Australian electricity options: wind

20 July 2020

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Dr Hunter Laidlaw

Science, Technology, Environment and Resources

Executive summary

Global electricity generation from wind has been increasing each year and now contributes almost 5% of all generation. This is mostly from onshore wind farms, but capacity from offshore wind farms is expected to expand in future years. A similar proportion of Australia’s total electricity generation is also from wind; however, this differs considerably across the country. As a variable source, there are challenges associated with integrating wind generation into electricity systems. However, electricity system operators around the world and in Australia are meeting these challenges to capture the benefits of this low cost and low emissions technology.

Australian electricity options are short briefings on the principal energy sources and storage options being debated in Australia, including: coal, natural gas, wind, nuclear, photovoltaics (PV) and pumped hydro energy storage (PHES).

The global COVID-19 pandemic and its economic consequences mean that statements and projections about future demand and pricing of energy options may no longer be reliable. Readers should note that some figures quoted in these briefings may pre-date the pandemic.

Global wind power

Harnessing the power of wind has a long history. Wind turbines were initially developed to mill grain or pump water but have more recently been adapted to harness the kinetic energy of wind for conversion into electricity. Multiple turbines may be co-located to form a wind farm, which may be either onshore (land-based) or in offshore waters.

Internationally, wind contributed about 1,268 terawatt hours (TWh) of total electricity generation in 2018—or around 4.5% of total global generation and 19% of total renewable generation. This was generated from 565 gigawatts (GW) of the world’s estimated 2,501 GW of total installed renewable capacity. Around 95% of this wind generation was from onshore wind farms.

Wind generation has become competitive with coal and gas electricity generation in a number of countries. New wind capacity increases have been relatively stable since 2016 but are expected to be lower over the next few years as growth slows in the USA and China. These two countries have the highest overall wind generation and capacity, while a number of European countries have the highest penetration of wind compared with their total electricity consumption (in particular, Portugal, Ireland and Denmark). About 47% of electricity consumption was derived from wind in Denmark during 2019.

During 2018, over three-quarters of the total global increase in new onshore wind capacity was delivered in China (19 GW), the USA (7.6 GW), the European Union (7.5 GW), India (2.4 GW) and Brazil (2.1 GW). The International Energy Agency (IEA) estimates onshore wind capacity could expand by 57% to reach 850 GW by 2024.

The capacity of offshore wind is expected to grow at a faster rate than onshore wind, with the IEA forecasting a threefold increase to 65 GW over the same period. About half of the growth in offshore capacity is expected to be in the EU, with much of the remainder in China. The IEA forecasts wind will generate about 23% of renewable electricity in 2024 (2,135 of 9,168 TWh), with about 90% of this wind generation from onshore wind farms.

Challenges of wind generation

As with other methods of electricity generation that are dependent on weather conditions, wind generation is variable but partially predictable (for example, weather modelling can provide an indication of expected generation). It can also be constrained by location, with many of the best sites for wind farms located away from where electricity is required. Wind generation is typically also decentralised, with more smaller generating units distributed over a larger geographical area compared with traditional electricity generators.

Wind farms can suffer from a lack of social acceptance due to perceived aesthetic, environmental and health concerns. These concerns have typically focussed on the visual impact of wind farms in the landscape, potential noise pollution, and their potential impact on wildlife (particularly birds and bats). The effects on birds can be considered relative to the negative impact of other structures (like windows), vehicle strikes, other forms of electricity generation or predation by cats (see Taylor and Kellow for further discussion).

Some materials used in the manufacture of turbines and their components may require mining to acquire the raw materials, and safe disposal or recycling at their end of life.

Wind turbines can be a source of audible noise caused by the movement of the blades through the air and components within the turbine. Exposure to such noise can impact people living or working nearby and some jurisdictions have therefore developed guidelines that set maximum sound limits for wind farms. Shadow flicker can also occur.

In 2015, the National Health and Medical Research Council (NHMRC) found no consistent evidence linking exposure to wind farms with detrimental health outcomes. The NHMRC identified areas for further research and has published a number of review and information papers on this topic. A summary published by the Environment Protection Authority Victoria on wind farms and sound can also be found here. In Australia, the National Wind Farm Commissioner role was established in 2015 to help address community concerns about proposed and operational wind farms.

