This renewable power source is spreading, but what wind energy is? In summary, wind energy is the technique that turns wind, this inexhaustible resource, into electricity. This is done by means of wind turbines – built on land or at sea – that use the movement of blades as the main basis for their operation.
Not surprisingly, this energy solution is among the most sustainable, safe, and fundamental in reducing the use of non-renewable resources and pollutants to the environment – capturing the wind does not emit greenhouse gases that, in turn, contribute to global warming.
For all this to be possible, some structural and climatic conditions need to exist in harmony: the construction of a wind farm – made up of at least five wind turbines -, the air mass to have a density greater than or equal to 500 watts per square meter (W/m²) at a height of 50 meters, and the wind speed to be seven to eight meters per second (m/s).
How does wind energy work?
The wind turbines – those giant wind turbines that cross our landscape – are responsible for capturing the wind’s energy and, thanks to physics rules, turn it into mechanical energy – which make each blade move.
Using this behavior in our benefit, we can make power of it, to sustain our homes, offices, hospitals, buildings and public lights.
This renewable source of energy is kind of instable, though. At the end of the day, it needs to be strategicly place so that we take advantage from it. To make the wind-to-energy magic happen, we need some important components, like:
- Rotor: this is the area that groups the three blades together, captures the force of the wind and takes that to the generator, turning it into mechanical energy;
- Multiplier box: it’s function is to increase the rotation force of the mentioned blades, reaching even 150 revolutions per minute;
- Generator: this is what converts the mechanical energy of the rotation into electrical energy.
After that, underground cables carry this energy to the substations in the region, and then to the distribution networks of the electricity companies.
The difference between onshore and offshore wind farms
Did you know that in addition to onshore wind farms, it is also possible to install turbines on the open sea, the so-called offshore wind farms?
The main distinction between onshore and offshore wind is where the bladed turbine will be installed – on land or at sea. Offshore wind energy has become a “next step” as the size of the turbines has increased, as has the potential for generation.
On land, the maximum generation capacity of the turbines reaches 5.6 megawatts (MW). At sea, there are projects pointing to a capacity of almost double, 12 MW, and some tests reach 15 MW.
Another advantage of offshore wind is that the winds at sea encounter fewer obstacles. There are no mountains, for example, that block the action of the winds, so, normally, the conditions are of greater intensity and constancy in the performance of the winds.
In the world today there are already offshore wind farms in Europe and Asia, generally up to an ocean limit of 80 meters deep. In them, the turbines are installed with pillars that go to the bottom of the sea.
On top of that, it is necessary to use floating structures, similar to those on oil platforms, but most are still in the testing phase.
Transmission, on the other hand, occurs via submarine cables, allowing integration with onshore energy transportation systems.
Wind energy advantages and pros
Among the major environmental and social 7 advantages of wind energy are:
- It has an inexhaustible source;
- It does not emit pollutant gases;
- It does not generate residues;
- It reduces the emission of greenhouse gases; – it’s a great allie to fight climate change and reduce carbon footprint.
- Wind energy guarantees the creation of jobs and income where the farms are installed;
- Generates investment in disadvantaged regions;
- Brings long-term financial benefits.
Wind energy disvantages and cons
Nobody is perfect, not even clean energy wind turbines. Here are some cons of this power source:
- Intermittency: this is wind energy problem. As the weather is not always the same, there’s not a very predictable amount of energy.
- Landscape modification: wind turbines cause considerable visual impact on the site where they are installed.
- Environmental impact: although this clean energy is a great way to reduce the carbon footprint, it can be a challenge for animal life: birds that may collide with the turbine blades.
- Noise impact: they are not very silent as solar panels. The turbine blades movement can be heard in 200 meters away, diminishing the quality of life for the surrounding residents.
Main advantages of wind energy
The use of a clean and inexhaustible resource is, without a doubt, a great ecological benefit – but it doesn’t stop there. This type of production, besides not emitting greenhouse gases, does not generate residues for the environment.
Another point is that there are no costs to access the raw material (after all, we are talking about wind) and the investment for the implementation and maintenance of wind farms is relatively low and generates new job opportunities.
The disadvantages of wind energy – and how they are solved
The dependence on wind means that this type of electricity generation is only possible in regions that have ideal climatic conditions – as seen above: air with a density greater than or equal to 500 watts per square meter (W/m²) at a height of 50 meters and a wind speed of seven to eight meters per second (m/s).
And, even in this case, it is necessary to carry out Environmental Impact Studies (EIA) and the Environmental Impact Report (RIMA) to ensure that there will be no damage to the animals, environment, and residents of the surrounding area.
A previous study is needed to guarantee that the facilities will not be on the route of birds and bats – they can be seriously injured if they pass through these regions. Another problem is the possible alteration of the migratory flow of these animals.
In the case of humans, the issue is mainly the noise and visual pollution they can cause if they are too close to houses.
Last but not least is the impact of wind turbines on meteorological radar. These devices, essential for predicting weather catastrophes, can have their results seriously altered if they are close to wind turbines.