As the world moves towards more sustainable and renewable energy sources, offshore wind has emerged as a promising solution. However, there are many misconceptions surrounding this technology.
We aim to provide accurate, up-to-date information about the potential of offshore wind energy in Australia.
All offshore wind projects in Australia are subject to environmental approval requirements under environmental legislation. This includes the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act). Approvals under the EPBC Act are required if the activity is expected to have a significant impact on a matter protected under Part 3 of the EPBC Act, including the environment of the Commonwealth marine area. Additional Commonwealth approval requirements will depend upon the nature and location of activities. This may include requirements under the Environmental Protection (Sea Dumping) Act 1981 and the Underwater Cultural Heritage Act 2018.
Projects must demonstrate how they will ensure impacts to protected matters will not be unacceptable and show how their projects will contribute to nature positive outcomes. Offshore wind project developers will need to seek all required approvals and licences under Commonwealth and state or territory legislation before any offshore infrastructure activities can occur.
We have developed specific guidance to assist industry to identify environmental risks associated with offshore wind projects and to outline what is required to address these risks.
Working out how long it takes for a turbine to displace the amount of carbon used in its manufacture, operation and decommissioning is called the ‘carbon payback’ period. The carbon payback period of offshore wind turbines can vary depending on several factors such as turbine type and location. A number of studies determined the carbon payback period for offshore wind turbines ranges from 5 to 12 months.
Offshore wind turbines have a lifespan of around 25 years but can be extended to 30-40 years with proper maintenance. Therefore, after the carbon payback period, offshore wind turbines can generate clean energy for many years with virtually no emissions, significantly offsetting any carbon produced during their manufacture.
Leading turbine manufacturers are taking steps to increase the sustainability of the sector through a combination of research and demonstration projects, and putting in place tangible targets:
- Siemens Gamesa, a major turbine manufacturer, has commenced production of 100% recyclable wind blade for offshore wind usage.
- Vestas has developed a new method of recycling epoxy-based wind turbine blades which uses a chemical process that can break down epoxy resin into virgin-grade materials.
- Several other major worldwide turbine manufacturers, have pledged to produce zero waste wind turbines by 2030.
The Australian Government is supporting wind turbine recycling technology in Australia through a $3 million grant to Industrial Property Maintenance and partners to develop a processing treatment and a pilot recycling facility for any type of wind turbine blades, including offshore blades. The grant was provided as part of the fourteenth round of the government's Cooperative Research Centres projects which focuses on the circular economy and priorities of the $15 billion National Reconstruction Fund.
This project presents an opportunity for a circular economy model for the green energy sector in Australia.
The noise from offshore wind farms won’t affect homeowners and people onshore. This is because offshore renewable energy zones start at least 10 kilometres from shore.
A typical land-based wind turbine produces a similar noise level as a standard refrigerator at a distance of 300 metres from the turbine. Given the distance of offshore wind turbines from shore it is not expected that the noise will be heard from shore.
Any potential impacts relating to noise will be required to be identified and assessed through the EPBC Approval process.
Naturally occurring electromagnetic fields (EMF) are present everywhere in the oceans. Undersea cables used for power transfer are also known sources of EMF. Three major factors determine the exposure of marine organisms to magnetic and induced electric fields from undersea power cables:
- the amount of electrical current being carried by the cable
- the design of the cable
- the distance of marine organisms from the cable.
The sensitivity of fish to EMF is based on the basic functions of their sensory organs.
A single, laboratory-based study found an increased rate of deformity in lobsters exposed to EMF, however the researchers concluded that further research is needed in situ (in the ocean) to understand the impact wind infrastructure has on lobsters. The same study also found EMF did not create a barrier for movement of lobsters.
There are a range of good practice management recommendations that may can be implemented to minimise potential EMF-related impacts. These are included in our key environmental factors guide. Any potential impacts relating to EMF will be required to be identified and assessed through the EPBC Approval process.
Offshore wind turbines capture part of the wind energy that passes through them and cause a disturbance known as wake. An Institute of Physics study in North America reported that this wake can travel up to 20 kilometres (sometimes further across open ocean in some conditions), but during the summer months, the effects on temperature were negligible.
We have released guidance to provide consolidated information to offshore renewable energy developers on the key environmental factors for consideration when developing projects in the Commonwealth marine environment under the EPBC Act.
A substantial amount of research has been conducted internationally investigating the environmental impacts of offshore wind. Research into the impact of underwater noise on marine mammals have led to mitigation measures such as sound protection measures, pingers and soft start methods of pile driving. Where research has identified collision risks with seabirds, mitigation measures have been recommended such as preparing a vulnerability index of species, avoiding migration flyways, integrating cumulative impact into environmental assessments, spatial planning, and reducing illumination and colour spectrum of navigation lights. The main conclusion of a World Wide Fund for Nature review was that with proper planning and mitigation measures it is possible to construct offshore wind farms without significantly damaging the environment.
The process for assessing and declaring areas as suitable for offshore wind considers input from all stakeholders, including environmental regulators and specialists, to avoid, as much as possible, known sensitive areas and migratory paths. However, EPBC Act and state or territory environmental approvals are still required by feasibility licence holders, prior to applying for commercial licences.
