Wind energy is developing towards a mainstream, competitive and reliable power technology. Globally, progress continues to be strong, with more active countries and players, and increasing annual installed capacity and investments. Technology improvements have continuously reduced energy costs, especially on land. The industry has overcome supply bottlenecks and expanded supply chains.

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About wind energy


Wind energy is kinetic energy of wind exploited for electricity generation in wind turbines.


Wind energy, like other power technologies based on renewable resources, is widely available throughout the world and can contribute to reduced energy import dependence. As it entails no fuel price risk or constraints, it also improves security of supply. Wind power will enhance energy diversity (unless it is already the dominant source) and hedges against price volatility of fossil fuels, thus stabilising costs of electricity generation in the long term. Wind power entails no direct greenhouse gas (GHG) emissions and does not emit other pollutants (such as oxides of sulphur and nitrogen); additionally, it consumes no water. As local air pollution and extensive use of fresh water for cooling of thermal power plants are becoming serious concerns in hot or dry regions, these benefits of wind become increasingly important.

About land-based wind


Land-based wind refers to the energy generated by wind turbines deployed in the mainland.

Onshore wind is a proven, mature technology with an extensive global supply chain. In some countries, onshore wind is also referred to as land-based wind, mainly installations that are located inland, far from the shore. The onshore technology has evolved over the last five years to maximise electricity produced per megawatt capacity installed. Machines have become bigger with taller hub heights, larger rotor diameters and in some cases bigger generators depending on the wind and sitespecific conditions.

Currently manufacturers offer utility-scale turbines with rotor diameters ranging from 50 m to 125 m, generators from 1.5 MW to 3.5 MW and hub heights from 90 m to 150 m. In addition, some manufacturers have started to offer 4-5 MW platforms over the last year. Meanwhile, the largest generator capacity of a single installed onshore wind turbine reached 7.5 MW.

Over the last year (2014-2015), it is estimated that wind turbine prices decreased 3-5% to around USD 1 050/kW for high-speed turbines and USD 1 175/kW for low- to medium-speed turbines.

Onshore wind leads the global renewable growth, accounting for over one-third of the renewable capacity and generation increase in 2015.

Repowering, i.e. replacing “old” wind turbines with more modern and productive equipment, is on the rise. Repowering is shown to increase wind power while reducing its footprint. A 2 MW wind turbine with an 80 metre (m) diameter rotor now generates four to six times more electricity than a 500 kW 40 m diameter rotor built in 1995.


Onshore wind annual additions by region (main case) versus accelerated case annual additions


IEA, (2015), Medium-Term Renewable Energy Market Report 2015, OECD/IEA, Paris.

About offshore wind


Offshore wind energy refers to the energy generated by wind turbine deployed in the sea. Depending on the depth of the sea, this area can be several tens of kilometres off the shoreline.


Deploying turbines in the sea takes advantage of better wind resources than at land-based sites. Offshore turbines, therefore, achieve significantly more full-load hours. Offshore wind farms can be located near large coastal demand centres, often avoiding long transmission lines to get power to demand, as can be the case for land-based renewable power installations – this can make offshore particularly attractive for countries with coastal demand areas and land-based resources located far inland, such as China, several European countries and the US. While needing to satisfy environmental stakeholders, offshore wind farms generally face less public opposition and, to date, less competition for space compared with developments on land. As a result, projects can be large, with 1 GW power plants likely to be achievable in the future.

Large-scale offshore deployment has started, more slowly than initially hoped, mostly in Europe. By the end of 2012, 5.4 GW had been installed (up from 1.5 GW in 2008), mainly in the United Kingdom (3 GW) and Denmark (1 GW), with large offshore wind power plants installed in Belgium, China, Germany, the Netherlands and Sweden. Additional offshore turbines are operating in Norway, Japan, Portugal and Korea, while new projects are planned in France and the United States. In the United Kingdom, 46 GW of offshore projects are registered, of which around 10 GW have been progressing to consenting, construction or operation.

In 2014, global offshore wind generated an estimated 25 TWh, 20% higher than in 2013. In 2014, global installed capacity of offshore wind reached over 8.8 GW, with 1.7 GW of new additions versus 2012.


Offshore wind generation forecast and projection

IEA, (2015), Medium-Term Renewable Energy Market Report 2015, OECD/IEA, Paris.

For more information please refer to the Technology Roadmap: Wind Energy - 2013 edition.

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Fast facts

  • 2.5%Percentage of global electricity demand provided by wind power
  • 2nd Onshore wind is the second-largest renewable electricity generation source.