Wind Energy: Electricity in the Air

  • Wind energy is a form of clean, sustainable and non-polluting energy. Its principle is simple: large blades, installed at the top of a mast, are connected to a horizontal axis, which begins to turn on itself when the wind drives the blades.
  • The horizontal axis is connected to a generator. When the wind blows, and the blades and their axis are moving, the rotation can produce electricity that is then stored in batteries (24 or 48 volts) until they are consumed.
  • Some models, thanks to a charge controller and wind inverters, can send electricity directly into the home network. Less conventional, but also less voluminous, vertical wind turbines (VAWT) have helical blades that rotate on the vertical axis of the mast.
  • Greenhouse gases such as CO2 (carbon dioxide) are produced by burning fossil fuels. These gases cause global warming, and this has effects on the climate on earth. Wind energy does not have those disadvantages.

How does wind originate?

After energy from biomass, wind energy is the most critical source of sustainable energy. Wind originates initially through the power of the sun. Solar radiation ensures that the air at the equator is heated up very strongly. At the North and South pole is hardly heated, because the solar radiation is very flat here.

Warm air rises upwards and flows towards the poles. When the air gets cold, it sinks down again, where it rises through the warm atmosphere of the equator rising upwards as it is sucked in by a vacuum cleaner.

  • Moreover, the earth's rotation also ensures that the hot air does not flow to the poles because due to earth rotation the air mass in the northern hemisphere is diverted to the right and in the southern hemisphere to the left. This phenomenon causes high and low-pressure areas.
  • The air movement from a high to a low-pressure area is called wind. In this way, this type of solar energy is also at the source of wind energy, just as the solar energy is also at the source of, for example, the energy stored in biomass. A wind turbine uses the power of the wind to drive an electric generator and thus generate electricity.

A wind turbine: how does it work?

  • A wind turbine has a way of converting wind energy into electrical energy: the large propellers of the wind turbines rotate thanks to the force of the wind, and the movement activates a mechanism creating electricity. The electricity is then injected into the electricity grid. A propeller is placed high where the wind speeds are higher.
  •  The propeller (also called rotor) is composed of 3 blades that turn more or less quickly, depending on the wind. At the top, the nacelle houses the mechanism that converts the rotation movements into electricity (the generator).

A wind turbine has a way of converting wind energy into electrical energy: the large propellers of the wind turbines rotate thanks to the force of the wind, and the movement activates a mechanism creating electricity. The electricity is then injected into the electricity grid.

A propeller is placed high where the wind speeds are higher. The propeller (also called rotor) is composed of 3 blades that turn more or less quickly, depending on the wind. At the top, the nacelle houses the mechanism that converts the rotation movements into electricity (the generator).

  • The current thus produced descends to the ground by cables located in the mast to be injected into the electrical network. Wind turbines are most often grouped to form "wind farms" or "farms". There are also offshore wind farms (offshore wind turbines) where the offshore wind can provide higher wind speeds, lower wind turbulence, and more consistent winds.

What are the advantages?

The greatest benefits relate to the environment. The process of generating wind energy does not release a harmful substance to the environment, as is done via non-renewable energies like coal and fossil fuel.

Wind is also inexhaustible, while fossil fuels are running out. Clean, sustainable and based on a free resource (the wind): wind energy at all to compete with photovoltaic solar panels regarding green energy.

A wind turbine gives the best of its potential when the winds are strong, that is to say in the heart of the winter when the needs for electricity increase. In well-winded regions, a wind turbine can allow a significant reduction in the electricity bill. In the case of surplus (when the energy produced is surplus to needs), it is possible to make a profit by selling it back to the energy supplier.

For separate buildings that are not connected to the grid, wind energy can provide independent power requirements. It also advantageously complements a system of photovoltaic solar panels and continues to produce electricity at night and in winter. 

What is wrong with wind turbines?

They are criticized for making noise, distorting the landscape, hindering the passage of migratory birds, disrupting fishing at sea, solving energy production problems, or problems with greenhouse gases.

Technological progress and the fact that they are higher and higher have nevertheless considerably reduced the noise of wind turbines. While some admire and find them pretty, many people complain that wind turbines change the landscape.

Before each installation, studies are now mandatory, and landscapers are associated with each project. It is noted that wind turbines can hinder the passage of migratory birds that are diverted in their aerial journey. Before installing them, these passageways must be taken into account.

  • The installation of wind turbines in the marine environment displaces the balance of life of the fauna and flora, and some fishermen complain that they prevent trawling (net that is dragged on the bottom of the sea).
  • A wind turbine does not operate 24/24 hours, and when it does not work, it must be replaced by more polluting traditional energies.
  • Wind turbines are quite difficult to transport because of the size of the blades and masts and require exceptional road convoys that are sources of pollution.

A more complex reality

If the promises of domestic wind energy are compelling, the reality may be a little less favorable. Indeed, the costs of the installation are, compared to the production, quite high. While self-consumption (i.e. the direct consumption of energy produced to meet the needs of the home) is possible, professionals most often recommend designing a system coupled with solar power.

  •  Some scams have unfortunately tainted the reputation of domestic wind (such as photovoltaics), and caution is required when starting such projects. Very low acquisition and installation prices and promises of too high performances should encourage caution.

If the electricity produced by a wind turbine can be stored, its power output, expressed in kilowatt-hours (kWh) is significantly lower than that of solar. The noise generated by moving blades is also often pointed out by users.