Wind Energy in New Zealand

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Te Apiti Wind Farm. Manawatu District, New Zealand [7]


Contents

The role of wind energy in New Zealand and its capacity for electricity generation

The percentage of total renewable energy generation for New Zealand from various renewable energy sources 2011 [3]


Wind energy generation is growing source of renewable energy being utilised in New Zealand and internationally. Wind energy supplies 2-4% of annual renewable electricity generation; the equivalent of what approximately 180,000 homes use per year in New Zealand [1]. Presently in New Zealand, renewable energy sources account for 75% of electricity generated [2].

New Zealand’s energy demand has experienced steady growth and is expected to continue growing as national economic growth continues [4]. In October 2007, the government adopted the use of a New Zealand Energy Strategy, which specifies that New Zealand must respond to the risks of climate change by reducing greenhouse gas emissions caused by the growing production and use of energy. It also specifies that “clean, secure, affordable energy” must be utilised while treating the environment responsibly .

The New Zealand Energy Strategy 2011-2021 and the New Zealand Energy Efficiency and Conservation Strategy 2011-2016 specifically acknowledge that renewable energy is an important part of the solution to reduce New Zealand’s total greenhouse gas emissions. It is aimed that New Zealand will have 90% renewable electricity generation by 2025 [6]. New Zealand has access to a variety of renewable energy sources (e.g. wind, hydro, geothermal and solar sources), making this goal seem attainable.

With the decline in gas supply from the Maui gas field and the seasonal and annual variation experienced by hydro power, developers are continually exploring sites to construct new wind farms throughout New Zealand [6]. Out of all sources of renewable energy, wind has the greatest potential for New Zealand. Technological developments and expertise have helped to emphasize that wind is now an economical way to generate electricity, while contributing to the goal of reducing greenhouse gas emissions such as CO2. In theory, wind turbines could be installed that would be technically able to meet all growth in electricity demand in the near future.

History of wind energy in New Zealand

The increase in wind-generated electricity in New Zealand (1991-2007)


The first modern wind turbine in New Zealand was constructed at Brooklyn in Wellington in 1993, utilising one single 0.225MW turbine owned by Meridian Energy. The turbine was built to research how wind turbines would perform in New Zealand conditions and how they compared to other forms of renewable electricity generation [7]. Since then, just over 170MW of wind power capacity has been installed, a large amount of this in the Manawatu and Wairarapa regions [8]; perfect locations for wind power generation because wind currents are accelerated through Cook Strait and over the Rimutaka Mountain Range nearby [9].

New Zealand’s first commercial wind farm was constructed in 1996 in the Wairarapa. The Hai Nui Wind Farm (owned by Genesis Energy) consists of 15 turbines at 0.55MW and 0.6MW capacity, with a combined capacity of 8.65MW. The farm was built in two stages, with a potential expansion currently being assessed [9].

There have been significant advances in wind turbine technology since the construction of the Brooklyn wind turbine in 1993, resulting in an increase in turbine size as well as generation capacity [10].

New Zealand’s largest wind farm is the Tararua Wind Farm in the Manawatu, owned by TrustPower and initially constructed in 1999. 134 turbines collectively have a capacity of 161MW, and with average winds of 35km per hour, the farm’s performance ranks amongst the best in the world [11].

Wind farms in New Zealand

New Zealand wind farms either existing or under construction (green) or proposed (orange) 2013 [1]
Average wind speeds throughout New Zealand [16]

Wind is a plentiful renewable energy resource in New Zealand. Generating electricity from wind is a sustainable way for local, regional and national communities to meet energy needs [6]. New Zealand is suited to wind energy development because it lies across the prevailing westerly and north-westerly winds characteristic of the ‘Roaring Forties’ latitude of the country [12].

Coastal winds are typically of a higher speed and more consistent throughout the year than inland winds, so there is potential for wind farms to be built in coastal environments. The main exceptions are the Manawatu and Wairarapa regions; the prevalence of wind farms already constructed there confirming the potential of these inland regions [13]. In other countries, offshore wind farms have proved more successful than inland wind farms, but in New Zealand it is too costly to validate.

