Electricity sector in New Zealand
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The electricity sector in New Zealand uses mainly
renewable energy Renewable energy is energy that is collected from renewable resources that are naturally replenished on a human timescale. It includes sources such as sunlight, wind, the movement of water, and geothermal heat. Although most renewable energy ...
, such as
hydropower Hydropower (from el, ὕδωρ, "water"), also known as water power, is the use of falling or fast-running water to Electricity generation, produce electricity or to power machines. This is achieved by energy transformation, converting the Pot ...
,
geothermal power Geothermal power is electrical power generated from geothermal energy. Technologies in use include dry steam power stations, flash steam power stations and binary cycle power stations. Geothermal electricity generation is currently used in 2 ...
and increasingly wind energy. , 82% of electricity is generated from renewable sources, making
New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
one of the countries with the lowest
carbon dioxide emissions Greenhouse gas emissions from human activities strengthen the greenhouse effect, contributing to climate change. Most is carbon dioxide from burning fossil fuels: coal, oil, and natural gas. The largest emitters include coal in China and lar ...
from
electricity generation Electricity generation is the process of generating electric power from sources of primary energy. For electric utility, utilities in the electric power industry, it is the stage prior to its Electricity delivery, delivery (Electric power transmi ...
. Electricity demand grew by an average of 2.1% per year from 1974 to 2010 but decreased by 1.2% from 2010 to 2013. The
electricity market In a broad sense, an electricity market is a system that facilitates the exchange of electricity-related goods and services. During more than a century of evolution of the electric power industry, the economics of the electricity markets had un ...
is regulated by the Electricity Authority. Electricity lines businesses, including Transpower and the distribution lines companies, are regulated by the Commerce Commission. Control is also exerted by the minister of energy in the
New Zealand Cabinet The Cabinet of New Zealand ( mi, Te Rūnanga o te Kāwanatanga o AotearoaTranslated as: "The Rūnanga (literally 'Council') of the Government of New Zealand") is the New Zealand Government's body of senior Ministers in the New Zealand Governmen ...
, though the minister for state-owned enterprises and the minister for climate change also have some powers by virtue of their positions and policy influence in the government.


History

In New Zealand electricity was first generated within factories for internal use. The first generation plant where power was transmitted to a remote location was established at
Bullendale Bullendale is an abandoned mining settlement in Otago, New Zealand. It is the site of New Zealand's first industrial hydro-electric power plant. Located in rugged and remote countryside, it has survived to become of historical significance, and sev ...
in
Otago Otago (, ; mi, Ōtākou ) is a region of New Zealand located in the southern half of the South Island administered by the Otago Regional Council. It has an area of approximately , making it the country's second largest local government reg ...
in 1885, to provide power for a twenty
stamp battery Stamp or Stamps or Stamping may refer to: Official documents and related impressions * Postage stamp, used to indicate prepayment of fees for public mail * Ration stamp, indicating the right to rationed goods * Revenue stamp, used on documents to ...
at the Phoenix mine. The plant used water from the nearby Skippers Creek, a tributary of the
Shotover River The Shotover River ( mi, Kimiākau) is located in the Otago region of the South Island of New Zealand. The name correctly suggests that this long river is fast flowing, with numerous rapids. The river flows generally south from the Southern Alps ...
. Reefton on the West Coast became the first electrified town in 1888 after the Reefton Power Station was commissioned, while the first sizable power station—the
Horahora Power Station Horahora Power Station was an early hydroelectric power station on the Waikato River in New Zealand. It was the country’s first large-scale power station, completed in 1913. Initially built to service a gold mine, the power station was expande ...
—was built for the Waihi gold mines at Horahora on the Waikato River. This set a precedent that was to dominate New Zealand's electricity generation, with
hydropower Hydropower (from el, ὕδωρ, "water"), also known as water power, is the use of falling or fast-running water to Electricity generation, produce electricity or to power machines. This is achieved by energy transformation, converting the Pot ...
becoming and remaining the dominant source.''New Zealand Historical Atlas''; McKinnon, Malcolm (Editor); David Bateman, 1997, Plate 88 From 1912 to 1918, the Public Works Department issued licenses for many local power stations. By 1920, there were 55 public supplies, with 45  megawatts of generating capacity between them. Early public electricity supplies used various
voltage Voltage, also known as electric pressure, electric tension, or (electric) potential difference, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to m ...
and current standards. The 230/400-
volt The volt (symbol: V) is the unit of electric potential, electric potential difference (voltage), and electromotive force in the International System of Units (SI). It is named after the Italian physicist Alessandro Volta (1745–1827). Defi ...
50-
hertz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that on ...
three-phase system was chosen as the national standard in 1920. At that time, 58.6% of the country's generating capacity used the 50 Hz
three-phase Three-phase electric power (abbreviated 3φ) is a common type of alternating current used in electricity generation, Electric power transmission, transmission, and Electric power distribution, distribution. It is a type of polyphase system empl ...
system; 27.1% used
direct current Direct current (DC) is one-directional flow of electric charge. An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor such as a wire, but can also flow through semiconductors, insulators, or even ...
systems while 14.3% used other
alternating current Alternating current (AC) is an electric current which periodically reverses direction and changes its magnitude continuously with time in contrast to direct current (DC) which flows only in one direction. Alternating current is the form in whic ...
standards. While industrial use quickly took off, it was only government programmes in the first two-thirds of the 20th century that caused private demand to climb strongly as well. Rural areas were particular beneficiaries of subsidies for electrical grid systems, where supply was provided to create demand, with the intention of modernising the countryside. The results were notable; in the 1920s, electricity use increased at a rate of 22% per year. In fact, the "load building" programmes were so successful that shortages started to occur from 1936 on, though a large number of new power stations built in the 1950s enabled supply to catch up again. After the massive construction programmes had created a substantial supply of energy not dependent on international fossil fuel prices, New Zealand became less frugal with its energy use. While in 1978 its energy consumption per unit of economic output hovered around the average of all
OECD The Organisation for Economic Co-operation and Development (OECD; french: Organisation de coopération et de développement économiques, ''OCDE'') is an intergovernmental organisation with 38 member countries, founded in 1961 to stimulate e ...
countries, during the 1980s New Zealand dropped far behind, increasing its energy use per economic unit by over 25%, while other nations slowly reduced their energy usage levels. Based on this economic comparison, in 1991 the country was the second-least energy-efficient of 41 OECD countries.''New Zealand Historical Atlas'' – McKinnon, Malcolm (Editor); David Bateman, 1997, Plate 98 All of the government's energy assets originally came under the Public Works Department. From 1946, the management of generation and
transmission Transmission may refer to: Medicine, science and technology * Power transmission ** Electric power transmission ** Propulsion transmission, technology allowing controlled application of power *** Automatic transmission *** Manual transmission *** ...
came under a new department, the State Hydro-Electric Department (SHD), renamed in 1958 as the New Zealand Electricity Department (NZED). In 1978, the Electricity Division of the Ministry of Energy assumed responsibility for electricity generation, transmission, policy advice and regulation.
Distribution Distribution may refer to: Mathematics *Distribution (mathematics), generalized functions used to formulate solutions of partial differential equations * Probability distribution, the probability of a particular value or value range of a vari ...
and retailing was the responsibility of local electric power boards (EPBs) or municipal electricity departments (MEDs). New Zealand's electrical energy generation, previously
state-owned State ownership, also called government ownership and public ownership, is the ownership of an industry, asset, or enterprise by the state or a public body representing a community, as opposed to an individual or private party. Public ownersh ...
as in most countries, was corporatised, deregulated and partly sold off over the last two decades of the twentieth century, following a model typical in the
Western world The Western world, also known as the West, primarily refers to the various nations and state (polity), states in the regions of Europe, North America, and Oceania.
. However, much of the generation and retail sectors, as well as the entire transmission sector, remains under government ownership as
state-owned enterprises A state-owned enterprise (SOE) is a government entity which is established or nationalised by the ''national government'' or ''provincial government'' by an executive order or an act of legislation in order to earn profit for the governmen ...
. The
Fourth Labour Government The Fourth Labour Government of New Zealand governed New Zealand from 26 July 1984 to 2 November 1990. It was the first Labour government to win a second consecutive term since the First Labour Government of 1935 to 1949. The policy agenda o ...
corporatised the Electricity Division as a State Owned Enterprise in 1987, as the
Electricity Corporation of New Zealand The Electricity Corporation of New Zealand Ltd (ECNZ) is a New Zealand state-owned enterprise (SOE) formed on 1 April 1987, as a transition entity in the process of deregulating the New Zealand electricity market. Most of ECNZ's remaining liabil ...
(ECNZ), which traded for a period as Electricorp. The Fourth National Government went further with the Energy Companies Act 1992, requiring EPBs and MEDs to become commercial companies in charge of distribution and retailing. In 1994, ECNZ's transmission business was split off as Transpower. In 1996, ECNZ was split again, with a new separate generation business, Contact Energy being formed. The Fourth National Government privatised Contact Energy in 1999. The Electricity Industry Reform Act 1998 required the separation of ownership between lines and energy businesses (either generation or supply). As a result, most of the former Electric Power Boards and Municipal Electricity Departments established electricity distribution businesses, and sold their electricity retail businesses, typically to generating companies. From April 1999, the remainder of ECNZ was split again, with the major assets formed into three new state-owned enterprises (Mighty River Power (now
Mercury Energy Mercury NZ Limited is a New Zealand electricity generation and multi-product utility retailer of electricity, gas, broadband and mobile telephone services. All the company's electricity generation is renewable. In August 2021, Mercury acquired ...
), Genesis Energy and Meridian Energy) and with the minor assets being sold off.
MBIE The Ministry of Business, Innovation and Employment (MBIE; mi, Hīkina Whakatutuki) is the public service department of New Zealand charged with "delivering policy, services, advice and regulation" which contribute to New Zealand's economic p ...
published a chronology of reforms up to 2015. Marked "This document outlines the main developments in New Zealand's electricity reforms since the mid-1980s."


