Wind energy

Some orders of magnitude

wind energy comes in the beginning from the sun (to read the continuation), like all renewable energies (excluded geothermal energies and tidal). However, the Earth receives in 30 minutes the equivalent in solar energy of the yearly consumption of humanity, all types of energies confused. 1 to 2% of this energy coming from the sun is converted into wind, that is to say 50 to 100 times more than the energy converted into biomass by photosynthesis.

a wind mill of 2 MW feeds in electricity approximately 4000 people (except heating), that is to say an annual production from 4 to 5 million kWh.

In the first half of 2007, France has 2 GW of wind power installed, only with ground (there are no yet fields offshore oil rig). Germany has of it 20 GW, the USA and Spain 11 GW, India 6 GW and Denmark 3 GW.

In France, the wind potential is very important (the 2^e of Europe): 20 terrestrial GW for a production of 50 TWh per annum, and 40 offshore oil rig GW for a production of 150 TWh per annum. The theoretically exploitable wind potential is thus of 200 TWh per annum, that is to say about half of French consumption of electricity (450 TWh in 2006).

This production of 200 TWh/an would represent: for the offshore oil rig, 40 large wind power stations installed between 15 and 40 km of the coast, with maximum depths of 200 m; for the terrestrial sites, 10.000 wind mills, is less quarter of the number of pylons very high voltage (400 Kv) installed in France (which measure 50 to 55 m in height - and up to 100 m in the undulating zones, against 70 to 100 m for the masts of the large wind mills).

Current location of technology

A little history

During centuries, wind energy was used to provide a mechanical work. The most known example is the Windmill used by the Meunier for the transformation of the Blé into Farine, one can also quote the many windmills being used for the draining of the Polders in Holland.

Thereafter, during several decades, wind energy was used to produce electrical energy in moved back places and thus not-connected to an electrical communication. Installations without Stockage of energy implied that the energy need and the presence of wind energy are simultaneous. The control of the Stockage of energy by batteries made it possible to store this energy and thus to use it without presence of wind, this type of installation relating to only domestic needs, not applied to industry.

Since the Nineties, the improvement of the technology of the wind made it possible to build aerogenerators of more than 1 MW. These units were democratized and one finds some today in several countries. These wind mills are used today to produce alternative course for the electrical communications, as well as a Nuclear reactor, a hydro-electric Barrage or a Thermo plant with coal. However, the powers generated and the environmental impacts are not the same ones.

Comparative of the producing installations of electricity

(figures of 2006)

an aerogenerator: of a few kw until 5 MW (the majority of the large wind mills installed today in France have a power from 1 to 3 MW)
a solar power station Photovoltaïque: of a few hundred Watts to 10 MW (record: solar power station Bavaria solarpark in Germany, last from 10 to 12 MW in 2006)
a thermodynamic solar power station: from 2 to 60 MW (record: 80 MW in the desert of Mojave, the USA)
an hydroelectric station: of a few kw to 3000 MW (record: 32 turbines of 700 MW is 22400 MW with the Barrage of the Three Throats in China, to see the bond at the end of the page)
a Nuclear reactor: about 900 to 1300 MW in general (record: 1550 MW with the nuclear plant of Civaux in the south of Poitiers).

However the comparison of power between techniques of electrical production as different as the nuclear power, the solar one or the wind one brings only limited information since with power equalizes their annual electrical productions are strongly different.

A nuclear section of 1000 MW electric output can deliver, in the absence of incident and within the framework of an operation in base, approximately 8.000.000 MWh per annum. The nuclear plants functioning in base reach load factors higher than 95%. In France, the nuclear plants make follow-up of load (the delivered power adapts to the fluctuations of the request of the network) and have load factors of about 80%, corresponding to an annual production of 7.000.000 MWh per section of 1000 MW electric. The figure retained for wind European installed is of 2.000 MWh of annual production per MW of working installed capacity, that is to say a load factor from approximately 23% (2.000 hours operation of equivalent full mode per annum). The solar photovoltaic one produced between 1.000 and 1.200 MWh per MW of installed capacity working in France. This production varies according to the output of the installations (those of before year 2000 were of 10% whereas the news makes 15% rather) and according to the sunning of the place. The annual figures of photovoltaic solar production announced by various countries show extreme cases: in Germany they are of 574 MWh per MW, and in California of 1.458 MWh per MW.

