Wind Power: Renewable Energy

Wind power is one of the cleanest sources of renewable energy. We outline the main types of wind farms - onshore and offshore, as well as floating parks. Read about the benefits and future prospects of wind energy and how it can help us tackle climate change. Switching is not without drawbacks - we cover wind capacity, battery storage and environmental concerns.
Crowded Onshore Wind Park in California
Wind turbines in the Californian mountains. Eyesore or the solution to climate change? Photo: © Erik Wilde. CC BY-SA 2.

Along with solar power, wind power is one of the fastest growing types of renewable energy in the world. It is a clean and free source of sustainable energy, which can help us tackle climate change by reducing our reliance on fossil fuels like coal, oil and gas.

According to a new report by the International Energy Agency (IEA), offshore wind energy could generate 11 times more electricity than the world needs, and could attract $1 trillion in investment by 2040. 1

However, right now, the benefits of renewable energy are not being properly felt, because – despite enthusiasm for renewables – both wind and solar power still account for a tiny percentage of global energy supply. This should change when scientists find a cost-efficient way to store their power when the wind isn’t blowing or the sun isn’t shining. In this connection, see: Hydrogen Energy: Tomorrow’s Clean Fuel.

What Is Wind Power?

Wind power is the use of wind to generate electricity. Technically wind power is a form of solar energy. Sunlight strikes the planet unevenly, causing areas of warmer and less warm air. This causes the Earth’s climate system to even out the atmospheric pressure by creating wind, a form of energy based on kinetic motion. That motion can be harnessed to turn wind turbines and generate electricity.

A standard ‘wind machine’ is called a wind turbine or aerogenerator, and a group of turbines is known as a wind farm or wind park

Two Main Benefits of Wind Power

There are two main benefits to be gained by using wind energy. First, wind power is carbon-free; no greenhouse gas emissions are created in the energy process, although building the wind turbines does rely on the use of fossil fuels and therefore does create a modest amount of carbon emissions.

This makes wind power – along with other renewables like organic biomass and biofuels, geothermal energy, solar energy, hydropower, as well as next generation sources like wave power and tidal power as well as storable hydrogen energy – a key feature of our climate plan to stabilize global warming and regain control of our climate.

The second benefit of using wind energy concerns pollution. Because no fossil fuels are burned, there is none of the regular air pollution, such as smog in urban areas.

Wind Share of Primary Energy (2019)

Wind energy share of global electricity
Source: Our World in Data based on BP Statistical Review of World Energy (2020).

What Is The Potential Of Wind Power?

Wind power accounts for just 4.7 percent of global electricity production in 2019. 2 In Europe, however, wind accounts for a significantly higher percentage of energy needs. In Denmark, for example, 48 percent of electricity comes from wind. In Ireland, 28 percent; Portugal, 24 percent; and Germany, 21 percent.

In total, wind power supplies 15 percent of the electricity consumed in Europe (2019). Also in 2019, some 83 other countries added wind power to their power grids. 3

World Electricity Generation by Power Source: Projections

World Electricity Generation by Power Source: Projections
The present fossil fuel-heavy power mix is projected to undergo a dramatic change and become dominated by renewables by 2050. While hydropower still makes a significant contribution, the largest producers of power, will be solar PV and wind, with solar PV equaling the sum of onshore, offshore fixed and offshore floating wind. Floating offshore wind will be an exciting new market with 250 GW installed, producing 2% of global power in 2050. Source: Energy Transition Outlook Report 2020 – DNV GL Group and IRENA 2019

The amount of wind power that can be captured and converted into electricity is immense. At the end of 2019 wind had a global cumulative capacity of 651 GW and has a projected capacity of 5806 GW by 2050. 4 Even by 2030, this projected scenario would save about 23 billion tons of carbon dioxide from entering Earth’s atmosphere and create millions of new jobs in renewable energy industry chains. 3

Wind energy is at the heart of energy transition and our shift to a low carbon, sustainable future. One of the effects of COVID-19 on climate change has been to temporarily reduce the emission of greenhouse gases, due to a decline in energy demand.