Organisation

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 Wholesaling or distributing is the sale of goods or merchandise to retailers; to industrial, commercial, institutional or other professional business users; or to other wholesalers (wholesale businesses) and related subordinated services. In g ...
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 Mercury NZ Limited is a New Zealand electricity generation and multi-product utility retailer of electricity, gas, broadband and mobile telephone services. All the company's electricity generation is renewable. In August 2021, Mercury acquired ...
and
Trustpower Manawa Energy Limited, formerly Trustpower, is a New Zealand electricity generation company that offers bespoke electricity products to commercial and industrial customers across New Zealand. Manawa Energy has 26 hydro-electricity schemes, with a ...
. * Transmission – Transpower, a
state-owned enterprise A state-owned enterprise (SOE) is a Government, government entity which is established or nationalised by the ''national government'' or ''provincial government'' by an executive order or an act of legislation in order to earn Profit (econom ...
, 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 A high-voltage direct current (HVDC) electric power transmission system (also called a power superhighway or an electrical superhighway) uses direct current (DC) for electric power transmission, in contrast with the more common alternating curren ...
link which connects the transmission networks of the two islands. Transpower as
System Operator A sysop (; an abbreviation of system operator) is an administrator of a multi-user computer system, such as a bulletin board system (BBS) or an online service virtual community.Jansen, E. & James,V. (2002). NetLingo: the Internet dictionary. Netl ...
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. * 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.


Regulation and policy

Renewable energy sources generate much of the nation's electricity, with the New Zealand energy industry for example reporting a 75% share in 2013. The Fifth Labour Government of New Zealand had the goal of increasing this to 90% by 2025, the subsequent
Fifth National Government Neville Chamberlain formed the Chamberlain war ministry in 1939 after declaring war on Germany. Chamberlain led the country for the first eight months of the Second World War, until the Norway Debate in Parliament led Chamberlain to resign a ...
put priority on security of supply. New Zealand's Labour government introduced a number of measures in the 2000s as part of the vision of New Zealand becoming
carbon neutral Carbon neutrality is a state of net-zero carbon dioxide emissions. This can be achieved by balancing emissions of carbon dioxide with its removal (often through carbon offsetting) or by eliminating emissions from society (the transition to the "p ...
by 2020, and intended to collect levies for
greenhouse gas emissions Greenhouse gas emissions from human activities strengthen the greenhouse effect, contributing to climate change. Most is carbon dioxide from burning fossil fuels: coal, oil, and natural gas. The largest emitters include coal in China and lar ...
from 2010 onwards, to be added to power prices depending on the level of emissions. However, the incoming National government quickly
table Table may refer to: * Table (furniture), a piece of furniture with a flat surface and one or more legs * Table (landform), a flat area of land * Table (information), a data arrangement with rows and columns * Table (database), how the table data ...
d legislation to repeal some of these measures, such as obligatory targets for
biofuel Biofuel is a fuel that is produced over a short time span from biomass, rather than by the very slow natural processes involved in the formation of fossil fuels, such as oil. According to the United States Energy Information Administration (E ...
percentages, a ban on construction of new fossil fueled generation plants and a ban on future sales of
incandescent light bulb An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated until it glows. The filament is enclosed in a glass bulb with a vacuum or inert gas to protect the filament from oxida ...
s. From 1 January 2010, the energy sector was required to report greenhouse gas emissions under the
New Zealand Emissions Trading Scheme The New Zealand Emissions Trading Scheme (NZ ETS) is an all-gases partial-coverage uncapped domestic emissions trading scheme that features price floors, forestry offsetting, free allocation and auctioning of emissions units. The NZ ETS was fir ...
(NZETS). From 1 July 2010, the energy sector had formal compliance obligations to buy and surrender one emission unit for every two tonnes of reported emissions. As of December 2011, there were 78 energy firms compulsorily registered in the NZETS and five voluntary participants. Energy sector firms in the NZETS do not receive a free allocation of emissions units and they are expected to pass on to their customers the costs of buying emission units. In April 2013, the Labour Party and the
Green Party A green party is a formally organized political party based on the principles of green politics, such as social justice, environmentalism and nonviolence. Greens believe that these issues are inherently related to one another as a foundation ...
said if they were to win the 2014 general election, they would introduce a single buyer of electricity akin to
Pharmac The Pharmaceutical Management Agency (Māori: ''Te Pātaka Whaioranga''), better known as Pharmac, is a New Zealand Crown entity that decides, on behalf of Te Whatu Ora – Health New Zealand, which medicines and pharmaceutical products are s ...
(the single buyer of pharmaceutical drugs in New Zealand), in order to cut retail costs. The Government responded by calling it "economic vandalism", comparing it to the
Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...
, but Greens co-leader Russel Norman said it would boost the economy and create jobs. By the following day, shares in privately owned power company Contact Energy had fallen by more than 10 percent.


Electricity market

Electricity is traded wholesale on a spot market. The market operation is managed by several service providers under agreements with the Electricity Authority. The physical operation of the market is managed by Transpower in its role as System Operator. Generators submit offers (bids) through a Wholesale Information and Trading System (WITS). Each offer covers a future half-hour period (called a trading period) and is an offer to generate a specified quantity at that time in return for a nominated price. The WITS system platform is run by the
NZX New Zealand's Exchange (), known commonly as the NZX, is the national stock exchange for New Zealand and a publicly owned company. NZX is the parent company of Smartshares, and Wealth Technologies. On 30 August 2020, the NZX had a total of ...
. The System Operator (Transpower) uses a scheduling, pricing and dispatch (SPD) system to rank offers, submitted through WITS, in order of price, and selects the lowest-cost combination of offers (bids) to satisfy demand. The market pricing principle is known as bid-based security-constrained economic dispatch with nodal prices. The highest-priced bid offered by a generator required to meet demand for a given half-hour sets the spot price for that trading period. Electricity spot prices can vary significantly across trading periods, reflecting factors such as changing demand (e.g. lower prices in summer when demand is subdued) and supply (e.g. higher prices when hydro lakes and inflows are below average). Spot prices can also vary significantly across locations, reflecting electrical losses and constraints on the transmission system (e.g. higher prices in locations further from generating stations).