Wind energy utilization in isolated site

Wind energy is also used to provide energy to isolated sites, for example to produce electricity in the islands, for the pumping of water in fields, or to feed in electricity of the sailing ships, headlights and beacons. These wind mills of small power are known as to belong to the wind Petit, in opposition to the large wind one or with the wind industrialist.

Wind energy in the French electrical communication

The manager of the French electrical communication (RTE), estimates that the integration of wind electricity in the current network is possible without major difficulties to a total value of 10 to 15 GW, in particular thanks to the presence in France of 3 independent layers of wind, which will allow a smoothing of the production much better than in Germany or in Denmark.

The wind mills connected to the electrical communication are generally gathered in a Wind farm from approximately 5 to 50 machines, but there exist also isolated machines. One also notes the existence of a project, not yet carried out, aiming at integrating wind mills of the type Darrieus in the electric pylons: the project Wind' It.

RTE (Grid system of Electricity), a subsidiary company of EDF, conveys the electric current through the network. This electric current must have a frequency of 50 Hz (in France as in many countries throughout the world, to see article: Electrical communication).

A wind mill connected to the network must thus provide this frequency, whatever the speed of the wind. This constant frequency passes by a number of constant revolutions of the blades. The latter is obtained by regulation in particular with the orientation of the blades.

If the speed of the wind is too low (for example less than 10 km/h), the wind mill stops because of the forces of solid friction which are opposed to the rotation of the propeller. This reduction number of revolutions does not make it possible any more to provide this frequency. In this case, the wind mill is not thus producing any more of electricity, but could on the contrary become consuming, it is thus necessary to disconnect it.

If the speed of the wind is too strong (higher than 100 km/h for example), the wind mill is put in safety and disconnected from the network, its blades are put in flag and stop to avoid requests which could break them.

The French law obliges EDF to buy the current produced by the wind mills or any other system of production of electricity. In addition, the tariff of purchase of wind energy is improved (except for the wind mills of more than 12 MW), to support this young die under development full and to make it possible France to achieve the goals of the European directive.

Features

The energy Rendement (just as the Power developed) of the wind mills is function the speed of the wind to the cube. Thus the currently marketed wind mills need a wind in the range of 11 with 90 km/h (3 with 25 m/s). The future wind mills, whose first prototypes are put in servicing 2006, accept winds of less than 4 with more than 200 km/h (1 to 60 m/s). Like the solar energy and others renewable energies, the wind one needs either an auxiliary energy for the less been windy periods, or of means of storage of produced energy (batteries, hydraulic storage or more recently, hydrogen).

Worldwide economy of wind energy

Thousands of wind mills function at present in various areas of the world, with a full capacity of more than 73 900 MW, and the Europe takes part in 65 there; % (fine 2006). In this total some private companies connected or not to the network are not entered.

The Germany is the principal producer of wind electricity with 20622 MW of installed capacity working with the end of the year 2006. The Spain is the second world producer with 11615 MW. At the end of 2006, the the United States had an installed capacity working of 11603 MW, in third position behind Germany and Spain. France was in 2006 the 10th energy producer wind mill in Europe with 1567 MW (WWEA 2006).

As comparison, the installed capacity working in nuclear energy is of 21000 MW in Germany, 63000 MW in France and 98000 MW in the United States (figures of 2003)

The figures above must be balanced by taking account of a load factor , i.e. production and operation life of the equipment in one year. For the wind one, the load factor is of with more than 20%. For example for Germany it is only of 16% in 2005, against a load factor of more than 80% for a power station nucléaire.
One can observe moreover than the load factor decreases with the increase in the park of wind mills, direct consequence of the exploitation of less and less been windy sites.

