Training in environmental assessment on avifauna in wind farms

In our 24 years of specialization in the energy sector, we have always encouraged the training of our technicians, so today we are talking about the course on Evaluation and monitoring of the impact of PPEE on fauna taught by the Higher Institute of the Environment (ISM) through our former colleague Jon Domínguez del Valle.

The new promotion of renewable energy makes it necessary to implement improvements in the environmental impact assessment and monitoring system, in order to ensure the protection of the environment according to the criteria established in the Law 21/2013 of December 9.

Through this course, theoretical and practical tools have been introduced to obtain reliable and comparable information, and to carry out rigorous evaluations and monitoring of flying vertebrates and their habitats, in order to minimize their effects and facilitate their integration into ecosystems. Among them, the following stand out:

Analysis and selection of locations

Through this process, the impact on fauna is evaluated in large potential areas for the installation of wind farms.

This prior evaluation makes it possible to identify the most obvious impacts in future locations, avoiding the most conflictive areas and planning the necessary mitigation measures.

During this phase, thematic public cartography processed using geographical information systems (GIS) will be used, where the presence of figures for the protection of fauna and vegetation will be taken into account, highlighting Protected Natural Areas and areas of Natura 2000 Network; presence of threatened flora or protected habitats, land uses, etc.

After delimiting large areas suitable for the development of wind projects, the next step is the analysis and selection of specific locations in those areas. During this stage, consultations will be carried out with experts, administrations, detailed bibliographic searches and visits to the possible location, as this is a key stage in the development of projects.

Base studies

After identifying the specific locations for the development of the Wind Farm, a detailed and on-the-spot characterization of the faunal elements present in the study area will be carried out.

During these basic studies, the necessary information must be provided to empirically quantify the distribution, relative abundance, behavior and habitat use of the species.

These studies aim to:

• Close the information gaps detected in the previous phases.
• Predict the impact on birds and bats and their habitats
• Get information so that the project design minimizes impact.
• Collect information to evaluate the effectiveness of impact predictions and compare with post-installation data.
• Get useful information for identifying and developing mitigation measures.

Monitoring mortality in wind farms

One of the main impacts caused by the presence of wind farms is the possible mortality during their operation, so their control is usually the main monitoring factor.

Therefore, existing techniques are provided for the control of the search for bird and bat carcasses in the immediate environment of wind turbines, which will make it possible to evaluate the impact by establishing the real number of injured individuals, relating mortality to the characteristics of the wind farm, confirming the impact estimates of pre-operational models, establishing a list of affected species and evaluating mitigation measures.

Mitigating the impact of wind farms

The consequences of the impacts of wind farms on wildlife make it necessary to implement effective mitigation measures.

This is an adaptive process that must be implemented throughout the life cycle of the project (planning phase and operational or operational phase), at the same time that it must be repeatable and comparable in order to evaluate the effectiveness of the measures.

All the negative consequences of this type of project are not predictable or avoidable during planning, so it is necessary to define protocols to mitigate or avoid them.

Among the specific measures studied, with the potential to reduce the impact on birds and bats, stand out: The shutdown of wind turbines in real time, planned shutdown of wind turbines, habitat management, visibility of wind turbines, systems on surfaces to induce changes in the behavior of individuals and drive them away, deterrence methods with sound and visual stimuli and compensation measures.

Base study designs

The theoretical principles for designing wildlife impact studies on wind farms are common to those applied in the evaluation of other types of projects. However, it is essential to consider some of the peculiarities related to wind energy, such as: you work in large areas where target species may be scarce and you have particular control parameters, such as mortality due to collision.

In wind farms, studies are usually observational and include prior evaluation of the environment, risk analysis and monitoring during the construction and operation phases. The impact is defined based on the prior evaluation of the environment, in which the number of individuals is quantified, how they are distributed in space and it is determined what types of habitats they occupy. The combination of abundance data with vegetation parameters, food availability, disturbances, climate, etc., provides indicators on population oscillation, their causes and the effectiveness of conservation measures.

References: Both photographs taken by Alfonso Guío

Mirian Peñarrubia, Environmental Assessment

Rosa María Colás, Environmental Assessment