Generation

In 2020, New Zealand generated 42,858
gigawatt-hours A kilowatt-hour (unit symbol: kW⋅h or kW h; commonly written as kWh) is a Units of measurement, unit of energy: one kilowatt of power for one hour. In terms of SI derived units with special names, it equals 3.6 Joule, megajoules (MJ). Kil ...
(GWh) of electricity with hydroelectricity making up 56%. The installed generating capacity of New Zealand (all sources) as of December 2020 was 9,758 
megawatt The watt (symbol: W) is the unit of Power (physics), power or radiant flux in the International System of Units, International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantification (science), ...
s (MW), from hydroelectricity,
natural gas Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbo ...
, geothermal, wind, coal, oil, and other sources (mainly biogas, waste heat and wood).


Hydro

Hydroelectric power stations generate most of New Zealand's electricity, with 24,066 GWh generated by hydroelectricity in 2020 – 56 percent of New Zealand's electricity generated that year. The total hydroelectricity installed capacity is 5,434 MW as at the end of 2020. There are three major hydroelectric schemes in the South Island:
Waitaki Waitaki District is a territorial authority district that is located in the Canterbury and Otago regions of the South Island of New Zealand. It straddles the traditional border between the two regions, the Waitaki River, and its seat is Oamaru. ...
, Clutha and Manapouri. The Waitaki scheme has three distinct parts – the original Waitaki and Tekapo A power stations (1936 and 1951 respectively), the 1960s Lower Waitaki development consisting of Benmore and Aviemore, and the 1970–80s Upper Waitaki development of Tekapo B and Ohau A, B, and C. In total, the nine powerhouses generate approximately 7600 GWh annually, around 18% of New Zealand's electricity and more than 30% of all its hydroelectricity. Manapouri Power Station is a single
underground power station An underground power station is a type of hydroelectric power station constructed by excavating the major components (e.g. machine hall, penstocks, and tailrace) from rock, rather than the more common surface-based construction methods. One or mor ...
in Fiordland, and the largest hydroelectric station in the country. It has a maximum generating capacity of 730 MW and produces 4800 GWh annually, mainly for the Tiwai Point aluminium smelter near
Invercargill Invercargill ( , mi, Waihōpai is the southernmost and westernmost city in New Zealand, and one of the southernmost cities in the world. It is the commercial centre of the Southland region. The city lies in the heart of the wide expanse of t ...
. Both Waitaki and Manapouri are operated by Meridian Energy. There are two power stations on the Clutha River scheme operated by Contact Energy:
Clyde Dam The Clyde Dam, New Zealand's third-largest hydroelectric dam, is built on the Clutha River / Mata-Au near the town of Clyde. It is owned and operated by Contact Energy. History There was considerable controversy when the dam was planned because i ...
(464 MW, commissioned 1992) and Roxburgh Dam (320 MW, commissioned 1962). The North Island has two major schemes: Tongariro and Waikato. The Tongariro Power Scheme consists of water taken from the catchments of the Whangaehu, Rangitikei, Whanganui and Tongariro Rivers passing through two powerhouses (Tokaanu and Rangipo) before being deposited in Lake Taupo. The scheme is operated by Genesis Energy and has an installed capacity of 360 MW. The Waikato River Scheme, operated by
Mercury Energy Mercury NZ Limited is a New Zealand electricity generation and multi-product utility retailer of electricity, gas, broadband and mobile telephone services. All the company's electricity generation is renewable. In August 2021, Mercury acquired ...
, consists of nine powerhouses on the river between Lake Taupo and
Hamilton Hamilton may refer to: People * Hamilton (name), a common British surname and occasional given name, usually of Scottish origin, including a list of persons with the surname ** The Duke of Hamilton, the premier peer of Scotland ** Lord Hamilt ...
, generating 3650 GWh annually. Other smaller hydroelectricity facilities and schemes are scattered around both islands of mainland New Zealand. Hydroelectric schemes have largely shaped hinterland New Zealand. Towns including Mangakino, Turangi, Twizel and
Otematata Otematata is a town in the Waitaki District of Otago in New Zealand's South Island. It is defined as a "populated area less than a town" and the 2001 New Zealand census gave the "usually resident population count" as 243. By the 2018 census it ...
were originally founded for workers constructing hydroelectric schemes, and their families. The hydroelectric reservoirs of Lake Ruataniwha and Lake Karapiro are world-class rowing venues, with the latter having hosted the 1978 and the
2010 World Rowing Championships The 2010 World Rowing Championships were World Rowing Championships that were held from 31 October to 7 November 2010 on Lake Karapiro near Cambridge, New Zealand. The annual week-long rowing regatta was organised by FISA (the International Rowi ...
. Other schemes have shaped political New Zealand. In the 1970s, the original plans to raise Lake Manapouri for the Manapouri station were scrapped after major protests. Later in the 1980s, protests were made against the creation of
Lake Dunstan Lake Dunstan is a man-made lake and reservoir in the South Island of New Zealand. The lake was formed on the Clutha River as a result of the construction of the Clyde Dam, filling in four controlled stages beginning in April 1992 and completed ...
behind the Clyde Dam, which would flood the
Cromwell Gorge The Cromwell Gorge is a deep gorge on the Clutha River in the Otago region of New Zealand's South Island. It stretches for 20 km south of the town of Cromwell towards Alexandra. It is one of three substantial river gorges in Central Ota ...
and part of
Cromwell Oliver Cromwell (25 April 15993 September 1658) was an English politician and military officer who is widely regarded as one of the most important statesmen in English history. He came to prominence during the 1639 to 1651 Wars of the Three Ki ...
township, destroying many fruit orchards and the main street of Cromwell. However, the project was given the go ahead and Lake Dunstan was filled in 1992–93. Hydroelectricity generation has remained relatively steady since 1993 – the only major hydroelectricity projects since then was the completion of the second Manapouri tailrace tunnel in 2002, increasing the station output from 585 MW to a maximum continuous rating of 850 MW, although due to
resource consent A resource consent is the authorisation given to certain activities or uses of natural and physical resources required under the New Zealand Resource Management Act (the "RMA"). Some activities may either be specifically authorised by the RMA or ...
conditions, maximum generation is limited to 800 MW. No major new hydroelectric projects have been committed as of December 2011, but there are proposals for further developments on the Waitaki and Clutha Rivers, and on the West Coast of the South Island.


Geothermal

New Zealand lies on the
Pacific Ring of Fire The Ring of Fire (also known as the Pacific Ring of Fire, the Rim of Fire, the Girdle of Fire or the Circum-Pacific belt) is a region around much of the rim of the Pacific Ocean where many Types of volcanic eruptions, volcanic eruptions and ...
, so has favourable geology for
geothermal power Geothermal power is electrical power generated from geothermal energy. Technologies in use include dry steam power stations, flash steam power stations and binary cycle power stations. Geothermal electricity generation is currently used in 2 ...
. Geothermal fields have been located across New Zealand, but at present, most geothermal power is generated within the Taupo Volcanic Zone – an area in the North Island stretching from Mount Ruapehu in the south to
White Island White Island may refer to: Places Oceania *Whakaari / White Island, volcanic island in the Bay of Plenty, New Zealand **2019 Whakaari / White Island eruption *White Island (Otago), Dunedin, New Zealand North America *White Island, Paget, Bermuda ...
in the north. As at December 2020, the installed capacity of geothermal power was 991 MW, and in 2020, geothermal stations generated 7,610 GWh – 18% of the country's electricity generation that year. Most of New Zealand's geothermal power is generated north of Lake Taupo. Eight stations generate electricity here, including
Wairakei Power Station The Wairakei Power Station is a geothermal power station near the Wairakei Geothermal Field in New Zealand. Wairakei lies in the Taupo Volcanic Zone. History The power station was built in 1958, the first of its type (wet steam) in the world, ...
, New Zealand's oldest (1958) and largest (176 MW) geothermal power station, and the world's second large-scale geothermal power facility. Also in this area are Nga Awa Purua, which is home to the world's largest geothermal turbine at 147 MW (although the plant only generates 140 MW); and Ohaaki, which has a 105-metre tall
hyperboloid In geometry, a hyperboloid of revolution, sometimes called a circular hyperboloid, is the surface generated by rotating a hyperbola around one of its principal axes. A hyperboloid is the surface obtained from a hyperboloid of revolution by defo ...
natural draft
cooling tower A cooling tower is a device that rejects waste heat to the atmosphere through the cooling of a coolant stream, usually a water stream to a lower temperature. Cooling towers may either use the evaporation of water to remove process heat and ...
: the only one of its kind in New Zealand. A significant amount of geothermal electricity is also generated near Kawerau in the eastern Bay of Plenty, and a small amount is generated near Kaikohe in Northland. Much of New Zealand's geothermal power potential still lies untapped, with the
New Zealand Geothermal Association New is an adjective referring to something recently made, discovered, or created. New or NEW may refer to: Music * New, singer of K-pop group The Boyz Albums and EPs * ''New'' (album), by Paul McCartney, 2013 * ''New'' (EP), by Regurgitator, ...
estimating an installation capacity (using only existing technology) of around 3,600 MW.