According to the Observatory of Renewable energies, in a report published by EDF, the wind one is currently the energy die most dynamic in the world and more particularly in the European Union where the wind electrical production increased by 37.8% per annum on average of 1993 until 2002. This growth reached 59% per annum over the same period for France, which was largely late in this field. According to the same source, for the years 2003-2004, the growth in the European Union remains constant with an annual rate of 28,9% (42,9% in France) over these two years, and accounts for from now on 12,4% of the production of ENR of the EU, on the way of détroner the production starting from biomass (production: 12,9%, growth: 10,8%) like 2nd electric source of origin ENR after hydraulics (production: 73,3%, null growth).

New wind farms at sea (wind offshore oil rig) are considered everywhere in the world. The Denmark is one of the most important actors, with its laboratory Risø, very famous; the country produces approximately 20 % of its electricity with wind mills. The wind mills produce 1 % of the production of electricity in the world. The most profitable size and most practical for the currently marketed wind mills seems to be around 600 kw with 2 MW, grouped in large wind farms. New technologies under development seek to produce systems much more flexible in term of " power rentable". The majority of the terrestrial wind mills function with a load factor of 25% per year, but some arrive at 35%.

the Germany, world leader in this die, continues since 1999 to install an average of 2 GW of additional power per annum.

the Spain, since 2002, adopted the rate/rhythm of Germany and develops its working installed capacity of approximately 2 GW per annum also.

With the the United States, of the studies recommends gigantic projects, but let us associatons them ecologists are opposed and multiplied the legal actions to it. (see bond)

the Denmark, almost stopped the development of its installations since 2003; it is at the stage of a saving in replacement. The wind electrical production in this country appreciably accounts for 20% of its consumption of electricity. This level, it is not possible in the actual position of knowledge and the techniques of going further because of the unforeseeable variability of the wind electrical production in direct injection on the network. Research is in hand to store part of the production in the form of hydrogen for example. This research aims to be able one day to exceed this limit of the 20% (Spanish site of search for Sotavento with Montféra).

the China, which remains in 2005 the 3rd larger electric energy producer behind the United States (4.239 TWh) and Europe (3.193 TWh) with 2.500 TWh produced (International agency source of Energy), should be the 5th world producer of wind energy in 2007 behind Germany, Spain, the United States and India. Its objective is a wind power installed of 20 GW in 2020, is an increase of more than 1 GW per annum. This effort is despite everything extremely modest when it is seen that its electrical production increased by 860 TWh in 3 years (1.640 TWh in 2002). This growth of 860.000 GWh in 3 years which was done essentially by a multiplication of coal centres is without common measurement with the progression programmed of the wind one. This country recently stated (10.02.2007) not to have the means of passing to clean energies (see bond).

the the United Kingdom which sees its oil resources of the North Sea quickly decreasing year after year, decided to exploit as soon as possible its wind layer which is most important of Europe. Several projects in progress are most important in the world in the current location.

With the Canada, the electrical production by the wind is in increase, especially in the Prairies and with the Quebec. In this last province, the company of state Hydro-Quebec buys already 200 GWh with private producers of the area Gaspésie. The federal government announced an inciting program which should carry the working installed capacity to 10 GW by the end of 2015 (Canadian source ACEE).

The wind one in Europe

Wind production capacity electric deployed in Europe increased by 154% between 2000 and the beginning of 2006, which constitutes more half of the new production capacities installed during this period).

The wind one in France

According to EDF Among renewable energies, the wind one has more the strong potential of development and will represent a majority share in the production of renewable energies except hydraulics. The wind one will thus contribute its share to the energy independence of France .

With the beginning of the year 2005, the French wind farm counted 629 wind mills. France with its DOM produced 386 MW what represented less than 1% of its total electricity consumption.

