
Verlo siempre en Español
Verlo siempre en Español
According to the Spanish Wind Energy Association (AEE), at a distance of 400 metres from an operating wind turbine, the noise level is 37 decibels (dBA), similar to the hum of a microwave or refrigerator.
To put this into perspective, 65 dBA (the legal daytime limit in residential areas) contains approximately 19.5 times more sound energy than 37 dBA. This is because decibels are measured on a logarithmic scale, where a 10 dB difference represents a tenfold increase in sound intensity.
This level is below the usual limits for outdoor residential areas. The noise perceived by the human ear is measured in dBA, which is why they are used to assess its true impact.
The sound of wind turbine blades is so low that it blends into ambient noise. In fact, it is possible to have a conversation right under a turbine without raising your voice. But what level of noise qualifies as noise pollution?
In Spain, Law 37/2003 on Noise, and its implementation through Royal Decree 1367/2007, establish the permissible limits depending on land use. In residential areas, the maximum permissible outdoor noise levels are:
If wind turbines produce 37 decibels at a distance of 400 metres, it is clear that we are far from being able to speak of noise pollution.
So, what type of noise do wind turbines produce?
We can distinguish between two types of noise: aerodynamic and mechanical. The first type is the most common. It is generated by the movement of the blades as they cut through the air. Its intensity depends on the wind speed and the design of the blades. It tends to be more noticeable when the wind is moderate.
Mechanical noise is produced by the turbine’s internal components, such as the gearbox and the generator.
And does this noise harm wildlife? To build a wind farm, a positive Environmental Impact Statement (EIS) must be obtained. Wind farms cannot be built in protected areas or in places where the EIS is negative.
Moreover, wind turbines are not an obstacle to livestock farming. The land can still be used for grazing or herding animals.
Older turbine models are noisier than current ones, which have aerodynamic improvements and better sound insulation.
First, design and technology: the latest wind turbine models feature aerodynamically shaped blades and smart control systems that reduce noise during operation.
In addition, wind speed plays a role. The higher the speed, the faster the blades spin, which can increase the perceived noise level.
A wind turbine's maintenance condition and age are also key factors. Over time, wear and tear on components can lead to an increase in mechanical noise.
Finally, the type of location and terrain, such as the presence of hills, trees, or other natural barriers, can alter how sound spreads and is perceived in the environment.
Taking all these factors into account explains how the authorities regulate wind turbine installations to minimise their impact as much as possible.
In Spain, the regulatory framework is based on the 2011-2020 Renewable Energy Plan, in line with Directive 2009/28/EC of the European Parliament, which promotes the energy transition based on sustainability criteria.
This plan proposes a minimum distance of 500 metres between wind farms and residential areas and takes into account both acoustic and visual impact.
Regarding noise, the legal framework is based on Law 37/2003 on Noise, which aims to prevent, avoid, and reduce noise pollution. This law is implemented through two royal decrees:
In addition to the national framework, each autonomous community may apply specific criteria.
According to the document Environmental zoning for the deployment of renewable energies: wind and photovoltaic energy, from the Ministry for Ecological Transition and the Demographic Challenge, the following distances have been established in the different regions:
The national legal framework provides common ground, but the autonomous communities fine-tune or strengthen these measures based on each region’s specific characteristics.
Wind turbines do make some noise, but not noise pollution. They are below the legal limits, and thanks to technological advances, wind energy is increasingly quieter and more compatible with rural and natural environments.
In 2024, wind energy was once again the main source of electricity generation in Spain, for the second year in a row and the fourth time in history.
It accounted for 23.2% of the energy mix according to Red Eléctrica. That same year, 16.4 GW of new wind capacity was installed across Europe alone, according to Wind Europe.
Today, this renewable energy source could cover the electricity consumption of 84% of Spanish households, according to the Spanish Wind Energy Association (AEE).
Far from being a source of noise pollution, wind turbines are increasingly well integrated into their surroundings thanks to technological advances and strict regulation. Yet another sign that the energy transition is progressing in a sustainable and environmentally friendly manner.