Wind

Wind generated 5% of electricity in 2020. This was down from 7% in 2016 and 9% in 2015. As at end 2020, wind power accounts for 690 MW of installed capacity. Consents have been granted for
wind farm A wind farm or wind park, also called a wind power station or wind power plant, is a group of wind turbines in the same location used Wind power, to produce electricity. Wind farms vary in size from a small number of turbines to several hundre ...
s with a further capacity of 2,500 MW. New Zealand has abundant wind resources. The country is in the path of the Roaring Forties, strong and constant westerly winds, and the funneling effect of Cook Strait and the Manawatu Gorge increase the resource's potential. These effects make the Lower
North Island The North Island, also officially named Te Ika-a-Māui, is one of the two main islands of New Zealand, separated from the larger but much less populous South Island by the Cook Strait. The island's area is , making it the world's 14th-largest ...
the main region for wind generation. About 70 percent of the nation's current installed capacity lies within this region, with some turbines in this area having a capacity factor of over 50 percent. Electricity was first generated by wind in New Zealand in 1993, by a 225 kW demonstration turbine in the Wellington suburb of Brooklyn. The first commercial wind farm was established in 1996 – the Hau Nui Wind Farm, 22 km southeast of Martinborough had seven turbines and generated 3.85 MW. The Tararua Wind Farm was first commissioned in 1999 with 32 MW of generating capacity, gradually expanding over the next eight years to 161 MW – the largest wind farm in New Zealand. Other major wind farms include Te Apiti,
West Wind A west wind is a wind that originates in the west and blows in an eastward direction. Mythology and Literature In European tradition, it has usually been considered the mildest and most favorable of the directional winds. In Greek mythology, ...
and White Hill. Wind power in New Zealand shares the difficulties typical to other nations (uneven wind strengths, ideal locations often remote from power demand areas). New Zealand wind farms provide on average a 45% capacity factor (in other words, wind farms in New Zealand can produce more than double their average energy during periods of maximum useful wind strengths). The Tararua Wind Farm averages slightly more than this. The New Zealand Energy Efficiency and Conservation Authority figures indicate that wind power is also expected to operate at maximum capacity for around 4,000 hours a year, much more than for example the approximately 2,000 hours (Germany) to 3,000 hours (Scotland, Wales, Western Ireland) found in European countries.


Fossil-fuel thermal

Fossil fuels generated 8,154 GWh in 2020 – 18.9% of all electricity – 5,938 GWh by gas, 2,159 GWh by coal, and 57 GWh from other sources. Total combined installed capacity in 2020 was 2,334 MW. The North Island generates nearly all of New Zealand's fossil-fuelled electricity. Until the 1950s, fossil-fuelled stations were small-scale and usually fuelled by coal or coal by-products, providing electricity to cities yet to be connected to hydro schemes and to provide additional support to such schemes. Large-scale coal-fired generation began in 1958 at the 210 MW
Meremere Power Station Meremere Power Station is a former coal-fired power station on the Waikato River at Meremere, approximately south of Auckland, New Zealand. Meremere was the first major coal-fired power station in New Zealand, and was commissioned to help meet th ...
. Oil-fired stations such as Otahuhu A, Marsden A&B, and New Plymouth were commissioned in the late 1960s and early 1970s. The discovery of natural gas off the Taranaki coast, and the oil crises of the 1970s, saw oil-fired stations converted to gas or mothballed, while gas-fired stations proliferated, especially in Taranaki and Auckland, well into the 2000s. Only in recent years has coal made a comeback, as Taranaki gas has slowly depleted. Today, there are three major fossil-fuelled stations in New Zealand. Smaller gas- and coal-fired industrial generators are found across New Zealand and especially in Auckland, Waikato, Bay of Plenty, and Taranaki. Genesis Energy's
Huntly Power Station The Huntly Power Station is the largest thermal power station in New Zealand and is located in the town of Huntly in the Waikato. It is operated by Genesis Energy Limited, a publicly listed company (currently 51% owned by the NZ Government). Th ...
in northern Waikato is New Zealand's largest power station – with 1000 MW of coal- and gas-fired generators and 435 MW of gas-only generators, it supplies around 17% of the country's electricity. There is a gas-fired power station in Taranaki at Stratford (585 MW). Whirinaki is a 155 MW
diesel Diesel may refer to: * Diesel engine, an internal combustion engine where ignition is caused by compression * Diesel fuel, a liquid fuel used in diesel engines * Diesel locomotive, a railway locomotive in which the prime mover is a diesel engin ...
-fired station north of
Napier Napier may refer to: People * Napier (surname), including a list of people with that name * Napier baronets, five baronetcies and lists of the title holders Given name * Napier Shaw (1854–1945), British meteorologist * Napier Waller (1893–19 ...
, providing backup generation for periods when generation is not otherwise available, such as when plants break down, or during dry seasons where there is limited water for hydroelectricity generation. As of 2021 none of the power generators appear to be committed to the construction of any new fossil-fuelled power stations. There is only one proposed thermal station with resource consent:
Todd Energy The Todd Corporation is a large private New Zealand company with a value of $4.3 billion, owned and controlled by the Todd family and headquartered in Wellington, New Zealand. The corporation is currently led by chairman of the board, Henry Tait ...
's 380MW Waikato Power Plant.


Other sources


Solar

As at the end of May 2021, New Zealand had 32,650 grid-connected photovoltaic (PV) installations producing 159MW, of which 57MW were installed in the preceding 24 months.


Marine

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
has large
ocean energy Marine energy or marine power (also sometimes referred to as ocean energy, ocean power, or marine and hydrokinetic energy) refers to the energy carried by ocean waves, tides, salinity, and ocean thermal energy, ocean temperature differences. The ...
resources but does not yet generate any power from them.
TVNZ , type = Crown entity , industry = Broadcast television , num_locations = New Zealand , location = Auckland, New Zealand , area_served = Nationally (New Zealand) and some Pacific Island nations such as the Cook Islands, Fiji, and the So ...
reported in 2007 that over 20
wave In physics, mathematics, and related fields, a wave is a propagating dynamic disturbance (change from equilibrium) of one or more quantities. Waves can be periodic, in which case those quantities oscillate repeatedly about an equilibrium (res ...
and
tidal power Tidal power or tidal energy is harnessed by converting energy from tides into useful forms of power, mainly electricity using various methods. Although not yet widely used, tidal energy has the potential for future electricity generation. Ti ...
projects are currently under development. However, not a lot of public information is available about these projects. The
Aotearoa Wave and Tidal Energy Association The Aotearoa Wave and Tidal Energy Association (AWATEA) is a New Zealand organisation established in 2006 to promote renewable energy from marine sources. This includes energy from Tidal power, tides, wave power, waves and Marine current power, oc ...
was established in 2006 to "promote the uptake of marine energy in New Zealand". According to their latest newsletter, they have 59 members. However the association doesn't list these members or provide any details of projects. From 2008 to 2011, the government Energy Efficiency and Conservation Authority allocated $2 million each year from a Marine Energy Deployment Fund, set up to encourage the utilisation of this resource. The greater Cook Strait and Kaipara Harbour seem to offer the most promising sites for using underwater turbines. Two resource consents have been granted for pilot projects in Cook Strait itself and in the
Tory Channel Tory Channel / Kura Te Au is one of the drowned valleys that form the Marlborough Sounds in New Zealand. Inter-island ferries normally use it as the principal channel between Cook Strait and the Marlborough Sounds. Tory Channel / Kura Te Au lies ...
, and consent has been granted for up to 200 tidal turbines at the
Kaipara Tidal Power Station The Kaipara tidal power station is a proposed tidal power project to be located in the Kaipara Harbour. The project is being developed by Crest Energy, with an ultimate size of 200MW at a cost of $600 million. Crest plans to place the turbines a ...
. Other potential locations include the
Manukau Manukau (), or Manukau Central, is a suburb of South Auckland, New Zealand, centred on the Manukau City Centre business district. It is located 23 kilometres south of the Auckland Central Business District, west of the Southern Motorway, so ...
and Hokianga Harbours, and
Te Aumiti / French Pass French Pass (; officially Te Aumiti / French Pass) is a narrow and treacherous stretch of water that separates D'Urville Island, at the north end of the South Island of New Zealand, from the mainland coast. At one end is Tasman Bay, and at the ot ...
. The harbours produce currents up to 6
knots A knot is a fastening in rope or interwoven lines. Knot may also refer to: Places * Knot, Nancowry, a village in India Archaeology * Knot of Isis (tyet), symbol of welfare/life. * Minoan snake goddess figurines#Sacral knot Arts, entertainme ...
with tidal flows up to 100,000 cubic metres a second. These tidal volumes are 12 times greater than the flows in the largest New Zealand rivers.