In response, the Global Wind Energy Council called on governments to use their economic recovery plans to invest in a greener future by introducing electric vehicles (EVs) and electrifying public transport, heating and industry. 5

One of the main causes of global warming has been the burning of coal for electricity. But in 2019, the use of coal in power generation fell 3 percent, mainly due to the rise of wind and solar power. A fall in demand for electricity, as well as the replacement of coal with lower carbon fuels (such as natural gas in America and the EU, and nuclear energy in China and India. 6 

Unfortunately the transition to cleaner energy is not happening fast enough, and it is not yet clear if the fall in coal use, is the ‘new normal’. If we are to have any chance of meeting the 2-degree target set by the Paris Climate Agreement, coal fired electricity needs to fall by 11 percent every year until 2030.

On the plus side, wind and solar are more cost-competitive today than new-built coal or gas plants in about two-thirds of the world. In the next decade, it will become more cost-efficient to build new wind and solar farms than to run existing coal or gas plants. 4

There is unprecedented political momentum behind climate action and the scaling up of wind and other renewable energy technologies. As young people around the world take to the streets in response to the crisis, more people are beginning to realize that the window for taking action on a sufficient scale to preserve a habitable planet, is narrowing.

Who Generates The Most Wind Power?

According to Wind Energy International (2020), the following countries account for more than 80 percent of global wind energy in 2019:

CountryPercentage of Global Wind Energy Production (2019)
China36.3 %
USA16.2 %
Germany9.4 %
India5.8 %
Spain4.0 %
UK3.6 %
France2.6 %
Brazil 2.4 %
Canada1.1 %
Source: Wind Energy International (2020)

Top 10 Wind Farms In The World

Wind FarmLocationCapacity and Turbines
Jiuquan Wind Power BaseChinaThis is the largest wind farm in the world with 7,000 turbines. At peak capacity, this wind farm has the ability to generate an impressive 20 GW. However it is working at less than half its capacity. This is due to weak local demand. It’s location in the Gopi desert means that it is very isolated the infrastructure is not there yet to transmit the power to areas with denser populations.
Muppandal Wind FarmIndia3,000 turbines and a peak capacity of 1.5 GW.
Alta Wind Energy CentreUSAThis is the largest wind farm in the USA. It has 490 turbines, all of which help to supply energy to Southern California. Peak capacity of 1.5 GW.
Jaisalmer Wind ParkIndiaThis wind park consists of several wind farms: Amarsagar Badabaug, Tejuva, Soda Moda and several others. Collectively, they generate 1 GW.
Shepherds Flat Wind FarmUSALocated in Arlington, East Oregon. It has 338 turbines, covering 30 square miles. This wind farm generates 845 MW.
Roscoe Wind FarmUSALocated in Roscoe, Texas. It has 634 turbines and generates 780 MW.
Horse Hollow Wind Energy Centre.USALocated in Texas. It has 421 turbines and can generate 735 MW.
Capricorn Ridge Wind FarmUSALocated in Texas. It has 407 turbines and can generate 662 MW.
Walney Extension Offshore Wind FarmUK

Offshore
This is the largest offshore wind farm in the word. Its location in the windy Irish Sea is perfect for generating 659 MW of power.  Currently operates 189 turbines which cover an area of 145 square km.
London Array Offshore WindfarmUK

Offshore
Covers an area of 100 square km off the coast of Kent. Operates 175 offshore turbines with the ability to generate 630 MW of power.

Types of Wind Farms

Onshore Wind Farms

Onshore wind farms are exactly as they sound – wind turbines constructed on land as opposed to offshore in water. They are usually located high up, in low density rural areas far from towns and cities.

Six of the world’s largest 10 onshore wind farms are based in the United States. These include the 1,548MW Alta Wind Energy Centre in California, the 845MW Shepherd’s Flat Wind Farm in Oregon (845MW) and the 781.5MW Roscoe Wind Farm in Texas (781.5MW).

China is the world leader in wind energy production, with a third of the world’s capacity. The onshore park Jiuquan Wind Power Base in Gansu Province is the biggest in the world, with more than 7,000 wind turbines. It is five times larger than its nearest rival. However, despite it’s size, it is still operating at less than half its capacity due to weak demand and local government preference for coal fired power stations. 7

One of the key benefits of onshore wind farms is that they are cheaper to build and more accessible than offshore environments, and they can be connected directly more easily to local power grids.

However, they have met with stiff opposition from activists who object to the visual blight they pose on the landscape, the proximity to their homes and the impact on nature, particularly birds. In some countries like Germany and Norway, citizen opposition has brought most onshore wind development to a halt.