Second wind layer of Europe (wind resources) after the United Kingdom, France currently tries to fill the delay accumulated in its exploitation. The obligation of EDF in the purchase of electricity of wind origin makes the investments wind profitable. The park installed in March 2006 reaches 1000 MW but the objectives posted for the wind one are of 10.000 MW in 2010 (6000 to 9000 wind mills).
The first producing area remains the Languedoc-Roussillon (17 parks and 64 machines for 162 MW), followed by the Brittany (125 MW), Champagne the Ardennes (81 MW), Picardy (71 MW), the Rhone-Alps (68 MW), Lorraine (65MW), the Nord-Pas-de-Calais (63 MW). By the creation of 8 new parks producing 170,2 MW, Languedoc-Roussillon increases its potential during the time 2005 - 2007 and should remain the first producing area in France.
Areas like Aquitaine, Burgundy, the Franche-Comté and Alsace did not carry out on this date any establishment.

To refer to the very documented report/ratio of Jerome GOSSET and Thierry RANCHIN: ''' Assessment and futurology of the French wind die ''' - CONTRACT ARMINES/ADEME n° 50722 of February 10th, 2006.

The industry of wind energy evolving/moving very quickly, it is useful to note that today the figures above are not any more of topicality. As example, at the beginning of 2007, the Région Centers with a capacity of 260 MW, including 77 wind mills located in the only department of Eure-et-Loir.

The wind one in the Champagne-Ardennes

See also: Wind energy in the Champagne-Ardennes

The wind one in Quebec

The energy policy of the Quebec envisages the development of wind projects adding up 4.000 MW from here 2013. The development of the wind potential of Quebec is done primarily by the recourse to the private companies which are requested via a system of invitations to tender. Several groups claim rather than the Company of state Hydro-Quebec develops itself its own wind projects and than it remains owner of the means of electrical production, as it is the case with the great majority of the hydroelectric stations of the province.

Future of wind energy

Technology

The rise of the price of the fossil energies returned research in the field of wind more attracting for the investors.

Technology currently the most used to collect wind energy consists in placing at the end of a horizontal axis of the Pale S forming a Hélice. Certain prototypes use a vertical axis of rotation.

Technology with horizontal axis presents certain disadvantages:

the obstruction space is important, it corresponds to a sphere of a diameter equal to that of the propeller, resting on a of the same cylinder diameter. A mast important height is necessary to collect a wind more the extremely possible.
the wind must be most regular possible, and thus prohibited of the establishments in urban environment or in a very broken relief.
a blade of 40 meters which would describe a rotation a second would see its end advancing at a speed of 250 m/s, that is to say approximately 900 km/h. It is the reason which explains the wind noise of pale and one of the reasons of the setting in stopping of the wind mills by strong wind. In practice the blades of the large wind mills never exceed a speed of about 100 m/s at their end. In fact, plus the wind mill is large, and less the rotor turns quickly (less than 10 turns/minute for the large wind mills offshore oil rig).
the energy production depends directly on the force of the wind, independently of the needs, it is thus necessary to take into account the evolution day laborer or seasonal of the load diagram, even the storage of produced energy.

The new wind mills under development make it possible to lead to a technology which is freed from the noise, the obstruction and the brittleness of the blade wind mills, while being able to use the wind whatever its direction and its force. Many alternatives are studied by live tests in life size. Certain wind mills are of small size (3 to 8 meters broad, 1 to 2 meters in height), with for objective of being able to install them on the roofs terraces of the residential buildings in the cities, or on the roofs of the industrial and commercial buildings, in ranges of powers going from a few kw to a few tens of kw of average power. Their number of revolutions is weak and independent the speed of the wind. Their power varies linearly with the speed of the wind, which can vary from 5 km/h to more than 200 km/h, without requiring celebrates it " setting in drapeau" blade wind mills.

Storage

With large scales one of the best means of storing electricity is the hydroelectric energy. STEP (stations of transfer of energy per pumping) are constituted of basin lower and of upstream reservoir (natural or artificial), which makes it possible to store energy (for example of electricity wind or nuclear) during the basic periods consumption by pumping lower basin towards the upstream reservoir, and to restore it during the periods of strong demand while making forward by a turbine the water of the upstream reservoir towards the lower basin. The STEP are of the interest to be able to store very great quantities of energy (until several hundreds of GWh, that is to say the equivalent of several hundred operating hours of a nuclear reactor), with an excellent output (80 to 85%), and to start itself very quickly (in a few minutes). In France the largest STEP is the dam Grand' Maison, with a maximum power of 1800 MW (equivalent to 2 nuclear reactors).