New Zealand currently has 17 wind farms operating (or under construction), with a combined capacity of 622MW. Proposals totaling a further 1914MW have been granted resource consent under the Resource Management Act 1991, or are in the process of gaining consent [14].

Wind farms are distributed in New Zealand based on the quality of the wind resource in certain regions [8]. Areas with good wind flow available have more turbines than others, such as the Southland, Manawatu, Wairarapa and Otago regions [15].

Issues associated with New Zealand wind farms

Decision makers are required to have regard to the potential effects of wind farms under the Resource Management Act 1991 [10]. Although there are various benefits to wind farms and wind energy in New Zealand, people interested in the state of the environment are more concerned with negative effects and how they are mitigated. Wind farms will only ever occupy a small proportion of New Zealand landscapes, even in the event of future wind power growth. Therefore national impacts will be relatively minor compared to localised effects [8].

Social

  • Effects on visual amenity are significant in locations in close proximity to where turbines are large and where they are placed on a prominent landform. Rolling hills are typical locations for wind farms in New Zealand [6].
  • Noise level and characteristics of noise from the wind farm. Noise is caused by the mechanical operation of turbine (the generator and gearbox) and from the aerodynamic sound of airflow over the turbines [8].
  • Health effects such as sleep disturbance from noise, operational and constructional safety concerns, and magnetic field effects have been found to be perceived rather than actual, as credible scientific literature has found no direct links [10].
  • Wind farms in New Zealand may affect sites of wāhi tapu, cultural and historical associations with landscapes, or a natural resource of value to Māori. Consultation with tanagata whenua is required during the consent process to examine the extent of cultural effects [10].
  • Shadow flickering of rotating turbines can provide annoyance to those living nearby, especially if the sun is setting or rising behind a turbine. It is suggested that this is only a problem when in close proximity to the turbines [6].

Environmental

  • Loss of indigenous vegetation and habitat fragmentation during construction. Land that is cleared for wind farms may then be exposed to exotic weed species infestation, and until some sort of vegetation cover has been restored; potential sediment erosion and run-off into nearby waterways [6,17].
  • Bird strike: the potential for collisions with turbines or other wind farm infrastructure. Has been found to be very limited in New Zealand, with no evidence of significant adverse effects on bird populations [10].
  • Air pollution associated with emissions from vehicles is primarily a problem during construction. Heavy vehicles are required to transport materials for the wind farm to and from the site on a regular basis during construction, but vehicle presence almost ceases once the wind farm is operational. Wind farms do not produce harmful gas emissions directly

Economic

  • Loss of agricultural production is possible where wind farm infrastructure takes up too much space in a farm. However, farmers in most cases can use their land almost as normal, and receive land rental payments from the electricity companies involved to offset any monetary loss of production [17].
  • It can be expensive to connect wind farms in a remote location to transmission lines, which could make the cost of wind-generated electricity more expensive than alternative energy sources closer to consumers.
  • It is perceived that homes or business in close proximity to wind farms would experience reduced market value, but no credible evidence exists that market value has been affected in New Zealand [10].

Environmental indicators

Environmental indicators summarise complex information about the environment into key measures so that the state of the environment can be understood. Indicators are measured regularly so that changes can be detected in the environment over time [18] to see if environmental quality is improving, getting worse or remaining unchanged. Indicators are also used to identify emerging issues, assess the efficacy of environmental policy in the long term and help develop new environmental policies [19]. The following existing indicators are measured by several regional councils and government agencies in New Zealand.

Social indicators

Social indicators tend to be measured with surveys to gauge the opinions, perceptions and attitudes of people. These social indicators greatly influence whether a wind farm will be built in any given area as the opinions of the people living in the area are taken into account and can decide whether a proposed wind farm goes ahead.