While onshore wind farms are still more common today, as technology evolves and costs come down, there is growing interest in offshore wind farms as an alternative.

Offshore Wind Farms

Offshore wind farms are constructed in shallow water, such as lakes and coastal ocean water. The first offshore wind farm was built in 1991 off the coast of Denmark at Vindeby, in relatively shallow waters (2–5m). Since then, many more have been constructed especially in the Baltic Seas, Europe, USA and China. As of 2020, the 1.2 GW Hornsea Project One in the United Kingdom is the largest offshore wind farm in the world. In the years since the Vindeby was built, turbines have been increasing in size, generating more and more power.

Most existing offshore wind farms are in shallow waters, generally less than 20m deep. These wind types are mounted on single monopiles which are driven into the seabed or rest on concrete bases.

In deeper water depths, between 30m and 60m, wind turbines tend to be mounted on tripods, such as the Alpha Ventus wind farm in Germany. For waters deeper than 60m, a new technology called floating wind farms has been tested since 2020. Monopiles and tripods are considered proven technology, floating wind farms are still new.

While offshore energy is relatively cheap, it still requires huge upfront investment to build a wind farm owing to several issues such as more difficult installation procedures, structures and working conditions. In 2019, offshore was responsible for only 10 percent of global investment in wind power. 4

In 2020 the EU Commission unveiled an ambitious plan to increase offshore wind power 25-fold by 2050, while the UK declared its intention to generate enough electricity from the country’s offshore sites, to power every home in the UK within a decade. 8

What’s more, in 2020, the IEA boldly stated that offshore wind could generate 11 times more electricity than the world needs and could attract $1 trillion in investment by 2040. 1 The report is worthy of note, not just because of the enormous claims it makes about wind power, but because the IEA was long seen as skeptical about the potential of renewable energy.

The problem: Such a massive increase in near-shore wind farms may not be completely feasible, in part because of growing opposition from coastal residents, fishing fleets and conservation groups. But also because there may not be enough coastal land. This is where floating farms may provide part of the solution.

Floating Wind Farms

In contrast to ordinary offshore wind turbines which are bolted into the seabed, floating turbines are built on top of floating structures which are anchored to the sea bed by long chains. This means they can access ocean waters up to half a mile deep, where winds blow strongest and more consistent.

In places like the UK, Norway and Germany, where density of onshore and near-shore turbines is already high, floating turbines which can be installed out of sight of coastal residents, are certainly attractive.

But floating wind farms are still at an early stage of maritime engineering, and as of 2020, the only operational farm is the 30MW Hywind Scotland, although two others – the 50MW Kincardine in Canada and the 88MW Hywind Tampen project in Norway – are nearing completion.

How Offshore Wind Farms Work
How offshore wind works. Bureau of Ocean Energy Management (BOEM), United States Department of the Interior.

Some renewable energy experts remain skeptical that the high costs of floating offshore wind turbines will come down far enough without subsidies to rival other clean-energy technologies. Currently the electricity they generate is about twice the price of near-shore wind turbines and 3 times that of land-based wind turbines. 9

Indeed, maritime engineering may always make floating turbines more expensive to build, deploy and maintain. After all, it is hard to build robust and secure wind farms in water half a mile deep. Lifespans of the stations are also going to be shorter due to the corrosive nature of the marine environment.

Transportation of huge blade for a wind turbine
The blade of a wind turbine being transported in Iowa, United States. While wind power is carbon-free, the life-cycle emissions of manufacturing, transportation, construction and recycling of turbines, are significant. Larger turbines have a smaller carbon footprint because they generate more energy. Today, diameters can surpass the length of a football field. But practical limitations and local rules could place a ceiling on size in the future. Photo: Acroterion/CC BY-SA 4.0

The Problems of Wind Power

Capacity Issues

The nameplate capacity (also known as installed capacity) of a wind turbine is the amount of energy the turbine would produce if it ran 100 percent of the time at optimal wind speeds. Wind turbines range in nameplate capacity from less than 1 megawatt (MW) to more than 3 MW.

But because the wind doesn’t always blow, wind turbines generally only operate at about 30 per cent of their maximum potential output.

A more useful number to know is capacity factor. This is a measure of the actual energy produced over a specified period of time, divided by the nameplate capacity. Capacity factors of wind plants may vary from 15 to 50 percent depending on the turbine type, location, and wind consistency and strength.