A track is the electrolysis of the Eau and the production of Hydrogène, which can be stored before being reconverted in energy according to the needs by means of a Combustible battery, producing electricity and heat. The total output of this cycle of energy production is still too weak at present to return interesting the storage of energy by hydrogen. Technologies related to hydrogen require progress, mainly of manufacturing costs and maintenance, before being able to pass at an industrial stage. The first combustible batteries connected on distribution networks electric were brought into service in the Années 1990.

In the United States, a company designs new wind mills who produce Compressed air instead of electricity. In the nacelle of the wind mills instead of an alternator thus a compressor of air is. The compressed air is stored and makes it possible to make turn an alternator at the times when the needs are felt more. Storage makes it possible not to more inject on line electricity on the network with the wire of the wind. From the point of view of the storage of energy, this way of doing also makes it possible to save 1 energy transformation. With storage in the form of hydrogen for example, there are 2 conversions: electricity out of hydrogen, then hydrogen in electricity. Here, there is only one of them: compressed air in electricity. From where an economy on the losses on translation due to storage/destocking. Even if this only conversion still involves losses, they are compensated by a more interesting selling price of electricity than one can produce at the time of the strong demands, where the prices are definitely higher. The production of wind electricity at the only times of peak demand could also make it possible not to more oversize electric production capacities currently intended to be able to pass in safety the maxima of consumption. Some even think that one could directly use the compressed air thus produced to feed from the motor vehicles propelled with this fluid.

The wind offshore oil rig

The installation of firm wind mills offshore oil rig is one of the ways of development of the wind one, because it is freed mainly from the problem of the esthetic harmful effects and vicinity, in addition the wind is much stronger and constant that with ground. This solution very allows the progressive technical development of wind mills of great power.

Thus, the wind electrical production at sea is more important than with ground at equivalent power. One usually gives like average 2.500 MWh per MW installed at sea instead of 2.000 MWh per MW installed to ground. In the maritime zones geographically very favorable to wind, the estimates of the studies indicate the potential of cases extrèmes of 3.800 MWh per MW installed.

Various solutions are planned to reduce the cost of produced kWh. Among the studied solutions, one can note:

the construction of wind mills moreover great power, producing from 5 to 10 MW per unit;
the development of floating systems, anchored, allowing to free itself from the costs of the foundations of pylons to great depth.

The projects of the future wind mills offshore oil rig, to the horizon 2010, aim at a unit power of 10 MW, with a diameter of blades of 160 meters.

An option making it possible to reduce the capital cost to kw installed could be in the long term to couple on the same pylon an offshore oil rig wind mill and one or more Hydrolienne S.

In France, the Company of the wind announced in November 2006 its project of park of the Two Coasts, a whole of 156 wind mills adding up 702 MW, to 14 km off the Seine-Maritime and of Picardy. In England, the consortium London Array has a project to 20 km of the mouth of the Thames, which would represent 271 turbines for a power going up to 1.000 MW. With the additional project of Thanet, these is now 1800 MW which should be installed in the estuary of the Thames. The Britannique project of Triston Knol will make as for him 1.200 MW.

A concept even more innovating is developed by the Norwegian company Norsk Hydro (specialized in the oil and gas exploitation offshore oil rig): it consists in creating fields of floating wind mills, by 200 to 700 m basic. The principle is to use a floating concrete box (anchored to the bottom by means of cables) to support the wind mill. This project would revolutionize the wind offshore oil rig, because it would make it possible to worry the depth more, and thus to install giant fields (up to 1 GW of working installed capacity) far from the coasts. That would in addition make it possible to reduce the price of the wind fields offshore oil rig, by avoiding the construction of expensive underwater foundations.

The wind urban one

The wind urban one is a concept which supposes that one can install and exploit wind mills in urban environment. The wind urban one seeks compact wind turbines able to propose a decentralized electrical production, which would be freed from transport and the generated losses.

