Wind energy is a clean, renewable way of generating electricity (See close-up "Harnessing the Wind"). In the future, provided costs are reined in, the primary focus will be offshore development.
Cost and Intermittence
The pros and cons of wind powerIn physics, power is the amount of energy supplied by a system per unit time. In simpler terms, power can be viewed as energy output... are still the subject of heated debate. There are two main arguments against wind power:
- It is more expensive to produce wind-sourced electricityForm of energy resulting from the movement of charged particles (electrons) through a conductor... than electricity from conventional sources, such as nuclear and thermal energy. This means that wind power needs to be subsidized, mainly in the form of preferential feed-in tariffs.
- Wind power is intermittent because winds are unpredictable and uncontrollable. This may result in large swings in output and even shutdowns. However, grid operators are used to dealing with the problem of intermittenceInability of a renewable energy source to deliver a steady supply of electricity..., which is also an issue with other sources of energy, like solar. It is estimated that a large-scale grid can integrate a wind energyEnergy derived from the wind. Wind power involves converting the kinetic energy of moving air (wind) into electricity. penetration rate of 20% without experiencing major technical problems.
Other solutions are also being developed to address the problem of interrupted power supply. One answer is to set up interconnected groups of wind turbines over extended areas in order to leverage their combined energy and ensure a guaranteed minimum amount of power. Research is also being carried out on ways to store large quantities of surplus electricity, particularly through the use of batteries.
A Fast-Growing Industry
Despite these difficulties, wind power is rapidly developing in practically every part of the world, with growth rates ranging from 10 to 40% per year. Although the pace of growth slackened in 2013, installed global capacity reached an impressive 318 GW, for an increase of 200 GW in five years1.
The European Union is particularly well positioned, thanks to its assertive policy of developing renewable energies. In 2013, wind power accounted for 117 GW of installed capacityThe power generation capacity of a particular plant. It is usually expressed in megawatts (or sometimes even gigawatts)... in the E.U., meeting 8% of its electricity demand.2 The industry continues to grow despite a decrease in 2013.
Offshore, the Future of Wind Energy
The European Union 2007 roadmap for renewable energyEnergy sources that are naturally replenished so quickly that they can be considered inexhaustible on a human time scale... sources estimates that wind energy could account for 13% of the electricity consumed in the E.U. by 2020. A third of this electricity will probably be produced by facilities located offshore, where winds are stronger and more reliable.
Europe is focusing heavily on offshore development. Three countries — the United Kingdom, Denmark and Germany — are spearheading this drive. The European Wind Energy Association (EWEA) is projecting that offshore installed capacity will increase to 40 GW in 2020 from 6.5 GW in 2013.
Various options are being examined to improve the technology for installing wind turbines. At present, wind turbines are anchored to the seabed in water depths not exceeding 30 meters. Studies and tests are being conducted on artificial islands and wind turbines on floating foundations anchored at depths of up to 60 meters.
To reduce investment costs, researchers are also looking into the possibility of using existing offshore oilDescribes crude oil produced offshore, either in shallow water (depths up to 700 meters) using standard methods, or in deep water... platforms that are nearing the end of their useful life, something that holds out considerable potential. A project is under way to build 200 wind turbines in the Beatrice oil field, in water depths of 45 meters. Each turbine will be equipped with 60-meter blades built to withstand the North Sea winds.
Airborne Wind TurbinesScientists are racing to develop high-altitude wind turbines capable of harnessing stronger and more consistent winds higher in the atmosphere. Although different models are either in the design or testing stage, there are significant feasibility, and particularly, viability issues associated with their development. Laddermills, which are like giant kites, are composed of a series of kiteplanes on a long string that use wind energy at an altitude of 9,000 meters, where wind speed can be 20 times higher than at sea level. Other projects feature helium balloons or flying wing turbines.