As nameplate capacity of wind farms can be misleading and lead to false assumptions of productivity, it begs the question what are global wind power targets based on? If they are based on nameplate capacity, are those targets realistic?

Storage Issues

Electricity is very difficult to store and to date no feasible, cost effective, grid-scale storage technology has yet emerged. Consequently, intermittent electricity needs to be backed up by conventional generation to provide power on demand – a basic expectation in a modern world. No conventional generation has been closed down yet because of wind power.

Greenhouse Gas Emissions

Wind power produces clean energy. However, it does create a carbon footprint at the manufacturing and installation stage. For example, the extraction and transportation of raw materials, the manufacturing of the various parts of the wind turbine, and the transportation of the turbine to its destination, all create emissions.

Also, the manufacturing and installation process, creates significant cement emissions, which are the second-biggest contributor to greenhouse gases after fossil fuels. A 5 MW turbine requires an average of 150 metric tons for the reinforced concrete foundations, 250 tons for components of the turbine (rotor hubs and nacelles), and 500 tons for the towers. 10

A life cycle assessment (LCA), is one way to assess the overall environmental impact of wind power because it takes in the production phase. When LCA is applied, it is clear that renewable sources of energy like wind power and PV panels for solar energy have a significant carbon footprint.

Wind Energy Payback Period

One recent study concluded that the energy payback period of a wind turbine was 8 months 11. Most studies show the payback period, depending on the size and location of the facility, is somewhere between one and two years.

According to the National Renewable Energy Laboratory (NREL) – total life cycle greenhouse gas emissions from renewables and nuclear energy are much lower than those from fossil fuels. For example, from cradle to grave,
coal-fired electricity releases about 20 times more greenhouse gases per kilowatt-hour than solar, wind and nuclear electricity. 12. This makes wind power an essential element in our strategies for both climate change mitigation and adaptation for the rest of the century and beyond.

However, until all energy used to produce and maintain wind farms come from renewable sources – humanity will remain dependent to some degree on fossil fuels.

Visual and Noise Pollution

Visual and noise pollution from land based wind turbines is also a problem. While people generally have a positive attitude towards wind farms, installation is often met with opposition from local communities on the basis of “not in my back yard”. One study showed that nearby wind turbines reduces residential sales price by between 3-7 percent. 13

In an open rural landscape, wind turbines look artificial and degrade a scenic view. The perpetual movement of turbines attracts the eye and reduces the experience of tranquility and peacefulness. The rotating wings of the turbine reflect the sun creating flickers of light and cast shadows (shadow-flicker) which adds to the nuisance sense of movement.

Then there is the noise. Like any piece of equipment containing moving parts, a wind turbine emits a certain amount of mechanical noise. As wind turbines tend to be installed in quiet rural areas where people often chose to live to escape man-made noise – it can be a source of constant stress. 14

Danger to Wildlife

Wind farms have an adverse impact on wildlife, particularly on birds and bats which have a high collision rate with turbines. 15 A substantial majority of the bird fatalities in North America for example, are small songbirds which are a migratory species. (Baerwald and Barclay 2011; Jain et al. 2011)

Marine Life & Fisheries

Marine fisheries are concerned that building artificial structures in our oceans could cause irreversible damage to the natural biodiversity of those waters. Water currents may be disrupted, which interferes with the natural feed flows for fish, leading to alternations in the marine food web and famine for native species. At the same time, this leaves the door open for alien predatory species which could cause the die-off of native fish stocks.

The fisheries industry argues that while wind farms may create jobs, it is important not to destroy existing fishing jobs that allow coastal rural families and communities to thrive across the world. Our oceans are already under extreme stress as it is, from ocean deoxygenation, acidification and marine heatwaves, to overfishing and pollution.

On the positive side, wind turbine foundations may act as artificial coral reefs, providing a surface to which animals attach. As a result, there can be an increase in the number of shellfish, and the animals that feed on them. A second possible benefit is the sheltering effect. A safety buffer zone surrounding the wind turbines may become a de-facto marine reserve, as the exclusion of boats within this zone would reduce disturbance from shipping.

Disrupting Sea Beds

The installation of wind turbines can disrupt seabeds, and trigger the release of blue carbon and other potential toxic compounds. Blue carbon ecosystems, which includes seagrasses, mangroves and tidal salt marshes, store disproportionately large amounts of carbon dioxide (CO2). When they are disturbed, they release CO2 which contributes to rising temperatures. 