Nuclear

Although New Zealand has nuclear-free legislation, it covers only nuclear-propelled ships, nuclear explosive devices and radioactive waste. The legislation does not prohibit the building and operation of a nuclear power station. The only significant proposal for a nuclear power station in New Zealand was the Oyster Point Power Station, on the Kaipara Harbour near Kaukapakapa north of Auckland. Between 1968 and 1972, there were plans to develop four 250 MW reactors at the site. By 1972, the plans were dropped as the discovery of the
Maui gas field The Maui natural gas field is the largest gas, natural gas condensate and oil field in New Zealand, producing nearly three-quarters of the country's hydrocarbons, as well as providing energy for electricity generation. It is located in the Tasman ...
meant there was no immediate need to embark on a nuclear programme. The Royal Commission on Nuclear Power Generation in New Zealand was set up in 1976 and reported back to the Government in April 1978. The commission concluded there was no immediate need for nuclear power in New Zealand, but may be economically possible in the early 21st century.


Transmission

New Zealand's national electricity transmission grid connects its generating facilities to its demand centres, which are often more than from each other. The national grid is owned, operated and maintained by
state-owned enterprise A state-owned enterprise (SOE) is a Government, government entity which is established or nationalised by the ''national government'' or ''provincial government'' by an executive order or an act of legislation in order to earn Profit (econom ...
Transpower New Zealand Transpower New Zealand Limited (TPNZ) is the state-owned enterprise responsible for electric power transmission in New Zealand. It performs two major functions in the New Zealand electricity market. As the owner of the National Grid it provi ...
. The grid contains route-length of high-voltage lines and 178 substations. The first major transmission lines were built in 1913–14, connecting the Horahora hydro station to
Waikino Waikino is a small settlement at the eastern end of a gorge in the North Island of New Zealand alongside the Ohinemuri River, between Waihi and the Karangahake Gorge. The Waikino district lies at the base of the ecologically sensitive Coromandel ...
, and Coleridge hydro station with Addington in Christchurch. The interwar years saw the first major construction of a national network of 110 kV lines connecting towns and cities to hydroelectric schemes. By 1940, the transmission network stretched from Whangarei to Wellington in the North Island, and Christchurch to Greymouth and Invercargill in the South Island. Nelson and Marlborough were the last major regions to join the national grid in 1955. The 220 kV network began in the early 1950s, connecting the Waikato River dams to Auckland and Wellington, and Roxburgh Dam to Christchurch. The two islands were joined by the HVDC Inter-Island link in 1965. The first 400 kV transmission line was completed between Whakamaru Dam on the Waikato River and Brownhill substation east of Auckland in 2012, but presently is operated at 220 kV.


Existing grid

The backbone of the grid in each island is the network of 220 kV transmission lines. These lines connect the larger cities and power users with the major power stations. Lower capacity 110 kV and 66 kV transmission lines connect smaller towns and cities and smaller power stations, and are connected to the 220 kV core grid through points of interconnection at major transmission substations. These stations include Otahuhu and Penrose in Auckland, Whakamaru,
Wairakei Wairakei is a small settlement, and geothermal area a few kilometres north of Taupō, in the centre of the North Island of New Zealand, on the Waikato River. It is part of the Taupō Volcanic Zone and features several natural geysers, hot pool ...
and
Bunnythorpe Bunnythorpe is a village in the Manawatū-Whanganui region of New Zealand's North Island, north of the region's major city, Palmerston North. Dairy farms predominate the surrounding area but the community facilities include Bunnythorpe School, w ...
in the central North Island,
Haywards Haywards is a small hillside suburb in the Hutt Valley near Wellington, New Zealand. It is notable for its large electrical substation, which is the main switching point for the Wellington region, and the home of the North Island converter stat ...
in Wellington,
Islington Islington () is a district in the north of Greater London, England, and part of the London Borough of Islington. It is a mainly residential district of Inner London, extending from Islington's High Street to Highbury Fields, encompassing the ar ...
and
Bromley Bromley is a large town in Greater London, England, within the London Borough of Bromley. It is south-east of Charing Cross, and had an estimated population of 87,889 as of 2011. Originally part of Kent, Bromley became a market town, char ...
in Christchurch, and Twizel and Benmore in the Waitaki Valley. Investments in new transmission are regulated by the Commerce Commission. In a news release in January 2012, the Commerce Commission reported that Transpower was planning to invest $5 billion over the next 10 years in upgrades of critical infrastructure. Since 2006, Transpower has spent nearly $2 billion reinforcing the supply into and around Auckland. A 400 kV-capable transmission line was completed in 2012, linking Whakamaru to Brownhill substation in Whitford, east of Auckland, with 220 kV cables linking Brownhill to
Pakuranga Pakuranga is an eastern suburb of Auckland, in northern New Zealand. Pakuranga covers a series of low ridges and previously swampy flats, now drained, that lie between the Pakuranga Creek and Tamaki River, two estuarial arms of the Hauraki Gul ...
. In 2014, a new 220 kV cable was commissioned between Pakuranga and Albany (via Penrose, Hobson Street and Wairau Road), forming a second high-voltage route between northern and southern Auckland.


HVDC Inter-Island

The HVDC Inter-Island scheme is New Zealand's only
high voltage direct current A high-voltage direct current (HVDC) electric power transmission system (also called a power superhighway or an electrical superhighway) uses direct current (DC) for electric power transmission, in contrast with the more common alternating curren ...
(HVDC) system, and links the North and South Island grids together. The link connects the South Island converter station at the
Benmore Dam Benmore Dam is the largest dam within the Waitaki power scheme, located in the Canterbury Region of New Zealand's South Island. There are eight other power stations in the Waitaki Power Scheme. The dam is the largest earth-fill (zoned embankme ...
in southern
Canterbury Canterbury (, ) is a City status in the United Kingdom, cathedral city and UNESCO World Heritage Site, situated in the heart of the City of Canterbury local government district of Kent, England. It lies on the River Stour, Kent, River Stour. ...
with the North Island converter station at
Haywards Haywards is a small hillside suburb in the Hutt Valley near Wellington, New Zealand. It is notable for its large electrical substation, which is the main switching point for the Wellington region, and the home of the North Island converter stat ...
substation in the Hutt Valley via 572 km of overhead bipolar HVDC lines and 40 km submarine cables across Cook Strait. The HVDC link was commissioned in 1965 as a ±250 kV, 600 MW bipolar HVDC scheme using mercury-arc valve converters, and was originally designed to transfer surplus South Island hydroelectric power northwards to the more populous North Island. In 1976, the control system of the original scheme was modified to allow power to be sent in the reverse direction, from Haywards to Benmore, allowing the South Island to access the North Island's thermal generation during dry periods. In 1992, the original mercury-arc equipment was paralleled to create a single pole (Pole 1), and a new
thyristor A thyristor () is a solid-state semiconductor device with four layers of alternating P- and N-type materials used for high-power applications. It acts exclusively as a bistable switch (or a latch), conducting when the gate receives a current ...
-based pole (Pole 2) was commissioned alongside it. The transmission lines and submarine cables were also upgraded to double the link's maximum capacity to 1240 MW. The mercury-arc valve converter equipment was partially decommissioned in 2007, and fully decommissioned in August 2012. New thyristor converter stations (known as Pole 3) were commissioned on 29 May 2013, to replace the mercury arc converters. Further work to Pole 2 brought the link's capacity to 1200 MW by the end of the year.