People's attitudes towards wind farms

Peoples’ attitudes towards wind farms vary greatly depending on several factors. Wind farm proposals are controversial and often divide communities. This indicator is significant because the attitudes of people as a nation influence the government and other decision makers in the decision of whether to consent and establish wind farms under the Resource Management Act 1991. If the majority of New Zealand citizens were against wind energy, it is unlikely that wind farms would be built here. The attitudes within the community in which a wind farm is proposed have a significant impact on whether the proposal will go forward. A survey carried out in 2004 for the Energy Efficiency and Conservation Authority (EECA) found that wind power is supported by 82% of New Zealand citizens if the turbines are visible on the skyline, and is at 90% if the turbines are not visible at all [8, 24]. A more recent EECA survey (2011) found that those supportive of wind energy are significantly more likely to be aged over 50 years old, own or partly own a house, be high earners ($70-100,000NZD per year) and to be one of an older couple with no children [24]. While support for wind energy in general is high in New Zealand, people often change their attitude if the wind farm will be located near them and directly affects them [24]. This is known as the ‘not-in-my-backyard’ (NIMBY) response.

It has also been found that people’s attitudes are influenced by the level of community involvement in projects. For example a ‘decide-announce-defend’ (DAD) approach is more likely to make a community opposed to a wind farm compared to involving the community in the early planning stages. If people feel powerless and uninvolved regarding what happens in their communities they are more likely to feel defensive [24]. There is more of a chance that people will have a positive attitude towards having a wind farm established in their local community if they feel involved in the planning process and that their concerns and feelings are being listened to and addressed [23].

Relationship between background sound level and recommended noise limits. From noise standard NZS6808 [22]


People's concerns about wind farms

There are many perceived concerns about establishing a wind farm in any given area. This is a significant indicator as people’s concerns directly influence their attitudes about wind farms and whether they will support the establishment of a wind farm in their local area or anywhere else in New Zealand. Noise is a key concern for many people. Wind farm noise is influenced by several factors: the design of the turbines, their distance from residential areas, the topography of the surrounding area, the age of the turbines (newer turbine technology tends to be quieter), current background noise levels, and the sensitivity of an individual person to noise [8]. In 1998, Standards New Zealand produced a standard for assessing and measuring the sound of wind turbines called NZS6808[22].

It states that sound levels measured at the boundary of any residential site must not exceed 40 decibels, or the level of background noise plus 5 decibels (whichever is greater). 40 decibels is considered to be similar to the sound levels in a quiet home or office. The noise limits in the standard are intended to provide protection against sleep disturbance and maintain a reasonable amenity in areas where wind farms are located [23]. It is not a mandatory standard and councils can apply their own noise limits in district plans and through resource consent conditions [8,23].

Wind turbines can be seen as a visually overpowering, intrusive and an unacceptable presence that ruins the amenity value of a landscape [8,24]. However not all people are concerned about visual pollution caused by wind farms, with some people finding their sculptural quality aesthetically pleasing. 0.1% of New Zealand citizens reported wind turbines as aesthetically beneficial in a 2004 survey undertaken by the EECA [8]. Some property owners near proposed wind farms may perceive that their property values will diminish due to the wind farm. However, to date there has been no credible evidence in New Zealand confirming that a wind farm has significantly affected the market value of a neighbouring property [10].

Environmental indicators

Wind farms produce very few negative effects on the environment. Most of these are associated with the construction process where vehicles transport the materials required to and from the site of the wind farm. There are therefore vehicular emissions associated with wind farm construction. Particulate levels and the concentrations of pollutants in the air (such as carbon dioxide) are environmental indicators of the state of emissions from vehicles, and are used to measure the effects of wind farm construction on the surrounding environment. It is best to examine the air quality directly at the construction site, as it would be difficult to isolate the effect of wind farm vehicles if measured anywhere else.

