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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The 2013 IEA Technology Roadmap: Wind Energy details the actions governments could take to significantly reduce the cost of wind power and increase its share of energy contribution from its current 2.6% to 18% by 2050. More »»

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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.


Land-based wind power is a proven and mature RE technology that is being deployed globally on a mass scale. Wind turbines extract kinetic energy from moving air flow (wind) and convert it into electricity via an aerodynamic rotor, which is connected (often via a transmission system) to an electric generator. Today’s standard turbine has three blades rotating on a horizontal axis, upwind of the tower, with a synchronous or asynchronous generator connected to the grid using power electronics. Two-blade and direct-drive (without a gearbox) turbines are also available.

The electricity output of a turbine is roughly proportional to the rotor area; therefore, fewer, larger rotors (on taller towers) use the wind resource more efficiently than more numerous, smaller machines. The largest wind turbines today are 5-6 MW units, with a rotor diameter of up to 126 metres. Typical commercial wind turbines have a capacity between 1.5 MW and 3 MW.

Since 2000, cumulative installed capacity has grown at an average rate of 24% per year (%/yr). In 2012, about 45 GW of new wind power capacity were installed in more than 50 countries, bringing global onshore and offshore capacity to a total of 282 GW. New investment in wind energy in 2012 was USD 76.6 billion. Among the largest clean energy projects financed in 2012 were four offshore wind sites (216 megawatts [MW] to 400 MW) in the German, UK and Belgian waters of the North Sea, with investments of EUR 0.8 billion to EUR 1.6 billion (USD 1.1 billion to USD 2.1 billion).

Thriving markets exist where deployment conditions are right. Progress made since 2008 shows a positive trend: in 2012, wind power generated about 2.6% of global electricity while capacity and production information for wind resources around the globe show steady expansion.

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 generation and projection

IEA, (2013), Medium-Term Renewable Energy Market Report 2013, 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.


Offshore wind generation and projection

IEA, (2013), Medium-Term Renewable Energy Market Report 2013, 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.