Distribution

Electricity from Transpower's national grid is distributed to local lines companies and large industrial users via 180 grid exit points (GXPs) at 147 locations. Large industrial companies, such as New Zealand Steel at Glenbrook, the Tasman Pulp and Paper Mill at Kawerau, the Tiwai Point Aluminium Smelter near Bluff, and KiwiRail for its 25 kV AC electrification in Auckland and the central North Island, draw directly from Transpower substations and not the local lines companies' local grids. Distribution of electricity to local consumers is managed by of one of 29 electricity distribution businesses (EDBs). Each EDB serves specific geographic regions. The 29 electricity distribution businesses differ widely in scale, ranging from Buller Electricity with 4,683 customer connections and a regulatory asset base of $30million, through to Vector with 573,860 customer connections and a regulatory asset base of $3,565million. In most areas, the local lines company operates a subtransmission network, connecting the transmission grid exit point to zone substations. At the zone substation (or at the GXP if there is no subtransmission network), the voltage is stepped down to distribution voltage. Three-phase distribution is available in all urban and most rural areas. Single- or two-phase distribution utilising only two phases or
single wire earth return Single-wire earth return (SWER) or single-wire ground return is a single-wire transmission line which supplies single-phase electric power from an electrical grid to remote areas at lowest cost. Its distinguishing feature is that the earth (or ...
systems are used in outlying and remote rural areas with light loads. Local pole-mounted or ground-mounted distribution transformers step-down the electricity from distribution voltage to the New Zealand
mains voltage Mains electricity or utility power, power grid, domestic power, and wall power, or in some parts of Canada as hydro, is a general-purpose alternating-current (AC) electric power supply. It is the form of electrical power that is delivered to ...
of 230/400 volts (phase-to-earth/phase-to-phase). Subtransmission is typically at 33 kV, 50 kV, 66 kV or 110 kV, although parts of Auckland isthmus use 22 kV subtransmission. Distribution is typically at 11 kV, although some rural areas and high-density urban areas use 22 kV distribution, and some urban areas (e.g. Dunedin) use 6.6 kV distribution. As of 31 March 2020, the 29 EDBs combined had of subtransmission lines and cables and of distribution and low-voltage lines and cables. There were 1,282 zone substation transformers, 191,501 distribution transformers, and 1,359,439 power poles.


Regulation of distribution businesses

Electricity distribution businesses are
natural monopolies A natural monopoly is a monopoly in an industry in which high infrastructural costs and other barriers to entry relative to the size of the market give the largest supplier in an industry, often the first supplier in a market, an overwhelming adv ...
, and are subject to regulation under Part 4 of the
Commerce Act 1986 The Commerce Act 1986 is a statute of New Zealand. It prohibits conduct that restricts competition and purchase of shares or assets where that would lessen competition in a market. As well as generally governing markets, the Act gives the Comm ...
. There are two main regulatory mechanisms in place; information disclosure regulation and price-quality regulation.


Information disclosure regulation

Each year, the Commerce Commission requires EDBs to publish financial information including financial statements, future expenditure forecasts and pricing, and performance information including outages and interruptions. The Commerce Commission publishes analysis of the information disclosures to assist industry analysts and members of the public to understand and compare the performance of EDBs.


Price-quality regulation

Price-quality regulations set the maximum revenue or maximum average price an EDB can charge consumers as well as the quality standards they must meet, usually measured in the frequency and duration of power outages. EDBs who fail to meet these standards may be give a public warning, and repeat failures may result in prosecution. In March 2020, Aurora Energy was fined nearly $5 million after four consecutive years where it failed to meet the required quality standards, largely resulting from historic under-investment in network renewal and maintenance. The following EDBs are subject to price-quality regulation for the 2020–2025 period: *
Alpine Energy Alpine Energy Limited is an electricity distribution business based in Timaru, New Zealand. The company own and operates the electricity distribution network in South Canterbury. The company's distribution network consists of of lines, supplyi ...
* Aurora Energy * Centralines * Eastland Networks *
Electricity Ashburton Electricity Ashburton Limited, trading as EA Networks is a co-operatively-owned electricity distribution company, based in Ashburton, New Zealand. The company was formed as Electricity Ashburton in 1995 after a reorganisation of the Ashburton ...
* Electricity Invercargill * Horizon Energy * The Lines Company * Network Tasman * Nelson Electricity * Orion * OtagoNet Joint Venture *
Powerco Powerco is the second-largest natural gas, gas and largest electricity distributor in New Zealand. It is one of only two companies to distribute both electricity and natural gas through their network (the other being Vector Limited). Its network ...
*
Top Energy Top Energy Limited is an electricity distribution and generation company based in Kerikeri, New Zealand. It owns and manages the electricity lines network in the Far North District of New Zealand, including Kaitaia, Kerikeri and Kaikohe. The serv ...
*
Unison Networks Unison Networks Limited (Unison) is an electricity distribution and fibre optic network company, based in Hastings, New Zealand. Unison owns and manages the electricity lines network and the fibre optic network in the Hawke's Bay, Rotorua and ...
* Vector *
Wellington Electricity Wellington Electricity, registered as Wellington Electricity Lines Limited, is an electricity distribution company, based in Wellington, New Zealand. Wellington Electricity supplies electricity to approximately 400,000 consumers through over 1 ...
The following EDBs meet criteria for "consumer-owned" businesses and are exempt from price-quality regulation: * Buller Electricity * Counties Power *
Electra Electra (; grc, Ήλέκτρα) is one of the most popular mythological characters in tragedies.Evans (1970), p. 79 She is the main character in two Greek tragedies, '' Electra'' by Sophocles and '' Electra'' by Euripides. She is also the centra ...
*
Mainpower MainPower New Zealand Limited is an electricity distribution company, based in Rangiora, New Zealand, responsible for electricity distribution to nearly 42,000 customers in the Canterbury region north of the Waimakariri River. MainPower was forme ...
* Marlborough Lines * Network Waitaki * Northpower * Scanpower *
The Power Company An electric utility is a company in the electric power industry (often a public utility) that engages in electricity generation and distribution of electricity for sale generally in a regulated market. The electrical utility industry is a major pr ...
* Waipa Networks *
WEL Networks WEL Networks Limited is an electricity distribution company, serving the northern and central Waikato region of New Zealand. WEL is the fifth largest electricity distribution companies in New Zealand, with over 80,000 connections and 5,226  ...
* Westpower


Low voltage supply

Distribution companies provide supply at a nominal voltage of 230volts ± 6% for
single-phase In electrical engineering, single-phase electric power (abbreviated 1φ) is the distribution of alternating current electric power using a system in which all the voltages of the supply vary in unison. Single-phase distribution is used when load ...
and 400volts ± 6% for
three-phase Three-phase electric power (abbreviated 3φ) is a common type of alternating current used in electricity generation, Electric power transmission, transmission, and Electric power distribution, distribution. It is a type of polyphase system empl ...
supply, except for momentary fluctuations, in accordance with the Electricity (Safety) Regulations 2010. AC power plugs (male) and sockets (female) comply with the harmonised Australian and New Zealand standard
AS/NZS 3112 AS/NZS 3112 is the harmonised Australian and New Zealand standard for AC power plugs (male) and sockets (female). The standard is used in Australia, Argentina, New Zealand, Fiji, Tonga, Solomon Islands, Papua New Guinea and several other Pacifi ...
that is also used in
Fiji Fiji ( , ,; fj, Viti, ; Fiji Hindi: फ़िजी, ''Fijī''), officially the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean. It lies about north-northeast of New Zealand. Fiji consists ...
,
Tonga Tonga (, ; ), officially the Kingdom of Tonga ( to, Puleʻanga Fakatuʻi ʻo Tonga), is a Polynesian country and archipelago. The country has 171 islands – of which 45 are inhabited. Its total surface area is about , scattered over in ...
,
Solomon Islands Solomon Islands is an island country consisting of six major islands and over 900 smaller islands in Oceania, to the east of Papua New Guinea and north-west of Vanuatu. It has a land area of , and a population of approx. 700,000. Its capita ...
,
Papua New Guinea Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...
and several other Pacific island countries. New Zealand uses a variation on the TN-C-S earthing system known as ''multiple earthed neutral'' (MEN). Each consumer premises is required to have its own earth electrode, which connects to the protective earth busbar in the main distribution board. The neutral wire is connected to earth at the distribution transformer, and within each consumer's main distribution board by an electrical connector between the neutral busbar and the protective earth busbar known as the MEN link.