Economic indicators

Electricity consumption in New Zealand, 1947–2002 [27]

Total wind energy production and consumption

The quantitative amount of wind energy produced and also consumed within New Zealand are economic indicators that show the state of demand for wind-generated electricity in New Zealand. Demand has increased due to population and economic growth, and the increased consumption of electricity per person. Increasing demand has lead to a corresponding increase in electricity generation, including wind-generated electricity.

Wind farm statistics

The number of wind farms in New Zealand (existing, under construction or proposed) provides an indication of how New Zealand intends to generate electricity from wind to combat increasing demand. The New Zealand Wind Energy Association (NZWEA) expects wind-generated electricity to grow to 20% of New Zealand's total electricity generation by 2030, resulting in an increase in the size and number of wind farms [23]. The price of wind energy has reduced over time, while the price of energy from other sources has increased [8], making it an attractive option for consumers. In a survey carried out for the EECA, it was found that 58% of people surveyed were willing to pay more for energy generated from wind turbines if it raised their energy bill by 5%, and 34% of people are willing to pay up to 10% more for ‘green’ energy in general [24].

Trends

Cumulative installed wind capacity (MW) in New Zealand [25]

Production

The demand for electricity in New Zealand has been steadily rising at an average of 2.4% each year, an increase of 102% over the last 30 years. This rise has been due to both an increase in population and an increase in energy use per person [8]. To help meet increasing demand, energy generation from fossil fuels has increased from about 15% to 30% since 1977. This has caused carbon dioxide emissions from electricity generation to increase by 80% between 1990 and 2005 [8]. Wind energy is often considered to be the best solution to this problem, and wind-generated electricity production has been increasing over the last few decades. A major reason for this is that wind farm technology is now more accessible and the environmental benefits are better understood [8].

Cost

Wind generation is one of the cheapest forms of new electricity generation, as the cost of wind power technology has reduced over time [8]. In New Zealand, wind farms do not receive subsidies. Therefore developers will only build a wind farm if it can produce electricity at a price that is competitive with other sources of energy. NZWEA estimates the cost of wind energy to be between $70 - $120 per MWh. The reason for this variation in price is that there are many factors affecting the price of wind generated electricity. For example, wind speeds, the ability to maximise generation, construction costs, and capital costs can vary between wind farms[26].

Levels of support/opposition to wind energy in 1994 and 2004 [20]

Scale

To be economically competitive with other types of energy generation, proposed wind farms tend be large scale (both in farm size and turbine size) in New Zealand [8]. More electricity can be derived from larger turbines, therefore fewer large turbines are required to produce the same (or more) energy than many small turbines.

Attitudes

A major trend observed in several case studies from New Zealand is the decrease in support for wind energy when the wind farm will be located nearby to people. Generally speaking, public support for wind energy is very high in New Zealand, with 90% supporting it as long as the wind turbines are not visible from their home [24]. However this falls when wind farms are proposed in the local area (NIMBY response). Despite this, support often increases again once the wind farm has been established [20].

In 1994, rural New Zealand citizens tended to express higher levels of support for wind farming than their metropolitan counterparts. However, by 2004 this trend had reversed, with rural citizens expressing slightly lower levels of support than citizens living in urban areas [20]. A study in 2005 compared support for wind energy between 1994 and 2004 [20]. Figure shows the levels of support for wind energy in both 1994 and 2004.

Evaluation of management methods

Tararua wind farm [28]

Management of wind farms

Management of individual wind farms and the electricity generated from them lies with the energy company of ownership. Companies must ensure all wind farms are operating correctly and running to standards set by energy authorities. The management of wind farms contains various tasks, including general maintenance of turbine functionality, and the maintenance of roads leading to and within the wind farm. Potential and actual issues associated with wind farms in New Zealand are managed by government authorities under a range of relevant rules and regulations. The Resource Management Act 1991 is the primary guiding document.

