Far North electricity company Top Energy will spend $170 million over the next decade on its network, mainly for security of power supply.

Building an electricity network that keeps pace with technological developments and meets changing consumer behaviour is a key priority for Top Energy's $170m 10-year investment programme, chief executive Russell Shaw said.

Over the next decade the company will focus its investment programme on initiatives that enable greater flexibility in how it manages its network.

"We have natural advantages, such as the geothermal resource at Ngawha which we are developing, but our network is remote, largely rural, and dependent on a single high voltage, double circuit line supplied from Maungatapere. In fact, about one third of the network is uneconomic to run and remains unreliable in some areas," Shaw said.


Shaw said the company has embarked on an investment programme that will help address these issues to provide a reliable and resilient network.

Top Energy is expanding it's geothermal operation at Ngawha and that along with building a second line to Kaitaia are key to the long-term reliability of the network.

He said the company is also focused on new initiatives in the short term. The first is more diesel generators which can boost local supply.

"Over the next two years the company will install an additional 9MW of diesel generation to improve network security to customers fed from the single line to Kaitaia."

The second explores a number of alternative network options such as combining small generators, batteries and solar panels to create micro-grids to boost the local power supply without needing to invest in the replacement of costly and uneconomic lines infrastructure.

"This will increase the total diesel generation capacity distributed through the network to 15MW. Once completed the generation at Ngawha will produce 53MW of geothermal generation in the Far North with the opportunity to grow this to 81MW in 2025. This will mean that power will be exported from the region 100 per cent of the time.

The diesel generators will cost $10 million which, Shaw said, is significantly quicker to implement than the second line to Kaitaia, which is delayed due to property acquisition rights with landowners.

"The advantage of back up localised generation has already been demonstrated at Taipa where the supply has been maintained during outages affecting the wider network.

"Generators also introduce a degree of flexibility and options into how we manage the network as they can be relocated to areas as required."

Two 1MW diesel generators will be installed at Omanaia over the summer so that power can be maintained to 1600 customers on the south west side of the Hokianga while the substation and 33kV line are upgraded.

Once this project is finished the generators, along with additional generators yet to be bought, will be relocated to Kaitaia where they will be used to secure supply to the northern network which supplies 10,000 customers.

"This is a temporary solution until we are able to build our second 110kV line into Kaitaia."

Shaw said the penetration of solar power use in the Far North is the second highest across all New Zealand electricity lines companies.

"We have 600 customer connections who have installed solar panels, creating a total of 2MW of embedded solar generation, which means they can export power back to the network."