Offshore windfarms have the potential to overcome some of these aesthetic, environmental and health–related issues, but can present their own challenges. These include issues around sea floor depth and requirements for anchoring the foundations to withstand ocean conditions, issues of access for installation and maintenance, interconnection to the land-based electricity network, and potential impacts on the local ocean environment.

Benefits of wind generation

The main benefits of wind farms include having no ongoing fuel requirement and not producing greenhouse gas emissions or other pollutants while generating electricity. While some emissions are generated during the manufacture, transportation, installation and decommissioning of turbines, these are low when spread across the turbine’s lifespan and relative to gas or coal power generation. Wind, as the ‘fuel’ for wind turbines, is freely available and not in limited supply (beyond any variation associated with the weather).

Site selection is obviously important in order to capture the best and most reliable wind resource. However, such locations may be some distance from where the electricity is used and this requires additional transmission infrastructure (which adds additional cost to projects).

Technological improvements are helping wind generators to integrate into the electricity network, while improvements in generation efficiency have helped wind to become the lowest-cost form of large-scale renewable energy in Australia. There has been a consistent trend over the last twenty years towards larger wind turbines (both on- and offshore), with increases in both the height of the turbine and the size of the rotor blades. These changes have helped to increase turbine capacity and lower the unit cost of electricity generation from wind.

Accurate wind forecasting, sufficient reserve capabilities and connectivity across regions are all important in allowing wind generation to operate efficiently and with minimal risk to supply security. Greater connectivity across regions can also be used to more easily transfer electricity to centres of demand, particularly when the generators are dispersed and may be experiencing different wind conditions. While these factors can allow wind generators to integrate more effectively into an electricity grid, intermittent generation can impact other generators in the system and these effects also need to be considered.

Wind farms can provide a sustainable way to generate electricity that is not reliant on non-renewable sources, thus avoiding some of the fuel security issues associated with oil, gas and uranium-based generation.

Wind power in Australia

Electricity generation from wind has grown rapidly over the last 10 years. Wind now generates over 7% of Australia’s electricity (an estimated 19,525 GWh of 265,117 GWh total generation in 2019). This trend is shown in Figure 1 with financial year data. This equates to just over one third of Australia’s generation of 55,481 GWh from renewable fuels, which exceeds hydro generation for the first time.

Figure 1: Australia’s total electricity generation from wind (and as a proportion of total electricity generation)

Source: Parliamentary Library calculations using data from Australian Energy Statistics, Department of Industry, Science, Energy and Resources, Table O1, May 2020.

Over 6,200 MW of wind generation capacity has been installed in Australia. A total of 837 MW of new capacity was installed during 2019, with an additional 5.5 GW either under construction or financially committed as at the end of 2019.

More than half of Australia’s electricity production from wind occurs in South Australia and Victoria. Wind is approaching 40% of total electricity generation in South Australia with over 5,700 GWh generation in 2018–2019 (see Figure 2 and this report). About 11% of Victoria’s electricity generation was from wind in 2019.

Developments in Australia have focussed on onshore wind farms, with offshore options being limited to date—mostly due to relative costs and the ocean depth in many locations. However, this may soon change with Australia’s first offshore wind project proposed off Gippsland in Victoria.

As a relatively mature technology, future onshore wind developments in Australia seem likely to be focussed on integrating the variable generation capacity of wind into the electricity system, such as expanding on wind energy forecasting systems and storage options.

Additionally, some turbine technologies use permanent magnets that require rare earth elements, the production of which may present other opportunities for Australian mining and industry.

There is also significant interest in coupling wind and other renewable electricity to hydrogen generation, which could open new energy opportunities both domestically and for export markets.

Figure 2: South Australia’s annual electricity generation from wind

Source: Parliamentary Library calculations using data from Australian Energy Statistics, Department of Industry, Science, Energy and Resources, Table O6, May 2020. Data for 2018–19 is an estimate.