Government authorities have a range of roles related to wind power. For example, the EECA's role is to promote renewable energy and develop strategies to reach renewable energy goals. The Electricity Commission's role is to oversee that electricity is produced and delivered to consumers in an environmentally sustainable manner. However, it has been reported that local authorities find it difficult to plan wind farms, manage impacts and respond to opposing viewpoints and pressures because in reality little guidance has been provided by central government [8]. Central government needs to ensure that authorities are working together effectively so that energy outcomes are sustainable. New Zealand would benefit from a strategic approach that provides consistent planning for wind energy growth [8].

Management of issues associated with wind farms

Cost is an important issue than needs to be managed effectively. Approximately 70% of the cost of building a wind farm is just the turbines, which are currently manufactured overseas. It is also important for energy companies to utilise sites with a high average wind speed and low turbulence levels, as turbulence incorporates change in wind speed and direction, which can hinder energy production [13].

Examining a wide range of indicators ensures that energy companies and government authorities can address wind farm issues. Indicators should be of utmost importance to authorities, because without awareness of the current environmental state, it is impossible to assess whether wind farms will remain viable in the future. For example, social indicators such as people's concerns and attitudes regarding wind power are important. Without community support, proposals will find the consent process very difficult, and are likely likely not to succeed. Therefore, surveys of public opinion should continue to be used as part of the planning process for wind farms. Once peoples opinion's are known, wind farm technology and construction can be adapted to minimise opposition. For example, it has been reported that people think that larger turbines are more graceful in motion because they rotate more slowly than smaller turbines [13]. In respect of this opinion, larger turbines could be used to mitigate visual pollution in locations where it was perceived to be a problem.

Lately there has been a large emphasis by manufacturers of wind turbines on trying to significantly reduce the tonal noise produced by wind turbines, as this type of sound is rather distinctive. Using few larger turbines instead of many small turbines can reduce the overall noise produced, mitigating noise pollution [13]. Ensuring that noise standards are updated and enforced in New Zealand is also a key management method.

Conclusion and Recommendations

Reasons for support of Tararua wind farm [24]

Wind farms in New Zealand are becoming more common, as fossil fuel depletion is encouraging the world to seek renewable sources of electricity generation. New Zealand has a plentiful wind resource that is perfect for wind energy generation. Wind farms in New Zealand cannot be fully effective unless potential or existing issues are mitigated. National and local New Zealand government authorities must use social, environmental and economic indicators if they are to mitigate associated issues and operate wind farms across New Zealand safely and successfully.

To create a wind farm with few issues, locations must be chosen that exhibit low levels of intrusion on the landscape; lowering the adverse effects on relevant communities and ecosystems. A study was completed about the reasons for support of Tararua wind farm in 2003. It is recommended that wind farms are planned in a way that increases support of communities and organisations, while still reaching sustainable energy goals outlined by the New Zealand Energy Strategy [24].








References

[1] New Zealand Wind Energy Association (2013) online: NZ Wind Farms http://windenergy.org.nz/nz-wind-farms/nz-wind-farms (Downloaded 20 September 2013).

[2] Energy Efficiency and Conservation Authority (2013) online: Renewable Energy http://www.eeca.govt.nz/efficient-and-renewable-energy/renewable-energy (Download 20 September 2013).

[3] Ministry of Business, Innovation & Employment (2013) online: Renewables http://www.med.govt.nz/sectors-industries/energy/energy-modelling/data/renewables (Download 18 September 2013).

[4] Ministry for the Environment (2009) Energy Supply and Demand: Environmental Report Card, Wellington: Ministry for the Environment.

[5] Ministry for the Environment (2013) online: http://www.mfe.govt.nz/publications/rma/nps-renewable-electricity-generation/nps-for-renewable-electricity-generation.html (Downloaded 20 September 2013).

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[7] New Zealand Wind Energy Association (2013) online:Brooklyn Wind Turbine http://windenergy.org.nz/nz-wind-farms/operating-wind-farms/brooklyn (Downloaded 22 September 2013).

[8] Parliamentary Commissioner for the Environment (2006) Wind, Power, People and Place, Wellington: Parliamentary Commissioner for the Environment.

