Every wind farm entering the SEIA faces the same question: how to demonstrate that it will not cause unacceptable noise or shadow flicker at nearby dwellings and/or on native fauna. These are two distinct effects with two distinct methodologies, and both now have explicit rules in Chile. The most relevant development: the new stationary-source noise standard devotes a full article to wind farms, with a measurement procedure that applies to no other stationary source.
Article 17 of D.S. No. 14/2024: a rule of its own for wind farms
The Ministry of the Environment’s D.S. No. 14/2024, published on 27 February 2026 to replace D.S. No. 38/2011, comes into force 18 months after publication for projects entering the SEIA and 30 months after publication as a general rule. Its Article 17 sets a method specific to wind farms: for external measurements, the emission level is obtained from 10-minute measurements of the L90 percentile level in dBA, which are correlated with the wind speed recorded at hub height. That correlation must yield a regression curve with an R² coefficient of 0.6 or higher. And the exterior emission level of a wind farm is not corrected under Article 20 — residual noise, impulsive noise, and open or closed doors and windows — unlike every other stationary source.
Because most wind farms are sited in rural areas, the applicable limit is not a fixed number: Article 11 refers to Tables No. 6 and No. 7, whose values depend on the rural background noise level measured at the receptor itself (Article 12). The quieter the surroundings, the stricter the limit. Characterising background noise properly defines the standard against which the wind farm will be assessed throughout its operating life. That said, the new standard sets stepped limits, and for the night-time period (the most critical case) the limit starts at 40 dBA.
The baseline drives everything: background noise correlated with wind
The SEA guidance on applying the noise standard to wind farms requires background noise to be measured in at least three hub-height wind speed ranges (6-8, 8-10 and 10-12 m/s) and recommends continuous monitoring of at least 14 days, because measurement variability at a single wind speed can be very high. However, to date neither D.S. No. 14/2024 nor the technical proposal for the measurement and prediction protocols of the new stationary-source noise standard (D.S. No. 14/2024 MMA) indicates that rural background noise measurements must be carried out by wind-speed ranges — a fundamental point that should be resolved by 27 August this year, the deadline for the SMA to publish the definitive measurement protocol.
Shadow flicker: thresholds and deliverables
Shadow flicker occurs when the blades interrupt sunlight and cast a pulsing shadow over a dwelling. The SEA assessment criterion requires two scenarios to be modelled: the worst-case astronomical scenario — clear skies and continuous operation — with a threshold of 30 hours per year and 30 minutes per day, and the real scenario, which incorporates the site’s usual meteorological conditions, with a maximum of 8 hours per year (a threshold that comes from the German standard, which is the one the SEA recommends applying). Modelling is carried out in specialised software — WindPRO, WindFarmer, WindFarm or OpenWind — and is submitted with the daily shading duration per receptor to a precision of one minute, shading isolines, georeferenced mapping and a kmz file.
How we help
At Acústica Austral we carry out wind farm noise and shadow flicker studies, from feasibility through to verification in operation: baseline campaigns with class 1 instrumentation, correlation with hub-height wind data, acoustic and shadow modelling, and technical responses to SEA observations. We produced the acoustic characterisation of wind farms in Chile and the wind farm noise measurement protocol for the Ministry of the Environment, and we have delivered the noise and vibration studies for large-scale wind projects in the SEIA (renewable energy).
If you are developing a wind farm or have already received observations, book a 20-minute call and we will review your case.
He leads Acústica Austral’s environmental noise and vibration studies for the SEIA across energy, port and infrastructure projects, and has contributed to reference work for Chile’s Ministry of the Environment.
Meet the team →Free resources for your project
Guide to the D.S. N°14/2024 and the acoustic checklist for entering the SEIA, in PDF. We email them to you.