In 2014, a preliminary study of the offshore wind potential of the South Taranaki Basin was conducted at the University of Canterbury by Dr. Ian Mason and two students to investigate the question 'Why is offshore wind not on the table in NZ?' The research, using wind speed data from the Māui A mast, plus marine maps, concluded that the South Taranaki Basin looked very promising as a location for possible offshore wind development.
In 2018, a more detailed study was conducted by post-graduate student Chiraag Ishwar, supervised by Dr Ian Mason, using a 5-year record of 10-min wind data from the Māui A and Māui B platforms and Arc-GIS mapping of NIWA bathymetry data. This work concluded that approximately 7GW of fixed foundation turbines could be accommodated in the area, generating about 28,500 GWh/y. The research was reported in a paper presented to the Electricity Engineers Association (EEA) Conference in Auckland in June 2019, where it generated considerable interest.
In early 2019 Justine Gilliland, then Chief Executive of Venture Taranaki, was considering whether offshore wind energy might be an option for the Taranaki region and decided to commission a discussion document on the topic. Venture Taranaki then read the 2019 EEA paper and Chiraag Ishwar was engaged to work with Elemental Group on the project. The discussion paper entitled Offshore Wind: A New Energy Opportunity for Taranaki was released in April 2020.
Following both the EEA paper and the Venture Taranaki paper developers and investors contacted the respective authors and expressed keen interest in offshore wind developments in NZ.
Offshore Renewable Energy Forums
- A series of offshore renewable energy forums commenced in 2020 when Venture Taranaki initiated the Offshore Wind Forum, which was held in New Plymouth in December of that year.
- This was followed in November 2021 by the Offshore Future Energy Forum jointly hosted by Ara Ake and Venture Taranaki in New Plymouth.
- In March 2023, Ara Ake and Venture Taranaki hosted the Offshore Renewable Energy Forum in New Plymouth.
- In 2022 the NZWEA hosted a very successful Offshore Wind Wananga in Wellington ahead of the annual Wind Energy Conference.
These gatherings have become key events in the offshore energy calendar in NZ.
The Offshore Wind Working Group (OWWG)
The Offshore Wind Working Group was co-founded in late 2019 by Dr Ian Mason and two consulting engineers Giacomo Caleffi and Peter Spencer (both with ISC Consultants) with the aim of creating an open-source information sharing and networking platform for professionals with an interest in offshore wind development in Aotearoa New Zealand.
This attracted a wide range of expertise and interest from engineers, developers, academics, environmental scientists, lawyers, unionists, regional development professionals, and regulatory specialists. In August 2021, the group became part of the New Zealand Wind Energy Association, and Giacomo Caleffi became the first Chair of the OWWG. Following Giacomo's move to Copenhagen Offshore Partners in 2022, Tom Young (Infrastructure Sustainability Council) was elected Chair.
In May 2023, Tom Young resigned from OWWG, following his announced move to the BlueFloat Energy/Elemental Group partnership. A replacement Chair will be announced in June 2023.
For more information see OWWG page with purpose, aims, member list, steering committee, meetings etc.
Government Support/Developing the Regulatory Environment
Following the Venture Taranaki discussion paper and the offshore renewable energy forums of 2019 and 2020, at the offshore renewable energy forum in late 2021 the Government announced work would commence in 2022 to develop regulatory settings to enable investment in offshore renewable energy (such as offshore wind farms) and innovation. This was then included as an initiative in New Zealand’s first Emissions Reduction Plan in 2022.
This was supported in May of 2022, by the New Zealand Infrastructure Commission which released a strategy including a recommendation to develop and establish a regulatory framework for offshore renewable energy.
Offshore wind developers now have the initial support and Government commitment that has been needed for them to realistically look at offshore wind developments in Aotearoa New Zealand.
Offshore wind basic principles
Offshore wind farms consist of arrays of wind turbines along with electrical substations located out to sea. This is for several reasons including typically stronger and more consistent winds, less turbulence, low visual impact and the elimination of noise issues. Because of these factors, larger wind farms are possible, far exceeding the typical size of onshore wind farms.
In 2023, turbines are generally fixed to the seabed, in waters up to 60m deep. The development of floating turbines means that developers can now consider waters in the 100-200m depth range.
Offshore wind farm development involves a wide range of activities and skills. Wind resource assessment, electrical engineering, civil engineering, marine life study, bird studies, port construction, and manufacturing are some examples.
For more detailed information and discussion:
So why offshore wind?
Offshore wind is attractive for New Zealand due to the world class wind resource and suitable seabed depths in certain areas off our coasts, plus the potential for floating turbines to be installed in deeper waters. This would enable New Zealand to dramatically scale-up electricity production, reach 100% renewable electricity generation, and potentially develop several new energy intensive industries.
Offshore wind turbines generally have a very high capacity factor (CF), which is the ratio of electricity produced to that possible if the turbines generated full power all the time. Estimated CF values for offshore wind in the South Taranaki Basin, for example, are around 50% at the grid injection point (accounting for array losses, cabling losses, sub-station efficiency and downtime). For onshore wind in NZ the measured CF is around 40% and estimated CF values for utility-scale solar PV are approximately 15% - That means that an offshore wind farm could produce about 1.25 times as much electricity as the same size onshore wind farm, and 3.3 times as much electricity as the same size solar PV system.
Offshore wind is typically more consistent and less turbulent than onshore wind. However, our onshore wind resource is also world class, and this advantage may be less pronounced than is the case in other countries.
