ABOUT WIND POWER

WHY?

Scarcity of fossil fuels and global warming
Fossil fuels, at the origin of an unprecedented prosperity over the last two centuries, are becoming more and more rare. If the increase in energy consumption continues at the same rate as today, the crude oil reserves will have dried up by 2050 and natural gas will follow shortly afterwards. Only coal could last for the next couple of centuries. These fossil fuels provide 85% of world energy. They are also mainly responsible for global warming.

Without drastic and immediate measures, the accumulation of carbon dioxide that they emit after combustion will have dramatic consequences for the future of mankind. This problem has forced the international community to implement a new model of sustainable development based on reinforcing energy efficiency together with the massive development of renewable energies.

Europe's choice in favour of renewable energies

The European Council adopted, in March 2007, a strategy "for safe, competitive and sustainable energy" known as the "3 x 20 roadmap". It has three major aims for Europe between now and 2020:
• To reduce greenhouse gas emissions by 20%;
• To improve energy efficiency by 20%;
• To boost the share of renewables in the total energy consumption to 20% (compared to 10% for Europe today).

Ever since, Europe does everything to develop this strategy and to increase the share of renewable energies in its electricity production.  At the end of 2009, 75 000 MW of wind energy are installed in Europe totaling an annual production of 142 million MWh, which represents 4.2% of the total European electricity consumption.

Wind power thus becomes the first source of electricity production in terms of newly installed capacity in 2009. Moreover it has registered significant growth, of about 30% per year for the last ten years.

At a worldwide level wind energy represents 340 million MWh (out of which 100 000 MW installed in 2008) which represents 2% of the global electricity consumption.

At a national level, according to Grenelle's estimations, the French wind farms (park) will generate 55 million MWh, which represents 10% of the total national electricity consumption from now until 2020.



The political development strategy for wind power in France

The government supports the development of wind power by purchasing the kilowatt-hours at a set tariff. This policy corresponds to a will to promote clean energy, in opposition to traditional forms of power production whose costs on the environment are outsourced. The fixed tariff also aims to guarantee wind developers' investments and to ensure the profitability of wind farms. This system has existed since 1955 for hydroelectricity. Fixed within the framework of a 15 year contract (20 years for offshore farms), the tariff is currently:

• 8,2 ct€/kWh for 10 years for onshore wind farms and then between 2,8 and 8,2 c€/kWh for 5 years depending on the quality of the wind on site,
• 13 ct€/kWh for 10 years for offshore wind farms and then between 3 and 13 c€/kWh for 10 years depending on the quality of the wind on site

In spite of all the rumors about the cost of renewable energies, it must be said that the contribution to the wind energy costs represents only 1.50 € per home and per year so, it is obvious that in the years to come, the first wind farms will no longer benefit from the set purchase tariff fixed to a 15 year period.
André Antolini, President of the Renewable Energies Association underlines that: "The electricity that the wind farms generate, will actually be purchased at a lower tariff than the reference tariff as it will essentially finance maintenance costs; whereas the wind is free, local and inexhaustible".

Wind Development Zones (ZDE)
In order to define wind farm development in France, the Government recently created the concept of "wind development zones" (Zones de Développement Eoliens). Since July 15th 2007, only wind turbines erected in wind development zones are allegeable for the fixed tariff. The creation of these zones is instigated by local communities or groups of communities. The zones are then defined by the Préfet of the county, who establishes their geographical perimeter as well as the minimum and maximum wind capacity that can be installed. The administrative authorities then have six months in which to make a decision and proceed with the official creation of the ZDE.

The « Grenelle de l'Environnement »
The « Grenelle de l'Environnement », instigated in 2007 by the Ministry for Ecology and Sustainable Development, aimed at creating favourable conditions for the emergence of this new French force in favour of the environment. It united for the first time government bodies and representatives of civil companies in order to define a roadmap in favour of ecology, development and sustainable national planning. The Renewable Energies Syndicate (www.enr.fr/) played an important part in the debates and the conclusion is very positive for the future of renewable energies.

The objectives of the Grenelle de l'Environnement by 2020 are the following:

• +20% million tons of oil equivalent in renewable energies, which represents at least a 20% share of renewable energies in the national electricity consumption
  at the horizon of 2020.
• Wind energy is essential to reach this ambitious objective: it represents the equivalent of ¼ out of 20 million tons of oil equivalent (consumption).
• For the wind industry: 25 000 MW of wind energy, out of which 6 000 offshore MW, that represents the equivalent of 8 000 wind turbines.

