Acoustic Study for Wind Farms and BESS

What the acoustic study is

The noise or acoustic study assesses the sound impact a project or installation generates on its surroundings, determining whether the expected noise levels meet the acoustic quality objectives and the immission limit values set in the applicable regulation. At Ideas Medioambientales it is particularly focused on wind farms and battery energy storage systems (BESS), two project types where we concentrate most of our activity and accumulated experience, with projects delivered across the whole of Spain.

Applicable regulatory framework

The national reference framework is Spanish Law 37/2003 (the Noise Act) and its implementing regulation (Royal Decree 1367/2007), which set the acoustic quality objectives by land use (residential, industrial, healthcare, educational) and the sound immission limit values in the outdoor and indoor environment. Spanish autonomous regions and municipalities may set their own, more demanding, noise regulation, so we always verify the applicable municipal ordinance in addition to the national framework, regardless of the region where the project is located.

For wind farms and BESS projects the CNOSSOS-EU calculation method is applied, the European Union reference methodology for environmental noise modelling, which we have applied in dozens of studies across the whole of Spain.

Acoustic study for wind farms

The noise generated by turbines during operation is one of the most scrutinised impacts in the environmental processing of wind farms. The study must consider:

• The sound power of each turbine model, obtained from the manufacturer's certified datasheet, distinguishing operating modes (standard and reduced-noise mode).
• The cumulative effect where other nearby wind farms are in processing or already operating.
• Specific modelling at each dwelling or population centre in the surroundings, with particular attention to the night-time period, which is usually the most restrictive.
• The possible need to set reduced operating modes (curtailment) on specific turbines if exceedances are detected at some receptors.

Acoustic study for BESS installations

Battery energy storage systems (BESS) generate continuous noise, mainly from the container HVAC and cooling systems, as well as the associated transformers and inverters. The BESS acoustic study analyses:

• The combined sound emission of all the installation's BESS containers, considering their layout and combined effect on receptors.
• The continuous nature of the noise (24 hours), unlike other intermittent sources, which makes the night-time analysis particularly relevant.
• Adaptation to specific regional regulatory frameworks that are updating their criteria in line with the growth of this type of installation.
• Common corrective measures where exceedances are detected: perimeter acoustic barriers, relocation of containers relative to sensitive receptors, or selection of equipment with lower certified sound emission.

Methodology

1. Characterisation of the sound sources: sound power of turbines or BESS containers, obtained from the manufacturer's datasheets.
2. Identification of sensitive receptors: dwellings, population centres and other protected uses around the project.
3. Sound propagation modelling using CadnaA software in line with the CNOSSOS-EU methodology, considering topography, meteorology and terrain obstacles.
4. Calculation of immission levels at each receptor, distinguishing the day, evening and night periods.
5. Comparison with the applicable acoustic quality objectives according to the municipal and regional zoning.
6. Proposal of specific corrective measures if limits are exceeded at any receptor.

Common mistakes

• Using generic catalogue sound powers instead of certified data for the specific turbine or BESS container model to be installed.
• Failing to consider the cumulative effect with other nearby wind farms or BESS installations in processing.
• Omitting the specific municipal acoustic zoning of each municipality, regardless of the region where the project is located.
• Not correctly distinguishing the night-time period, critical both for the continuous BESS noise and for night-time turbine operation.

Why choose Ideas Medioambientales

We are specialists in acoustic studies for wind farms and BESS projects, with CadnaA and CNOSSOS-EU methodology applied on dozens of projects across the whole of Spain. We know in depth the regional and municipal regulation of each territory where we work and have resolved numerous acoustic corrections arising from template contamination or criteria that shift between projects. Our in-house multidisciplinary team, with more than 25 years of experience and ISO 9001, 14001 and 45001 certification, works across the whole of Spain from our offices in Albacete and Madrid.

Tell us the characteristics of your wind farm or BESS installation and its location and we will tell you which acoustic regulation applies and how quickly we can deliver the study.