A secure and reliable electricity supply is essential to Auckland's success.
There are three elements of a secure and reliable electricity supply:
Auckland relies on other parts of the country for most of its electricity generation and supply.
The national reliance on hydro-generated electricity helps reduce greenhouse gas emissions, but it makes us vulnerable during periods of drought.
Auckland is also vulnerable to potential failure of the transmission infrastructure which delivers electricity to the region.
The transmission network through Auckland supplies electricity to Northland. As the network crosses Auckland, electricity is transferred to local distribution lines via a series of exit points, including substations at Ōtāhuhu, Penrose and Mt Roskill.
Local distribution companies deliver electricity to homes and businesses. In Auckland, Vector and Counties Power have the responsibility of distributing electricity locally.
Future demand for electricity
Auckland's continued growth is reflected in projected increases in the region's electricity demand.
Transpower New Zealand reports that demand for the Auckland region is forecast to grow by an average 1.4 per cent per annum over the next 15 years, from 1904 MW in 2017 to 2360 MW by 2032. This is a measure of after diversity maximum demand (ADMD).
This is the same as the national average growth rate (Transpower New Zealand, 2017a).
The electrification of public transport systems and the growth in numbers of electric vehicles will further increase demand on Auckland's electricity system.
Future power systems will change as a result of emerging battery technology.
Battery technology offers opportunities to store electricity economically, close to where it is used. It can also store local sources of generation, such as rooftop solar, and smooth out the impacts that variable generation can have on the power system.
Longer-term, battery or other storage technologies installed in homes, businesses, vehicles, distribution networks and grid substations could alter electricity transmission by covering short-term imbalances in supply and demand.
This will mean that the power system could operate differently, with increased flexibility to schedule energy transfers and grid outages to optimise the use of the grid, grid generation and
distributed energy resources. (Transpower New Zealand, 2017b).
Transpower New Zealand (2017a). Transmission Planning Report July 2017
Transpower New Zealand (2017b). Battery Storage in New Zealand September 2017