Unfortunately, as human development of coastlines has accelerated, these blue carbon ecosystems have been increasingly degraded or lost.

The Future: Pressure To Perform

The International Renewable Energy Agency (IRENA) recently issued a report, outlining specifically the growth in wind power deployments that would be needed in the next 3 decades to achieve the Paris climate goals. It showed that onshore installed wind capacity must increase 3-fold by 2030 and 9-fold by 2050, compared to 2018 . For offshore wind power, the global cumulative installed capacity would need to increase almost 10-fold by 2030 and continue on towards 2050. 16

It’s a tall order! Yet, progress in building new wind farms is consistently falling short of what is needed, and there is a growing gap between top down targets from governments and the private sector’s ability to build and invest at the right pace.

While, the cost of electricity generated from onshore wind continues to decrease – the global average falling to $53/MWh in 2019 – simply being more competitive on price, does not mean the transition to renewables will happen spontaneously, or that wind and solar power will replace fossil fuels within the needed time frame. 17

The problems are not just technical, but administrative and political. More than 10 GW of wind projects were stuck in permit delays in 2019. The largest barriers concern aviation and the military, with about 8 GW blocked due to proximity to air control radio masts and military restrictions.

Another factor is legal actions mounted by wildlife and nature groups, which affect 60 per cent of the 1 GW of approved capacity in the appeal phase.

As a result of these and other delays, the average duration of the permit process has nearly tripled since 2010. 4 Any easing of barriers for construction permits will require careful management with different stakeholder groups. Yet, the issue does require action, because when projects get stuck, developers and investors lose confidence.

Governments need to ensure that their markets are friendly to the expansion and investment in wind, solar and battery storage technology. It may be that we should be looking beyond measuring the success of renewables by cost per unit, and instead focus on system value. That is to say, the net sum of positive and negative impacts of an energy source on society as a whole. The polluters would be penalized by a carbon tax for example. Wind would be even more competitive if greenhouse gases were taxed, and in fact, it could push fossil fuel generation entirely off the grid.

Future of Renewables

The latest hope for renewable energy is Nuclear Fusion, an extremely expensive quest for limitless ‘always-on’ power that could theoretically revolutionize our energy system.

References

  1. Offshore Wind Outlook 2019 – IEA [][]
  2. BP Statistical Review of World Energy 2020 – October 2020.[]
  3. REN21-2019 Global Status Report Renewables; Paris [][]
  4. Global Wind Energy Council. Global Wind Report 2019; GWEC: Brussels, 2020 [][][][]
  5. Green Recovery Statement. Global Wind Energy Council 2020. PDF: https://gwec.net/wp-content/uploads/2020/06/Green-Recovery-Statement-EN-2.pdf []
  6. 2020 Global Electricity Review. Ember []
  7. “This Wind Farm in China Is Mostly Idle.” New York Times []
  8. “EU plans to increase offshore wind farm capacity 25-fold” – Guardian. Nov 2020.[]
  9. “Is wind power’s future in deep water?” Oct 2020 BBC []
  10. “To Get Wind Power You Need Oil” IEEE Spectrum 2016 []
  11. Evaluating the Environmental Impacts and Energy Performance of a Wind Farm System Utilizing the Life-Cycle Assessment Method: A Practical Case Study. Mohamed R. Gomaa, Hegazy Rezk et al. August 2019 []
  12. “Life Cycle Greenhouse Gas Emissions from Electricity Generation.”. NREL. PDF: https://www.nrel.gov/docs/fy13osti/57187.pdf []
  13. “The Vindication of Don Quixote: The Impact of Noise and Visual Pollution from Wind Turbines” Catherine Ulla Jensen. Nov 2014 []
  14. Guidance Note on Noise Assessment of Wind Turbine Operations at EPA Licensed Sites (NG3) PDF: www.epa.ie/pubs/advice/noise/Wind_Turbine_web.pdf []
  15. Wind Turbine Interactions with Wildlife and their Habitats. Energy.gov 2014. PDF: www.energy.gov/sites/prod/files/2015/03/f20/AWWI-Wind-Wildlife-Interactions-Factsheet.pdf []
  16. IRENA scenario for a 1.5-degree compliant pathway by 2030. []
  17. Renewables 2020 and forecast to 2025. IEA []
Share on facebook
Share on twitter
Share on linkedin
Share on whatsapp
Share on email