A wind farm is always assessed against the worst case: the wind condition producing the highest noise level at the most exposed receptor, in order to obtain its Environmental Qualification Resolution (RCA), in line with the SEA’s specific guidance. That is the right way to show a project is viable. But a wind farm does not operate in its worst case: it operates across a full year, with wind speeds and directions that change hour by hour. Assessing only the worst case can lead to restricting the whole farm all year because of a condition that occurs for a few hours.
This service characterises the farm’s noise by real operating condition and, from there, defines operational strategies that meet the standard without giving up generation that was compatible with it all along. We deliver operational strategies for different wind directions and speeds, for each wind turbine, specifying the sound power level and the operating mode required, together with an estimate of the energy generated under each strategy.
Who it is for
Wind farm owners and developers, at three distinct moments: at feasibility, while the investment decision still allows design changes; before construction, when it pays to anticipate which conditions will prove critical; and in operation, once the farm is generating and the commitments have to be met.
Applicable regulation
D.S. No. 38/2011 of the Ministry of the Environment, the noise emission standard for stationary sources, and D.S. No. 14/2024 of the same ministry, which replaces it gradually.
Scope and methodology
Continuous noise measurements at receptors, covering the range of wind conditions that actually occur at the site; acoustic modelling of the farm for different operating conditions, by wind speed and direction; compliance assessed condition by condition, rather than as a single worst-case evaluation; and the definition of operational strategies, that is, which wind turbines, under which wind conditions and at which times of day, should run in a reduced mode in order to comply.
Deliverables
A report with the compliance assessment by operating condition, and the proposed operational strategy, stating the conditions under which each operating mode applies for each wind turbine.
How we help
The outcome is not just a compliance report: it is an operating criterion that allows the greatest possible amount of energy to be generated for the real conditions of the wind farm, while verifying compliance at the receptors of interest. If your farm already holds an RCA and you want to review its operation, tell us its location and turbine model and we will let you know what information we need to start.
Frequently asked questions
How is this different from wind farm noise studies for the SEIA?
Studies for the SEIA assess the project before it obtains its RCA, against the worst case, to demonstrate compliance for the scenario the SEA requires in its specific guidance. This service starts from there: it takes the farm already assessed — or with the design well advanced — and looks for the best possible operation within the standard, wind condition by wind condition. One answers whether it can be built; the other, how to operate it in compliance.
Does it work if my farm is already built and operating?
Yes. It is one of the three moments when this service applies, along with the feasibility stage and the period before construction. With the farm running, the real conditions of the site can be measured rather than estimated, which is precisely what allows the operational strategy to be refined. In fact, if you are already in operation, that is the most accurate setting for the optimisation, because you can provide real data from all of your wind turbines.
Does optimising mean generating less?
That is not the aim. Assessing against the worst case can lead to restricting the whole farm all year because of a wind condition that occurs for a few hours. Defining operational strategies for different real operating conditions makes it possible to apply restrictions only when and where they are needed, and to operate without limitations the rest of the time. In our experience we have seen substantial improvements in energy generation through optimisation, meeting the standard across different conditions while also generating the greatest possible amount of energy.
How long does the continuous measurement campaign last?
Although the SEA’s wind farm noise guidance and D.S. No. 14/2024 refer to a minimum of 14 days, we recommend allowing at least one month per measurement point. In some cases 14 days may not yield enough data on the farm’s noise emission to reach a correlation coefficient between measured noise level and wind speed of r²≥0.6.
What information do you need to start?
We need to know whether you have continuous L90 fast measurements every 10 minutes and audio recordings covering at least 14 days, together with wind speed and direction data, energy generation and the actual operating modes of your wind turbines during the noise measurement campaign, as well as the turbine data sheets, their location and that of the receptors of interest.
What software do you use for the modelling?
We work with CadnaA for noise modelling across the different wind directions and speeds.
Technical background
This service builds on our own research presented at international congresses: noise measurement criteria for wind farms under D.S. No. 14/2024, presented at the XIV Ibero-American Congress on Acoustics (FIA2026). Our list of publications also includes Variables involucradas en la optimización de un parque eólico para lograr cumplimiento normativo (2024), Recomendaciones para obtener niveles de inmisión producto del monitoreo continuo de ruido (2024) and Challenges of environmental assessment of wind farm noise in Chile: Background noise (2022).
Related service
If your farm has not yet entered the SEIA, the service you need is wind farm noise and shadow flicker studies for the SEIA. This page begins where that one ends: one assesses before the RCA, the other optimises operation.
Related projects
Recursos gratuitos para tu proyecto
Guía de preparación al D.S. N°14/2024 y checklist acústico para ingresar al SEIA, en PDF. Te los enviamos por correo.