Organization
New Zealand's electricity sector is split into six distinct parts:
Generation – Generation companies generate electricity at power stations, injecting into either transmission lines (grid-connected generation) or distribution lines (embedded generation). The electricity generated is sold via the wholesale market to retailers. Numerous companies generate power, but 92 percent of the generation sector is dominated by five companies: Contact Energy, Genesis Energy, Meridian Energy, Mercury Energy and Trustpower.
Transmission – Transpower, a state-owned enterprise, operates the national transmission network, consisting of 11,000 km of high voltage lines that connect generating stations with the grid, and supply distribution networks and large industrial consumers (direct consumers) in each of New Zealand's two main islands. The HVDC Inter-Island is a high voltage direct current link which connects the transmission networks of the two islands. Transpower as System Operator manages the electricity system in real time to ensure generation matches demand, in accordance with the rules of the electricity market.
Distribution – Distribution companies operate 150,000 km of medium and low-voltage lines interconnecting grid exit points with consumers and embedded generation. There are 29 distribution companies each serving a set geographic area.
Retail – Retail companies buy electricity from generators and on-sell it to consumers. Numerous companies retail electricity, including many generating companies, but 95 percent of the retail sector is dominated by the five big generation companies: Contact Energy, Genesis Energy, Mercury Energy, Meridian Energy and Trustpower.
Consumption – Nearly two million consumers take electricity from the distribution networks or the transmission network and buy electricity from retailers for their use. Consumers range from typical households, which consume on average 7 MWh per year, to the Tiwai Point aluminium smelter, which consumed 5,000 GWh in the 2017 year, representing 13% of total energy demand.[17]
Regulation – New Zealand's Electricity Authority (formerly the Electricity Commission) is responsible for regulation of the New Zealand electricity market. Transmission and distribution are regulated by the Commerce Commission. Policy and consumer protection is managed by the Ministry of Business, Innovation and Employment, and the promotion of energy efficiency is led by the Energy Efficiency and Conservation Authority.