In his closing speech, Nicolas Sarkozy declared: "a nuclear program was launched in 1974 to reduce our energy dependence. I want to launch a national program of renewable energies with the same ambition…"

A renewable, environmental friendly energy
Wind energy does not consume any fuel, releases no greenhouse gases and does not produce any waste. It uses wind, both abundant and inexhaustible. Its environmental impact is particularly limited. Technical progress has made new wind turbines increasingly quiet. There's nothing simpler than visiting a site to judge for yourself. Wind farms are open to all, with no boundaries, which testifies to the high safety level of the turbines. And they are often tourist assets for the villages where they are built. The appearance of wind turbines in the landscape is appreciated like an aesthetic symbol of sustainable development, preserving the future of generations to come.

In France, the construction of wind farms is subjected to one of the strictest legislations in Europe. A construction permit is necessary for the construction of a wind farm. This authorization is delivered by the Préfet of the county, taking into consideration an extensive impact study and a local public enquiry. The subsequent permit enquiry takes into account the opinion of the qualified state services, especially concerning the quality of the farm's integration into the surrounding countryside, protection of local fauna and flora, respect of any eventual archaeological remains, taking into consideration the peace of residents or guaranteeing the absence of any radio-frequency disturbances.

Wind energy is also a reversible source of energy production: the dismantling of a wind farm is simple and fast. And it leaves no trace. The law requires wind farm owners to set aside the cost of dismantling.

An accepted form of energy

The survey published by the General Commissioner of Sustainable Development in November 2010, states that wind energy is largely accepted by the French people. According to the Renewable Energies Association two out of three French people are favorable to the implantation of wind farms near their homes.

According to the poll conducted by the Renewable Energy Association, we notice that: "the general opinion on wind energy is rather positive. Moreover, it turns out that 67% of those who were questioned are favorable to installing wind turbines near their homes, (1 km distance). This opinion is shared by (almost) all the population strata".
The evaluation report of the "Grenelle de l'Environnement" presented by Jean-Louis BORLOO in November 2010 underlines the fact that at the end of 2010 "wind energy reached a total installed capacity of more than 5 000 MW contributing thus to more than 10% of the renewable energy production, hydraulic energy included."

Moreover the renewable energy sector is constantly developing, and it generates economic benefits as well as new green jobs. This currently represents more than 10 000 jobs; there will be 60 000 in 2020 when the total installed capacity will reach 25 000 MW and will represent more than 50% of the electricity of renewable origin in our country", explains Nicolas WOLFF, President of the France Wind Energy, the wind subsidiary of the Renewable Energy Association.

Wind Energy in numbers*:

• 5 000 MW of installed capacity throughout the national territory
  
• Approximately 3000 wind turbines
  
• 7.8 Terawatt-hours of electricity in 2009
  
• Approximately 11 000 jobs
  
• 2.31 million tons of CO² avoided in 2009

*Key numbers on the national territory concerning the evolution of the French Wind Industry until the 15/07/2010, according to the Renewable Energy Association

HOW?

Image courtesy of Siemens ©

A wind turbine is made up of three main parts: the tower, the nacelle and the rotor.

The rotor is the part which turns with the wind. It is made up of a hub, a propeller with 3 blades and a revolving axis inside the nacelle. Nowadays, the blades are made of composite materials which are both light and resistant: carbon or reinforced polyester glass fibre. Their length can currently reach anything between 30 and 55 metres, meaning the diameter of the rotor is between 60 and 110 metres. Why such dimensions? The power of a wind turbine is proportional to the surface swept by its blades (a disc). By increasing the length of the blades, the swept surface is increased and so is the power of the turbine.

Inside the nacelle is all the equipment which goes to produce electricity, from the rotation of the axis of the rotor, also known as the low-speed shaft. The rotation, caused solely by the wind, is transmitted by the low-speed shaft to a gear box where the number of revolutions is increased to 1500 rpm. This mechanical energy is then converted into electricity at 690 volts by a generator. A transformer, located in the nacelle or at the foot of mast, then increases this voltage to 20.000 volts and the electricity is then fed to grid via a substation.
In order to start, a wind turbine needs a minimal wind speed of 10 to 15 km/h. From 90 km/h upwards, the rotor stops turning automatically. If the wind turbine were to function in these conditions, the exertion would lead to premature wear. Such high winds are rare; stoppages due to strong wind do not therefore have a too negative incidence on the overall production of electricity.
The wind turbines are controlled by a computerized supervision system which in particular makes it possible to direct the turbine rotor and to modify the blade angle depending on the wind direction, in order to maximize energy production. Thanks to this system of supervision and control, the turbines can be stopped automatically and very quickly in the event of need. The safety of the wind farm is thus ensured non-stop.

The tower supports the nacelle and the rotor and is made up of several metallic sections, fixed to the ground on a concrete foundation which can be up 12 metres in diameter. However, once the construction works are finished only the tower is visible. The rest of the foundation is covered with earth and the area can be used for pastures or crops for example.
The wind turbine towers can be up to 100 m high for the more powerful turbines. The rotors are placed very high up because the wind is stronger than at ground level (and therefore more energy is produced) and is also less turbulent due to the lack of obstacles: hills, trees or houses.