One of the major advantages of offshore wind farms in that they have a low visual impact and noise is unlikely to be an issue. In NZ offshore wind farms are expected to be located at least 20 km from the coast.
Current state of offshore wind in NZ
As of February 2024, there are five NZWEA member offshore wind developers who are interested in developing projects in Aotearoa New Zealand.
- BlueFloat Energy NZ / Elemental Group
- NZ Super Fund / Copenhagen Infrastructure Partners Joint Venture (Taranaki Offshore Partnership)
- Oceanex Energy NZ Limited
- Parkwind
- Sumitomo Corporation
Developers are implementing feasibility studies, and working to build relationships with iwi, hapū, communities, energy sector participants and key stakeholders to understand their interests and aspirations.
New Zealand’s big advantage and draw card to developers is the quality of offshore wind, where Taranaki, Waikato, South Wellington and Southland have been identified by researchers and developers as prime locations, also due to the relatively shallow seabed.
Transpower have forecast that electricity demand will grow from 43 TWh/y to between 70 TWh/y - 88 TWh/y by 2050 under the green hydrogen scenarios highlighted by MBIE (ref. The Whakamana - Te Mauri Hiko Monitoring Report March 2023) and offshore wind is looking to play a significant role in helping Aotearoa New Zealand achieve this while also achieving its climate goals of having a 100% renewable electricity system by 2035 and net zero carbon emissions by 2050.
Current Developers
- BlueFloat Energy NZ / Elemental Group
- NZ Super Fund / Copenhagen Infrastructure Partners Joint Venture (Taranaki Offshore Partnership)
- Oceanex Energy NZ Limited
- Parkwind
- Sumitomo Corporation
FAQS
How much electricity do turbines produce?
It is expected that over the next decade typical commercial offshore turbines being installed internationally will have a capacity of more than 18 MW each which means they could generate about 90 GWh/y of gross power.
Wind turbines currently used for offshore applications are generally much larger than onshore, at 12 MW - 14 MW capacities, and are up to around 220m in rotor diameter with a top blade tip height of around 260m.
How do offshore windfarms work?
Power is generated from offshore wind using turbines installed out at sea. Through a series of cables electricity is transmitted to an offshore substation where it is collected and exported to an onshore substation. Once there it is distributed via onshore grid infrastructure to power homes, businesses, and industry.
Will they be visible from the coast?
Depending on the distance of the wind farm from land, the offshore wind farm may be visible from some coastal areas. However, this will depend on the weather conditions and the design of the project. A project may have some (unavoidable) visual impact however it can be minimised through careful location, and colouring. The attractiveness of wind turbines is subjective; however, many people consider these slowly rotating giants to be very graceful.
What locations are the offshore windfarms?
There are currently no confirmed locations, but South Taranaki, Waikato and Southland are being looked at as potential locations.
Does it affect our fishing industry?
Offshore wind farms are typically built quite a long way out at sea. While they occupy a reasonably large area, boats may be able to pass in between turbines with few restrictions. There is some evidence that the presence of wind turbine foundation structures attracts sea life to the area. Indeed, the area can provide a refuge for sea life where they are protected and can find plenty of hard substrate to feed, hide and breed.
How long do the turbines operate for and what happens at the end?
Typically, in the range of 25-35 years for turbines and steel structures and longer for concrete components, dependent on site and project conditions.
Most turbine components can be recycled. Historically, blades have been the most challenging element to recycle. Manufacturers are actively working on improving the recyclability of blades and there is ongoing research and development in this area, which is gaining considerable momentum.
Why use floating or fixed foundations?
Most offshore wind turbine foundations are driven directly into the seafloor and can be installed in waters up to 60m depth. Floating turbines have recently been developed which are tethered by chains to the seafloor. These floating turbines can operate in much deeper water. Specialised vessels and offshore support services are required for installing and maintaining offshore wind turbines.
Why do we need to build offshore windfarms when we have so many onshore windfarms already built, being built or consented?
Both onshore and offshore wind energy will be needed to meet New Zealand’s and the world’s increasing demand for clean energy. Offshore wind farms harness the typically stronger and more consistent winds found out at sea and don’t take up valuable land.
The more renewable energy we can build, the faster we can reduce our emissions and help achieve the nation’s climate change targets.
How does the electricity from an offshore windfarm get to where it needs to be – homes and businesses?
Both onshore and offshore wind turbines are normally organised as wind farms involving multiple turbines connected to common infrastructure for transmission. In New Zealand’s case this is the national grid operated by Transpower.
What is the carbon footprint of an offshore wind farm?
The electricity produced from an offshore wind farm is free of greenhouse gas (GHG) emissions. However, GHG emissions do occur during the construction, operation and decommissioning of the entire system over its lifetime, and this constitutes the carbon footprint.
Published studies between 2009 and 2014 found carbon footprints for offshore windfarms of 5.2 -32g-CO2e/kWh.
One European developer has reported an embodied carbon footprint for offshore wind of approximately 6g-CO2e/kWh, which is consistent with the low end of this range, and with a future projection of approx. 4.5 g-CO2e/kWh for wind in general.
Since a modern large wind turbine comprises more than 85% iron and steel, the introduction of green iron and steel (made using hydrogen instead of coal) will dramatically reduce the carbon footprint of offshore wind farms in the future.
In addition, the increasing deployment of electrically-powered and hydrogen-fuelled support vessels will further lower the emissions from offshore wind farm operations and the overall carbon footprint.