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

Latest updates

We have added all submissions on the June 2019 short-list consultation document plus a summary of submissions and our responses, which can be found here.

We are currently preparing our Major Capital Proposal submission to the Commerce Comission for November 2019.

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 such as by using capacitors, synchronous condensers, statcoms and SVCs, but potentially also demand response and generation solutions.  Moreover, the issue is complex and 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 our progress in our consultation documents, accompanying reports and updates, which can be found below.