The existing wind turbines never yet reached interesting outputs in urban environment. However, the originators already developed prototypes on which there are no more blades like those of a propeller, but a rotor fixed at its two ends, equipped with blades to get a constant couple whatever their position compared to the axis of the wind. In certain projects is added to the rotor an external stator, fixed element intended to deviate the race of the wind in order to optimize the output of the unit. The mechanical design of the wind turbines makes them resistant to the strong winds, and frees them from the need to be stopped when the wind exceeds the speed of 90 km/h. Their production is almost proportional to the speed of the wind until more than 200 km/h, without stage limiting as on the traditional wind mills.

Projection of the wind and nuclear world productions electric

Since ten years, the world wind electrical production doubles every three years roughly:

1997 : 8 GW/16 TWh
2000: 18 GW/36 TWh
2003: 39 GW/78 TWh
2006: 74 GW/148 TWh

by continuing this tendency one obtains:

2009 : 150 GW/300 TWh
2012: 300 GW/600 TWh
2015: 600 GW/1.200 TWh
2018: 1.200 GW/2.400 TWh
2019: 1.560 GW/3.120 TWh (growth of 30% in one year)

The world nuclear electrical production reaches a maximum around 2.700 - 2.800 TWh. This production seems to have to go up slightly in the decade which comes because of political volunteers. But the growth should be moderate, because n the other hand, of many power stations arrive at the end of the lifetime.

Under these conditions, and provided these tendencies do not change, the electrical productions world wind mill and nuclear power could make good match from here a dozen years.

Discusses on wind energy

There exists a polemic, which date of the origination of the windmill, and relates on the various harmful effects (visual, sound, etc) and to the interests (economic, uses, etc) of wind energy.

Reference mark

the wind offshore oil rig would be a solution to reduce the problem of intermittency of the wind, and thus of the electrical production.
the other axes of anticipated progress are it mix-energetics (wind, solar, geothermics) and the progress of the storage of energy.
the most advanced countries in the development of wind (Germany, Denmark, etc) solve the problems of the intermittency with in particular thermics but also the purchase of electricity produced by other countries.
projections of the " trend energy Scenario at 2030 for France - DGEMP-OE (2004) - synthesis of the work completed in 2004 by the Observatory of the energy of the Head office of energy and the raw materials " misent on a wind potential of 43 TWh in 2030, that is to say 11% of the nuclear production on this date, with a potential installed of 19 GW into wind, of 50 GW in nuclear power, for a total of 144 GW of output capacity installed.
Denmark ceased building wind mills since 2005, why?
Holland stopped any form of subsidy to wind also.
the German network of transport/distribution of electricity is at the edge of the rupture and must stop the arrival of wind energy the days of high wind because the problem of the intermittency of the wind is not and will not be solved by " the off-shore" because this last is subjected to the same regional climatic conditions as the " terrestre".
Per day of nominal wind, wind Danish cannot run out his current differently than… to dissipate it by electrical resistances in the ordinary boilers of thermo plants, dividing by 3 its effect anti-CO2. It is the only means of making saving in CO2, to spend a expensive calorie to manufacture 1/3 for the same price of them. Wasting.
to avoid this wasting, it is necessary that this random energy is used by customers who accept a random supply (back up heater) at price with most equal to that of gas/increased fuel of the loss which had with the output of the boiler (1/80% = x1.25).
It is necessary for us thus to modify our practices of life to allow the effective use of random but powerful soft energy. It is a turn of civilization which will bring us closer to Nature.

External bonds

Guided Turn one Wind Energy. A Danish Internet site (in English) making a very complete review on wind energy: wind, turbines, costs, network connections, environment…
Legislative framework in France concerning the installation of wind mills (file pdf)
The Wind Power Database on the wind fields and the wind mills.
wind Planet. A site of reference on the wind one in France.
wind of anger. A very complete site on the disadvantages of the wind mills.

References

Beats-smg: Viejė energėjė Be-X-old: Энергіяветру

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