Definition:
Today, wind energy is used mainly to produce electricity through wind turbines connected to large electricity distribution networks, among others. Wind farms built on land represent an increasingly cheap and competitive source of energy, and even cheaper in many regions than other conventional sources of energy.
How is wind energy produced and generated?
Wind energy is related to the movement of air masses that move from areas of high atmospheric pressure to adjacent areas of low pressure, with speeds proportional to the pressure gradient.
Winds are generated due to uneven heating of the Earth’s surface due to solar radiation; between 1 and 2% of the energy from the Sun is converted into wind. During the day, continents transfer more solar energy to the air than to bodies of water, causing it to heat up and expand, so that it becomes less dense and swells. Cooler, heavier air from the seas, oceans, and great lakes kicks in to take the place left by warm air.
To take advantage of wind energy, it is important to know the variations of the diurnal, night and seasonal winds, the variation of the wind speed with the height above the ground, the entity of the explosions in short periods of time, and the maximum values that occurred in historical data series with a minimum duration of 20 years. To use wind energy, it is necessary for it to reach a minimum speed that depends on the wind turbine to be used, but it usually starts between 3 m / s (10 km / h) and 4 m / s (14.4 km / h ), speed called “connection speed” and not more than 25 m / s (90 km / h), speed called stop speed.
Wind energy is exploited using wind machines or windmills can transform wind energy into usable rotary mechanical energy, either to directly power operators or to power power generating machines. In the latter case, the most widely used today, the conversion system comprising an electric generator with its control systems and connection to the grid is known as a wind turbine. In these, the wind energy moves a propeller and, by means of a mechanical system, the rotor of a generator is rotated, usually an alternator, which produces electrical energy. For their installation to be profitable, they are usually grouped in concentrations called wind farms.
A wind turbine or wind turbine is a machine that transforms wind energy into mechanical energy through oblique blades connected to a common shaft. The rotary shaft can be connected to various types of machines, whether for grinding grains (mills), pumping water or generating electricity. When it is used to produce electricity, it is called a wind turbine. Wind machines are of remote origin, and the oldest ones function as windmills.
Advantages of wind energy
It is an inexhaustible source of energy:
This makes it a renewable energy source. Wind is an abundant and inexhaustible source, which means that you can always count on the original source that produces energy. It has no expiration date. In addition, it is available in many places around the world.
It takes up little space:
To produce and store the same amount of electricity, a wind farm requires less land than a photovoltaic energy field. It is also reversible, which means that the surface occupied by the wind farm can be easily restored to renew the pre-existing territory.
It does not pollute:
Wind energy is a cleaner energy source after solar energy. This is because, during the generation process, it does not involve a combustion process. Therefore, it does not produce toxic gases or solid waste. To have an idea. A wind turbine achieves an energy capacity similar to that of 1,000 kg of oil. Furthermore, the turbines themselves have a very long life cycle before being removed for disposal.
Low cost:
Maintenance costs for wind turbines and turbines are relatively low. The cost per kW produced is very low in very windy areas. In some cases, the cost of production is the same as coal and even nuclear power.
It is compatible with other activities:
Agricultural activity harmoniously coexists with the activity of a wind farm. This means that it does not have a negative impact on the local economy, it allows the facilities not to interrupt the development of their traditional activity while generating a new source of wealth.
Disadvantages of wind energy
Wind is not guaranteed:
The wind is relatively unpredictable, so production forecasts are not always met, especially in small temporary units. To minimize risks, investments in this type of facility are always long-term, so the calculation of their profitability is safer. This drawback is better understood with just one piece of information: wind turbines only work correctly with gusts of wind between 10 and 40 km / h. At lower speeds, the energy is not profitable and, at higher speeds, it represents a physical risk to the structure.
Non-storable energy:
It is energy that cannot be stored, but must be consumed immediately when it occurs. This means that it cannot offer a complete alternative to using other types of energy.
Impact on the landscape:
Large wind farms have a strong impact on the landscape and are visible over long distances. The average height of the towers / turbines ranges from 50 to 80 meters, with rotating blades rising another 40 meters. The aesthetic impact on the landscape sometimes creates discomfort for the local population.
They affect birds:
Wind farms can have a negative impact on bird life, especially among nocturnal hijackers. The impact on the birds is due to the fact that the rotating blades can move at a speed of up to 70 km / h. Birds are not able to visually recognize leaves at this speed, fatally colliding with them.
