The design of wind turbines is intended to transform wind into mechanical energy through the rotation of turbine blades. This mechanical energy is then converted into electricity using a generator housed in the nacelle, and the generated electricity is subsequently fed directly into the grid.

Wind turbines are designed to maximise energy output at low wind speeds, and 'depower' as wind speed increases, up to a certain 'cut out speed'. However, the electricity generated by the turbine is proportional to the wind speed cubed, up to their rated wind speed. For example, a wind turbine in 8m/s will generate 8 times as much power as that same turbine in 4m/s.

This is why it's important to place turbines in locations with consistent high winds to achieve the lowest cost generation for customers. Looking at a wind resource map of Australia, areas with a high average wind speed are tricky to find close to loads.

Modern onshore wind turbines (or Wind Turbine Generators, WTG) are generally 200- 270m high at the tallest point; the tip. The hub - where the blades connect to the Nacelle which houses the generator and other equipment - typically varies from 90 - 160m. The blades of a wind turbine are typically 40 - 90m.

During development approvals, projects usually get approval for a large 'envelope' of wind turbine dimensions so at the time of procurement the latest most innovative, and often larger turbine can be used on site. Higher, larger wind turbines can reach higher wind speeds at higher altitudes and can also generate efficiencies for a project through economies of scale for roads, foundations, cables etc.

Wind turbine dimensions are important to consider when designing the spacing between turbines to minimise wake losses and maximise efficiency. Although wind turbines are delivered to site in multiple parts before assembly, the component dimensions must be considered when planning the transportation route to site due to their large size.

Although larger, modern wind turbines are designed to reduce acoustic impact.

A wind farm will typically have a lifespan of between 25-30 years. The site conditions determine the design and life span of the turbines, based on the wind loads placed on the components. The components of the wind farm will have long term warranties of 25-30 years.

The operations and maintenance (O&M) phase of a project life will ensure the project is performing as expected and will conduct analysis and works to economically deliver the project design life.

Following operations, consideration will be given to extending the life of the project.

During decommissioning, the aim is to return the land in a state similar to its pre-development condition. This involves the removal of most infrastructure (but leaving tracks in place), remediation of the land, and making it available for the same activities as before, such as agriculture.

It is common that wind farms are 're-energised' at the end of life. This is because the project fundamentals will not have changed, at which point the condition of all wind farm components will be assessed for re-use or to be replaced.

Selecting a wind farm site involves a comprehensive evaluation and balancing process that considers various factors to ensure optimal energy production and minimal environmental impact.

Some key considerations are:

• Wind Resource Assessment and other meteorological conditions

• Geographical, Topographical and Waterway considerations

• Accessibility

• Land Use and Zoning

• Existing environmental values and potential impacts

• Grid Connection

• Infrastructure and Services

• Social and community values

• Cultural Heritage

• Economic viability

• Regulatory and Permitting Requirements.

Such criteria are also taken into account when considering the siting of each element of a wind farm. This includes where the substation be placed within a wind farm, or which way this road alignment should go etc. A development phase wind farm design will be conservative in its assumptions, and seek approvals for a broader 'envelope', including a micrositing zone. This broader envelope allows for later optimisation, flexibility, and avoidance of unforeseen constraints.

Around 85-95% of a wind turbine, by weight, is made from materials that can be recycled. Their outer shell, shafts, gearing and electrical components are typically made from steel, copper, aluminium, other precious metals and recyclable plastics. There is minimal oil used for the lubrication of some parts. This oil is contained within appropriate bunds within the shell of the wind turbine structure.

Wind turbine blades are made from different materials, most of which is fibreglass or carbon fibre. Composite materials, such as thermoset polymers, glass fibre, and carbon fibre, pose greater recycling challenges. These materials are commonly used to manufacture wind turbine blades, as well as the covers for the nacelle and hub.

The blades have a protective coating that is a polyurethane based lacquer that is non-toxic and contains negligible amounts of bisphenol A. The blades are specifically designed to have high resistance to weathering so will not emit either dangerous amounts of bisphenol A (BPA) or microplastics into the surrounding environment (including waterways).

Wear on wind turbine blades often make them unsuitable for reuse for their original purpose. However, there are several innovative ways that turbine blades or their raw materials can be reused or recycled in other building materials or repurposed for entirely new structures.

Engineers and scientists have found a way to turn fibreglass into a key component for the production of cement; an important material used in everyday construction. Whole blades have been repurposed as bike sheds in Denmark, noise barriers for highways in the US, ‘glamping pods’ across festival sites in Europe, or as parts of civil engineering projects, such as pedestrian footbridges in Ireland.

In recent years, leading wind turbine manufacturers have announced blade recycling innovations and products, demonstrating the industry's ongoing commitment to sustainability.

Wind farms are cheap and reliable sources of renewable energy over their lifetime. Generation capacity, capacity factor and efficiency are important but differing measures in the energy industry.

Capacity, measured in megawatts (MW) or kilowatts (KW), indicates the maximum electricity generation potential of a power station or wind turbine (sometimes 'nameplate'). Therefore, it would take 4 projects of the same size as Moah Creek Wind Farm (planned to produce 372MW) to be equivalent to Stanwell Power Station (1445MW).

The capacity factor gauges how much a plant actually generates over a time frame compared to if it always generated at maximum power, typically ranging from 30% to 45% in a year for wind farms. By contrast, Stanwell Power Station achieves higher capacity factors, with 67.4% in FY 21/22 and 63.7% in FY 20/21. This is consistent with the capacity factor for coal-fired power plants operating in the National Electricity Market (NEM) generally which was ~67% in 2020 (IEEFA, 2021). The capacity factor of gas-fired power plants in the NEM in 2020 was 16% (IEEFA, 2021). It should be noted that the NEM functions on a cost-effective principle. Consequently, if, during a specific bidding period, one energy source is more costly than another within the system, the system operator (AEMO) will not direct it to operate.

Efficiency varies among energy sources. Wind turbine generators range from 30-45% of the energy in the wind being converted to electricity, reaching 50% during peak wind. According to Betz Law, the maximum power extractable from wind is 59%. By comparison, Australian coal-fired power plants typically have an efficiency of 38% of the energy in the fuel being converted to electricity, while high-efficiency, low-emission (HELE) coal plants can reach 42-47%.

Sources:

Capacity vs Capacity Factor

https://www.energy.gov/ne/articles/what-generation-capacity#:~:text=The%20Capacity%20Factor&text=It%20basically%20measures%20 how%20often,of%20the%20time%20in%202021.

Capacity Factor of CFPP https://ieefa.org/wp-content/uploads/2021/06/Australias-Gasfired-Recovery-Under-Scrutiny_June-2021.pdf‍ ‍

Energy Efficiency of CFPP

https://whatswatt.com.au/what-is-hele-coal-power/

Energy Efficiency of WTG

https://css.umich.edu/publications/factsheets/energy/wind-energy-factsheet‍ ‍

Stanwell Power Corporation Annual Report 21/22

https://www.stanwell.com/story/annual-reports/‍ ‍

https://reneweconomy.com.au/australias-best-performing-wind-and-solar-farms-in-2021-and-the-leading-states/

A Community Consultative Committee (CCC) is established prior to construction and comprises community representatives who volunteer to engage regularly with the project team. 

The CCC is formed to facilitate structured and productive communication between RES and the community about the project, encourage community participation in decision making processes and address any concerns the community may have  regarding its processes.

For the Tarong West Wind Farm a CCC was formed at the start of 2024 and continues to meet quarterly.