Air quality assessment for wind turbines and wind farms
Air quality assessment for wind turbines evaluates airborne emissions from construction and operation and creates permittability and acceptance.
Wind energy stands for emission-free electricity generation. Even so, airborne emissions can arise around the construction and operation of a wind turbine, for example from construction site operations, earthworks or accompanying infrastructure measures. The assessment classifies these emissions by source and period and shows whether and where they may become relevant. Sources include diffuse dust from earthworks and vehicle movements as well as exhaust gases from mobile machinery, above all nitrogen oxides and particulates. Authorities and technical experts thus receive a verifiable basis, and residents more transparency. This is relevant above all in the construction phase, when earthworks, transport and machinery use coincide.
Air is a protected asset in its own right in the environmental impact assessment. The environmental impact statement (UVE) must describe the expected residues and emissions into the air as well as the increase in ambient pollution caused by the project, and it must name measures to avoid or reduce significant adverse effects. In addition, the EIA Act requires emissions of air pollutants to be limited in line with the state of the art and ambient pollution to be kept as low as possible. The results feed into the non-technical summary of the UVE, and the methods of impact assessment are described. These values serve as a technical framework for assessing the additional load from construction and operation.
In Austria, the benchmark for the assessment is the ambient air quality limit values of the Ambient Air Quality Act (IG-L). They apply for particulate matter PM10 as a daily mean of 50 µg/m³ with a limited number of permitted exceedances and as an annual mean of 40 µg/m³, for PM2.5 as an annual mean of 25 µg/m³, and for dust deposition at 210 mg/(m²·d) as an annual mean. Ambient pollution is calculated with a dispersion model that takes meteorology and terrain into account and is overlaid with the existing background load at the site. If a project lies in an area that is already burdened for a given pollutant, the irrelevance threshold takes on particular importance: additional contributions of up to 3 per cent of the limit value for short-term values and up to 1 per cent for long-term values are considered irrelevant there. The air quality assessment is aimed equally at developers, authorities and technical experts, and the assumptions of the dispersion model are disclosed.
In the course of preparing the UVE, we use the air quality assessment to create the basis for transparency, permittability and acceptance, especially in sensitive regions. We carry out a robust emission and ambient air quality analysis in line with the standards. For the dispersion of air pollutants and dust, we use a technically recognised dispersion model suited to the application, supplemented by CFD calculations where necessary. You receive practical recommendations for optimisation and concrete proposals for evidence preservation and monitoring. Which turbine type and construction method underlie the assessment is shown by the technical plant reports. The assessment complements the other UVE technical contributions for wind farms and the technical support for the permit procedure. For projects in Germany, we prepare the air quality assessment under the TA Luft and BImSchG.
