILIENCE IMPROVEMENTS
NEEDS STATEMENT Vector’s approach to asset management recognises that climate change poses a risk to our assets and operation. Wind gusts up to 215 kilometres per hour were recorded during the intense April 2018 storms. The level of damage across our network was unprecedented and offered a stark reminder of the type of event that may become more frequent with climate change, and that could threaten the reliability of electricity distribution in the future. According to a National Institute of Water and Atmospheric Research study in 2017, environmental events such as extreme rainfall, severe droughts, wildfires and wind with increased speeds could hit Auckland in years to come. Environmental factors including climate change in combination with natural hazards is forecast to impact each part of the electricity system differently but is more pronounced on OH networks and will ultimately affect customers directly. As sustained wind speeds on the Vector network exceeds 70 km/h there is a significant increase in the duration of outages, customer minutes lost and the number of customers affected. There is a need for capital investment that specifically targets resilience aspects to make the network more reliable during severe environmental events.
―
19 Refer our CBARM model for an explanation of health index scores
Made with FlippingBook - professional solution for displaying marketing and sales documents online