Consumption

In 2019, New Zealand consumed 39,950 GWh of electricity. Industry consumed 38% of that figure, agriculture 6%, commerce 24%, and homes 31%. As at 31 May 2021, there were 2,210,593 connections to the national electricity network. The highest peak demand recorded in New Zealand was 7,100 MW, recorded between 18:00 and 18:30 on 9 August 2021. The previous record was 6,924 MW, recorded between 18:00 and 18:30 on 29 June 2021. New Zealand's largest single electricity user is the Tiwai Point Aluminium Smelter in Southland, which can demand up to 640 megawatts of power, and annually consumes around 5400 GWh. The smelter effectively has the
Manapouri power station Manapōuri Power Station is an underground hydroelectric power station on the western arm of Lake Manapouri in Fiordland National Park, in the South Island of New Zealand. At 854 MW installed capacity (although limited to 800 MW due to ...
as a dedicated power generator to supply it. Other large industrial users include the Tasman pulp and paper mill at Kawerau (175 MW demand), and New Zealand Steel's Glenbrook mill (116 MW demand). The other major consumers are the cities, with
Auckland Auckland (pronounced ) ( mi, Tāmaki Makaurau) is a large metropolitan city in the North Island of New Zealand. The List of New Zealand urban areas by population, most populous urban area in the country and the List of cities in Oceania by po ...
, the nation's largest city, demanding up to 1722 MW and consuming 8679 GWh in 2010–11. Wellington, Christchurch, Hamilton and Dunedin are also major consumers, with other large demand centres including Whangarei-Marsden Point, Tauranga, New Plymouth, Napier-Hastings, Palmerston North, Nelson, Ashburton, Timaru-Temuka, and Invercargill.


Retail and residential supply

The total residential electricity consumption in 2020 was around 12.9 TWh. Average annual household consumption shows a generally downward trend over the period from 2006 to 2021. Average annual household expenditure on electricity has been relatively stable in real terms, increasing by approximately 11% over the same period. In 2021, the average annual residential consumption was 7,223kWh per household, varying from 5,938kWh per household on the
West Coast West Coast or west coast may refer to: Geography Australia * Western Australia *Regions of South Australia#Weather forecasting, West Coast of South Australia * West Coast, Tasmania **West Coast Range, mountain range in the region Canada * Britis ...
to 8,467kWh per household in Southland. The average annual household expenditure in 2021 was $2,121. Generation represents approximately one third of the cost of retail electricity, with the combined cost of transmission and distribution making up just under another third. The balance includes the retailing margin, levies and
GST GST may refer to: Taxes * General sales tax * Goods and Services Tax, the name for the value-added tax in several jurisdictions: ** Goods and services tax (Australia) ** Goods and Services Tax (Canada) ** Goods and Services Tax (Hong Kong) **G ...
. Most retail customers have term contracts with their electricity retailer, but some are on pre-pay arrangements. Customers may choose pre-pay to help them manage expenditure, but others may be forced onto pre-pay because they have been deemed to be a credit risk or have a history of disconnection because of unpaid bills. The costs of electricity on pre-pay are typically more than on term contract. The higher costs of pre-pay electricity can be a significant concern because research in New Zealand and in other countries indicates that households on pre-pay are more likely to be unable to afford to adequately heat their homes.


Customer switching

Electricity consumers connected to the grid have a choice of retail supplier. As at 31 July 2021, there were 40 electricity retailers registered with the Electricity Authority, although only 13 retailers had more than 10,000 customers. The top five retailers by number of individual consumer connections were Contact Energy, Genesis Energy, Mercury Energy, Trustpower, and Meridian Energy. These top five retailers are also generation companies. The Electricity Authority funds a price-comparison service managed by Consumer New Zealand, to assist residential consumers to compare pricing offered by different retailers, and evaluate the benefits of switching suppliers. The rate of customers switching suppliers has increased significantly over the past two decades, from 11,266 per month in January 2004 to 38,273 per month in May 2021.


Load control

Load control, especially of domestic electric water heaters, has been and remains a major tool for electricity distribution businesses. Consumers are offered a lower rate, either overall or only for controlled load, in exchange for allowing the EDB to switch off the controlled load at peak times. Switching off and on the controlled load is normally achieved by ripple control, where an audio-frequency signal is sent by the EDB along the power lines to operate the relay at each consumers' premises. In 2018, it was estimated that up to 986MW of load could be controlled.


Smart meters

Smart meters A smart meter is an Electronics, electronic device that records information such as consumption of electric energy, voltage levels, current, and power factor. Smart meters Telemetering, communicate the information to the consumer for greater c ...
have been widely deployed in New Zealand to replace older generation domestic electricity meters. By 2016, over 1.5 million smart meters had been installed, representing 70% of homes. At the early stages of the installation of smart meters in 2009, the
Parliamentary Commissioner for the Environment __NOTOC__ The Parliamentary Commissioner for the Environment (''Te Kaitiaki Taiao a Te Whare Pāremata'' in Māori) is an independent Officer of the New Zealand Parliament appointed by the Governor-General on the recommendation of the House of R ...
(PCE) criticised the roll-out on the grounds that the capabilities of the metering systems being deployed were too limited, and would not sufficiently enable future benefits for the consumers and the environment. In an update report in 2013, the PCE stated: Most smart meters have been installed by electricity retailers. Retail services that have become available following the deployment of smart meters including time-of-use pricing. Some retailers offer a tariff that follows the spot price in the wholesale electricity market, and other offerings include a free ‘hour of power’ and a web-based prepay service.


