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.
Waikato and Upper North Island Voltage Management Investigation
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. Efficient voltage management is essential to the reliable delivery of power.
The impact of the 'thermal decommissionings' has been studied in depth by Transpower.
The critical 'need by' date is when Genesis Energy retire their Huntly coal generation plant, currently announced for 2022. Given the lead time for new transmission equipment we have started investigating the long-term solution.
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 expected to be required.
Our initial conservative expectation was to run a non-transmission solution procurement process in 2017, timed to enable us to defer major transmission investment otherwise needed for 2022. Our latest analysis indicates that we can defer both by three to four years.