Northpower has started upgrading its sub stations around Whangārei and Kaipara, here with stations programme manager Irfan Shahzad at the Ngunguru sub station. Photo / Tania Whyte
Northpower has started upgrading its sub stations around Whangārei and Kaipara, here with stations programme manager Irfan Shahzad at the Ngunguru sub station. Photo / Tania Whyte
Northpower is spending just over $18 million replacing ageing transformers around Whangārei and Kaipara over the next decade for better electricity supply security.
Growth in areas such as Parua Bay, Ngunguru and Hikurangi is also a key reason for major investment in ageing transformers as per the lines' company's 10-yearasset management programme.
Ageing switchboards within the sub-stations will also be replaced, Northpower customer experience manager Rachel Wansbone said.
Upgrade of the sub-stations at Ngunguru, Parua Bay and Hikurangi are the first of seven sub-stations to be upgraded over 10 years.
Load growth is also expected as more electric vehicles are charged on the Northpower network.
"We will be upgrading them to the new safer gas-insulated vacuum-sealed circuit breakers, which are safer to operate than the older oil-insulated circuit breakers. Seven switchboard upgrades are planned over the coming 10 years," Wansbone said.
The Hikurangi sub-station will have two new transformers installed, doubling the capacity of the sub-station to allow for growth in the area and giving higher reliability of supply for residents in the area.
The switchboards are also being upgraded, which will improve reliability and operator safety. Any potential environmental impact would be mitigated by installing bunding for oil spills, better fire and earthquake resilience and a reduction in noise, she said.
The $4.8m project has been ongoing for nearly a year.
Northpower stations programme manager Irfan Shahzad at the Ngunguru sub station where upgrade work is in full swing.
Photo / Tania Whyte
The Hikurangi sub-station currently serves 3,230 customers, and by 2031 Northpower expects that number to increase to about 3,895.
The Ngunguru sub-station will also get a new transformer and switchboard and upgraded from 3.75 megawatt to 5 MW.
A new building is being built to house the switchboards, bringing the equipment indoors. Work has begun and should be completed around March 2022.
The number of Northpower customers relying on the Ngunguru sub-station is projected to grow from the present 2,050 to 2,475 in the next decade.
With high population growth in the area, Parua Bay sub-station is also getting an upgrade.
The current 3.75MW transformer installed in 1956 will be changed to 5MW transformer and bunding, fire and earthquake protection and noise emission will be improved as part of a $1.2m investment.
The project started just over a week ago and has a target date for completion of April 2022.
The number of power users in Parua Bay is projected to rise from 2,160 to 2,630.
Northpower will spend $2.7m upgrading the Kensington sub-station next year and work will involve reconfiguring the high voltage feeders that come from the transpower grid as well as upgrading transformers and circuit breakers.
A second 10 MVA transformer and switch upgrade costing $3.1m is being planned at the Bream Bay sub-station while $6m will be spent moving switchgear indoors in Maungatapere.
The lines company will replace transformers and switchgear at its Ruawai sub-station at a cost of $1.9m.