Offshore wind projects use a range of geophysical surveys to assist with their siting efforts. These typically use High Resolution Geophysical (HRG) surveys. Deep penetration seismic airgun surveys used to detect oil and gas deposits use high-energy sound pulses aimed at penetrating deep into the seafloor (thousands of metres). These are not necessary for offshore wind projects.
HRG surveys use sound sources that are much lower in energy than seismic airguns and have other important characteristics that set them apart from seismic airguns. The potential effects of HRG surveys associated with offshore wind development have been rigorously assessed in the Atlantic Ocean by the United States Bureau of Ocean Management and National Oceanic and Atmospheric Administration. These agencies concluded that HRG surveys are not likely to injure whales or other endangered species.
All offshore wind projects in Australia will be required to gain relevant environmental approvals, including under the EPBC Act. This process will include the identification of all potential impacts of the construction and maintenance of the wind farm, and mitigation measures. Some measures can be implemented to protect against the sound generated during HRG surveys, for example exclusion zones around vessels and visual monitoring by independent trained professionals that look for marine mammals to minimise the possibility of vessel strike and shut down any sound sources if marine mammals are detected within a certain distance.
Sharing the space
It’s our priority to manage the offshore marine environment in a way that recognises all users and balances competing interests. Understanding existing users and interests in and near potential offshore wind areas is important.
There are consultation opportunities to consider the views of existing offshore industries and ensure that any new offshore wind development can co-exist alongside other industries, such as fisheries, tourism and shipping.
Consultation between a licence holder and existing marine businesses is required during all stages of the project: in the development of a project management plan for feasibility works, during the environmental approval process including public consultation, and for the overall project management plan leading to a commercial licence that allows construction.
The visibility of offshore wind farms depends on factors such as the distance of the turbines from the shore, the size of the turbines, the weather conditions, and the curvature of the Earth.
We understand that visual impact is an important concern of the community. We also acknowledge that visual appeal of turbines is subjective. We have received mixed feedback, where some people do not like the look of turbines, while others consider them visually appealing.
The proposed Illawarra region consultation page has pictures of what offshore wind turbines may look like from various locations. Visit the proposed offshore wind area: Pacific Ocean off Illawarra region consultation.
The height of wind turbines to be used in proposed Australian projects has not been decided yet. Individual projects that receive a feasibility licence will need to undertake surveys to determine the size of turbines that they will use. The Hunter declared area has a turbine height limit of 260m, which was a requirement to ensure any offshore wind farms can coexist with Defence activities.
Marine and aviation safety regulations require the use of warning lights to mark obstacles.
Marine lights, visible up to 18.5 km, are placed at a height that limits their visibility from the shore.
Aviation lights are red and placed on the wind turbine’s nacelle. These are visible from over 30 km away for aircraft safety. Their intensity decreases substantially with distance. Weather and atmospheric conditions can also affect light visibility.
If an area is declared suitable for offshore wind, applications for feasibility licences will be invited. All applications will be considered against the legislated merit criteria. It is important to note that this is not permission to construct an offshore wind farm.
Construction activities cannot commence without a management plan that has been approved by the Offshore Infrastructure Regulator. The licence holder must demonstrate how co-existence with marine businesses will be managed as well as outline how the project will address issues such as how licence activities will be conducted including the approach to decommissioning.
Part 2, Division 2 of the Offshore Electricity Infrastructure Act 2021 outlines the process the Minister must follow when deciding to declare an area. This process involves consultation across all levels of government, First Nations people, existing users of the marine environment and communities.
Members of the public are given a minimum of 60 days to provide feedback on any areas proposed for declaration.
Offshore wind turbines are a proven commercial technology, with significant amounts of deployed capacity across the world. They are designed to withstand harsh weather conditions such as strong winds, high waves, and saltwater corrosion. Offshore wind foundations provide stability and support for the turbines.
Like all forms of machinery, offshore wind turbines require regular maintenance. Maintenance provides local businesses with economic opportunities to service offshore wind farms. Mature markets, such as the UK, have been operating and maintaining offshore wind farms for over 20 years, with well established practices and standards.
Offshore wind is a source of high-capacity, reliable renewable energy. In the UK, which has a total installed capacity of 13.7 gigawatts of offshore wind energy, offshore wind is expected to produce enough electricity to meet the needs of nearly half of UK homes by the end of 2023. The first offshore wind farm started operating in the UK in 2000.
The term capacity factor indicates how fully a plant’s capacity is used, depending on the wind conditions. Improvements in turbine technology and wind conditions further offshore can improve capacity factor. Capacity factors are generally 10 to 15% higher for offshore wind relative to onshore wind.
A 2018 study concluded that having an ocean view including a wind farm had no significant impact on property prices, in comparison to having a sea view without a wind farm. Another study conducted by Hoen in 2013 found no significant impact on property values post-wind facility construction.
- Find out more about offshore wind in Australia
- Read more about proposed offshore wind areas
- Read more about building an offshore wind industry
- Read more about legislation and regulations
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