[9] New Zealand Wind Energy Association (2013) online: Hau Nui Wind Farm http://windenergy.org.nz/nz-wind-farms/operating-wind-farms/hau-nui (Downloaded 22 September 2013).

[10] New Zealand Wind Energy Association (2013) Wind Farm Development in New Zealand; a Framework for Best Practice, New Zealand: New Zealand Wind Energy Association.

[11] New Zealand Wind Energy Association (2013) online: Tararua Wind Farm http://windenergy.org.nz/nz-wind-farms/operating-wind-farms/tararua (Downloaded 22 September 2013).

[12] New Zealand Wind Energy Association (2013) online: Wind Energy Resources in New Zealand http://windenergy.org.nz/nz-wind-farms/wind-resource (Downloaded 22 September 2013).

[13] Energy Efficiency and Conservation Authority (2001) Review of New Zealand’s Wind Energy Potential to 2015, New Zealand: Energy Efficiency and Conservation Authority.

[14] Graham, J. B., Stephenson, J. R. and Smith, I. J. (2009) ‘Public Perceptions of Wind Energy Developments: Case Studies from New Zealand’ Energy Policy 37 (9): 3348-3357.

[15] New Zealand Wind Energy Association (2013) online: Wind Farms Operating and Under Construction http://windenergy.org.nz/nz-wind-farms/operating-wind-farms (Downloaded 19 September 2013).

[16] National Institute for Water and Atmospheric Research (2013) online: Wind and Wind Energy http://www.niwa.co.nz/publications/wa/vol13-no4-december-2005/wind-and-wind-energy (Downloaded 24 September 2013).

[17] Borthwick, J E (2011) Mt Cass Wind Farm Environment Court Decision, New Zealand: Hurunui District Council.

[18] Waikato Regional Council (2013) online: About Indicators http://www.waikatoregion.govt.nz/Environment/Environmental-information/Environmental-indicators/About-indicators (downloaded 17 September 2013).

[19] Ministry for the Environment (2013) online: Environmental indicators used to Measure New Zealand's Environment http://www.mfe.govt.nz/environmental-reporting/about-environmental-reporting/national-environmental-indicators/environmental-indicators/index.html (downloaded 17 September 2013). [20] Baines, J. (2005) Public opinion surveys across New Zealand - trends, comparisons & messages, Wellington: Wind Energy Conference, Wellington, Tuesday, 30 August, 2005.

[21] Mason, I. G., Page, S. C. and Williamson, A.G. (2013) ‘Security of supply, energy spillage control and peaking options within a 100% renewable electricity system for New Zealand’ Energy Policy 60: 324–333.

[22] New Zealand Wind Energy Association (2010) The New Zealand Wind Farm Noise Standard, Wellington: New Zealand Wind Energy Association.

[23] Energy Efficiency and Conservation Authority (2011) Attitudes to Renewable Energy, New Zealand: Energy Efficiency and Conservation Authority.

[24] Berg, C. (2003) Minimising Community Opposition to Wind Farm Developments in New Zealand: Opportunities in Renewable Energy Planning, Wellington: Victoria University of Wellington.

[25] New Zealand Wind Energy Association (2011) Economics of Wind in New Zealand, New Zealand: Deloitte.

[26] New Zealand Wind Energy Association (2013) online: What does wind energy cost? http://windenergy.org.nz/wind-energy/costs (downloaded 30 September 2013).

[27] Meduna, V. (2013) online: Wind and Solar Power - Renewable energy in New Zealand, http://www.TeAra.govt.nz/en/graph/4916/electricity-consumption-in-new-zealand-1947-2002 (downloaded 19 September 2013).

[28] Wikipedia (2012) online: Tararua Wind Farm http://en.wikipedia.org/wiki/Tararua_Wind_Farm (downloaded 17 September 2013).

[29] Energy Efficiency and Conservation Authority (2008) Public Perceptions of Renewable Energy, New Zealand: Energy Efficiency and Conservation Authority.