Waikato and Upper North Island Voltage Management Investigation

Region Map
Auckland population
1.5 M
...and increasing
Huntly coal generation
planned retirement date
Improved voltage support
to meet Auckland's needs

We need to continually operate, maintain and develop New Zealand's transmission network - the National Grid - to ensure we meet the ongoing electricity needs of New Zealanders.

A need to investigate

Recent and planned decommissioning of thermal generation plant at Otahuhu, Southdown and Huntly, and demand growth in Auckland, are expected to lead to voltage management issues in Waikato and the Upper North Island, including Auckland. The critical risks are transient under - and over-voltage events that could cause voltage collapse if not managed. Efficient voltage management is essential to the reliable delivery of power.

The voltage issues worsen with rising demand in Waikato and the Upper North Island, with the impact of the planned 'thermal decommissionings'.  

The critical 'need by' date is when Genesis Energy retire their Huntly coal generation plant, currently announced for 2022.

What are the potential solutions

There are many ways of supporting voltage including not only devices such as capacitors, synchronous condensers, statcoms and SVCs, but potentially also demand response and generation solutions.  Moreover, the issue is complex.  A portfolio of different assets – at various locations and commissioned at different times – rather than a single asset solution is needed. 

After three years of in-depth analysis, we are proposing a mix of reliable and economic non-transmission solutions, reactive power plant and a demand management scheme. We detail this in our June 2019 short-list consultation document and accompanying documents, which can be found below.