Outages

As part of their information disclosure regulations, Transpower and all 29 EDBs are required to report the duration, frequency, and causes of power outages. The duration and frequency of outages are normally expressed in
SAIDI A Ṣa‘īdī (, Coptic: ⲣⲉⲙⲣⲏⲥ ''Remris'') is a person from Upper Egypt (, Coptic: ⲙⲁⲣⲏⲥ ''Maris''). Etymology The word literally means "from Ṣa‘īd" (i.e. Upper Egypt), and can also refer to a form of music orig ...
(system average interruption duration index) and SAIFI (system average interruption frequency index). In the year to 31 March 2020, the 29 EDBs reported an unplanned-outage SAIDI of 130.35 minutes and SAIFI of 1.76, and a planned-outage SAIDI of 78.85 minutes and a SAIFI of 0.37. This is equivalent to the average consumer having an unplanned power outage lasting one-and-a-quarter hours every seven months, and a planned maintenance outage lasting just over 3.5 hours every 32 to 33 months. Major power outages include: *On the evening of 1 September 1928, a fire broke out at
Horahora Power Station Horahora Power Station was an early hydroelectric power station on the Waikato River in New Zealand. It was the country’s first large-scale power station, completed in 1913. Initially built to service a gold mine, the power station was expande ...
cutting supply to the entire Auckland, Waikato and Bay of Plenty regions. Electricity was restored to most areas within four hours using backup generators, but it took until the following morning to restore electricity to Rotorua and eastern Bay of Plenty. *The
1998 Auckland power crisis The 1998 Auckland power crisis was a five-week-long power outage affecting the central city of Auckland, New Zealand from 19 February to 27 March 1998. A 1998 ministerial inquiry criticised both the Auckland Electric Power Board and its privatise ...
was a major failure of electricity distribution to the Auckland central business district. Two 40-year-old cables connecting Penrose and Auckland's central business district failed in January to February 1998 during unseasonably hot weather, causing strain on the two newer remaining cables, which subsequently failed on 20 February 1998 and plunged central Auckland into darkness. The failure cost businesses NZ$300 million, and resulted in central Auckland being without electricity for 66 days until an emergency overhead line could reconnect the city – the longest peacetime blackout in history. * In June 2006, the seven-hour
2006 Auckland Blackout The 2006 Auckland Blackout was a major electrical Power blackout, blackout in Auckland, the largest city in New Zealand, on 12 June 2006. It started at 08:30 local time, with most areas of Auckland regaining power by 14:45 local time. It affected ...
occurred when a corroded shackle at Otahuhu broke in strong winds and subsequently blacked out much of inner Auckland. * In October 2009, a three-hour blackout of northern Auckland and Northland occurred after a shipping container forklift accidentally hit the only major line supplying the region. *On 12 November 2013, a commissioning test for the upgraded HVDC Inter-Island's control systems encountered a software bug, tripping the Benmore filter banks and causing the HVDC link, at the time transmitting 1000 MW northbound, to automatically roll back to 140 MW northbound in response. This in turn activated automatic underfrequency load shedding (AUFLS) systems in the North Island, cutting off over 300,000 customers to avoid a cascading failure. Power was restored to most areas within two hours. * On Sunday 5 October 2014, a fire broke out at Transpower's Penrose substation. Major outages were experienced across central Auckland suburbs. The fire started in a cable joint in a medium voltage power cable. Over 75,000 businesses and households were affected. Power was fully restored by the afternoon of Tuesday 7 October. *On 8 December 2016, the insulators on three towers of the
Maungatapere Maungatapere is a settlement in Northland, New Zealand. State Highway 14 runs through it. Whangārei is 11 km to the east, and Tangiteroria is 18 km to the south west. The settlement takes its name from a rounded volcanic peak of the ...
to Kaikohe transmission line were shot out, cutting power to the entire
Far North district The Far North District is the northernmost territorial authority district of New Zealand, consisting of the northern part of the Northland Peninsula in the North Island. It stretches from North Cape and Cape Reinga / Te Rerenga Wairua in the ...
for 12 hours. A 46-year-old man was subsequently arrested and charged with intentional damage and unlawfully possessing a firearm; he pleaded guilty and was sentenced to 23 months in prison. *On the evening of 9 August 2021, a polar storm brought low temperatures across New Zealand and caused national electricity use to spike to 7,100 MW between 18:00 and 18:30. The Taranaki combined cycle gas turbine and
Kawerau Power Station The Kawerau Power Station is a 100-megawatt geothermal power plant located just outside the town of Kawerau in the Bay of Plenty Region of New Zealand. The power station is situated within the Kawerau geothermal field, which is part of the Taupo ...
were out of service, and only two of the three coal-fired units at Huntly were operating. An intake blockage at Tokaanu hydroelectric power station and a drop in wind across the country reducing wind generation resulted in insufficient generation and system operator Transpower declaring a grid emergency. Transpower advised EDBs to reduce demand, but miscalculated the per-EDB demand limits causing
WEL Networks WEL Networks Limited is an electricity distribution company, serving the northern and central Waikato region of New Zealand. WEL is the fifth largest electricity distribution companies in New Zealand, with over 80,000 connections and 5,226  ...
and
Unison Networks Unison Networks Limited (Unison) is an electricity distribution and fibre optic network company, based in Hastings, New Zealand. Unison owns and manages the electricity lines network and the fibre optic network in the Hawke's Bay, Rotorua and ...
to implement widespread rolling blackouts to comply.


Isolated areas

New Zealand's national electricity network covers the majority of both the North and South Islands. There are also a number of offshore islands which are connected to the national grid. Waiheke Island, New Zealand's most populous offshore island, is supplied by submarine cables from
Maraetai Maraetai is a coastal town and the easternmost suburb of greater Auckland in New Zealand. The closest town, Beachlands, lies approximately 4 km to the west. Its name is Māori meaning "meeting place by the sea". Maraetai was the origina ...
.
Arapaoa Island Arapaoa Island, formerly known as Arapawa Island, is an island located in the Marlborough Sounds, at the north east tip of the South Island of New Zealand. The island has a land area of . Queen Charlotte Sound / Tōtaranui defines its western sid ...
and
d'Urville Island D'Urville Island (), Māori language, Māori name ' ('red heavens look to the south'), is an island in the Marlborough Sounds along the northern coast of the South Island of New Zealand. It was named after the France, French List of explorers, ...
, both in the Marlborough Sounds, are supplied via overhead spans across
Tory Channel Tory Channel / Kura Te Au is one of the drowned valleys that form the Marlborough Sounds in New Zealand. Inter-island ferries normally use it as the principal channel between Cook Strait and the Marlborough Sounds. Tory Channel / Kura Te Au lies ...
and French Pass respectively. However, many offshore islands and some parts of the South Island are not connected to the national grid and operate independent generation systems, mainly due to the difficulty of building lines from other areas. Diesel-fuelled generation using internal combustion engines is a common solution. Diesel fuel suitable for generators is readily available across the country at fuel stations – diesel is not taxed at the pump in New Zealand, and instead diesel-powered vehicles pay Road User Charges based on their gross tonnage and distance travelled. Isolated areas with independent generation include: * Great Barrier Island has the largest population in New Zealand without a reticulated electricity supply. Generation is from individual schemes for households or groups of households and is a combination of renewable and non-renewable energy. * Haast. The area around Haast and extending south to Jackson Bay is not connected to the rest of New Zealand. It operates from a hydroelectric scheme on the Turnbull River with diesel backup. *
Milford Sound Milford Sound / Piopiotahi is a fiord in the south west of New Zealand's South Island within Fiordland National Park, Piopiotahi (Milford Sound) Marine Reserve, and the Te Wahipounamu World Heritage site. It has been judged the world's top tra ...
. Electricity is generated via a small hydroelectric scheme operating off Bowen Falls with a diesel backup. * Deep Cove,
Doubtful Sound Doubtful Sound / Patea is a fiord in Fiordland, in the far south west of New Zealand. It is located in the same region as the smaller but more famous and accessible Milford Sound / Piopiotahi. It took second place after Milford Sound as New Zea ...
. The small community at Deep Cove at the head of Doubtful Sound operates off a hydro scheme, although during the construction of the second Manapouri Tailrace Tunnel a high voltage cable was installed connecting this tiny settlement with the Manapouri Power Station. * Stewart Island / Rakiura. This island's power supply for a population of 300/400 people is entirely diesel generated. Renewable energy sources are limited, but they are being actively investigated in order to increase the sustainability of the island's power supply, and reduce the cost. *
Chatham Islands The Chatham Islands ( ) (Moriori: ''Rēkohu'', 'Misty Sun'; mi, Wharekauri) are an archipelago in the Pacific Ocean about east of New Zealand's South Island. They are administered as part of New Zealand. The archipelago consists of about te ...
. Power on Chatham Island is provided by two 200 kW wind turbines that provide most of the power on the island while diesel generators provide the rest, with fuel brought from the mainland. Many other schemes exist on offshore islands that have permanent or temporary habitation, mostly generators or small renewable systems. An example is the ranger / research station on Little Barrier Island, where twenty 175 watt photovoltaic panels provide the mainstay for local needs, with a diesel generator for backup.


See also

*
List of power stations in New Zealand This is a list of power stations in New Zealand. The list is not exhaustive – only power stations over 0.5 MW and significant power stations below 0.5 MW are listed. Power plants in New Zealand have different generating roles ...


References


Sources

* *


External links


Energy and Resources
(New Zealand Government, portfolio website)
Electricity Networks Association
represents the network companies (line companies) * Nuclear power generation in New Zealand : report of the Royal Commission of Inquiry (1978)
Live carbon emissions from electricity generation
electricityMap Live built by Tomorrow {{DEFAULTSORT:Electricity Sector in New Zealand