Cumulative Impacts of Wind Turbines

The Cumulative Impacts of Wind Turbines is an extremely important consideration given the proposed proliferation of industrial wind turbines across Ireland.

The SEAI describes Cumulative Impacts as encompassing “the combined effects of multiple developments or activities on a range of receptors” or simply the combined effects of a set of developments, taken together. There will be impacts on landscape and visual amenity, species and habitats as well as social and economic effects.

Consider, for example, an industrial wind turbine installation of 15 turbines in a rural area that has been a feeding ground for hen harriers.  Planning may have been granted on the basis that the site is used infrequently and that there are sufficient other feeding areas.  However, subsequent development of other installations of turbines perhaps a few kilometres or more from the original site may reduce further the feeding areas but also interrupt the flying patterns of the species, forcing it to find new feeding areas.

The cumulative impact is greater than the sum of the impacts of individual developments. The cumulative impacts of wind turbine installations can be highly significant and are extremely complex to assess. It is for this reason that very little value has been placed on cumulative impact assessments to date. Planners are generally ill-equipped to carry out the detailed assessments required and may simply

operate on the principle that the imperatives of addressing the effects of climate change outweigh any potential impacts.

Of course the actual impacts of wind turbines on CO2 emissions are not assessed at all and the glorious claims of the wind developers remain unchallenged.

According to Scottish Natural Heritage, strategic cumulative impacts assessment should be undertaken as part of the preparation of:

  • Development Plan Policies and Supplementary Planning Guidance;
  • Strategic Environmental Assessment; and
  • Renewable energy capacity assessments

There is no evidence in the current Wind Energy Guidelines (2006) or in the proposed revised Guidelines that cumulative

impacts have been considered. Furthermore, the absence of a proper Strategic Environmental Assessment for ALL industrial wind installations and not just the “Export Project” component means that there are serious shortcomings in planning policy that will inevitably result in unacceptable and irreversible impacts on a great number of communities across Ireland.


SEAI.2012.GoodPracticeWind. View

Scottish Natural Heritage.2012.Assessing the cumulative impacts of onshore wind energy development. View



The Irish countryside is home to a rich array of wildlife and flora, including otters, pine martens, red squirrels and pygmy shrews among many others. Some, such as the otter and the red squirrel, are on the International Union for Conservation of Nature’s (IUCN) Red List and so it is of paramount importance that we ensure their continued survival.

Terrestrial Ecology

The Habitats Directive 92/43/EEC forms the cornerstone of Europe’s nature conservation policy and affords protection to all wildlife, plants and their habitats.

It is with reference to this directive that the impact of any large-scale developments on wildlife and habitats must be considered. Developers are obliged to conduct detailed surveys over extended periods of time and report the results as part of their planning submission.

There is already evidence that Developers may seek to give scant regard to ecological affects in their planning submissions. Coillte’s submission for a proposed wind farm in Cullenagh, Co. Laois in 2013 is a case in point and contained clearly inadequate surveys. For example, the Developer made no reference to the Red-Listedotter which is known to exist in the area and did not, as required under the Habitats Directive, apply for a derogation licence before it commenced surveying bats.

The adverse impacts of wind energy developments on habitats is influenced by a range of factors including the proposed widening of roads and bridges to facilitate access during construction, the actual construction process itself which involves the pouring of concrete foundations capable of supporting

turbines up to 185m tall, cabling for access to the grid and the ongoing maintenance of the turbines.   All of these will be hugely damaging to the environment and local wildlife and habitats.

Not only does the impact of each proposed wind farm need to be properly assessed, but the combined cumulative impact of so many turbines in one region also needs to be carefully assessed by planners. The construction and maintenance of approximately 2000 super sized turbines, and the associated infrastructure to support them can only have an enormous negative impact on our wildlife and their habitats.

It is of the utmost importance to preserve and protect the fragile eco-diversity of the countryside and the habitats that support it. These habitats are already under threat from other sources, such as conventional farming methods, so it is imperative that we consider the massive impact that these proposed developments would have on local ecology.


European Commission.1992. Habitats Directive 92/43/EEC.  View

European Commission. IUCN Red List. View

Wind turbines & their impact on birds

Individual wind turbines are already known to adversely impact on birds mainly in terms of displacement, risk of collision and loss of habitat. It therefore stands to reason that the cumulative effect of the construction and operation of a potential 2,000 (approx) large-scale turbines in the Midlands will be substantial on bird populations.


According to a study by Birdlife International (2013) on behalf of the Bern Convention, the main impacts of wind turbines on birds are as follows:

1. Displacement

Displacement and disturbance can occur during construction and operation of the turbines and is caused by the structures themselves, the associated infrastructure and human activity. This has potential impacts on breeding productivity and survival. The level of impact depends on the availability of unaffected habitat in the area.

 2. Collision Mortality

Large birds such as geese and swan species for example are particularly vulnerable to collision, especially where turbines are badly sited and/or the overall design of the wind farm is poor. This is particularly the case where wind turbines are in areas intersecting flight routes between feeding and breeding or roosting locations.

3. Habitat Loss and Fragmentation

During the construction of wind turbines, habitats can be seriously harmed and fragmented. Suitable feeding habitats and potential nesting sites can be substantially reduced as the building of access roads and other related infrastructure cause fragmentation and disturbance. The construction of roads, bridges, turbine foundations and related works such as drainage can alter sensitive habitats, changing the natural balance and the flora and fauna found there.

4. Range Reduction

This issue is closely related to the fragmentation of existing habitats. Many species defend their “ranges” during the breeding season. The construction of wind turbines on or close to a “home range” can alter a bird’s territory forcing it to compete for space/food with neighbouring birds.

According to Birdwatch Ireland, Ireland is home to 25 Red List and 90 Amber List bird species, meaning that they are of high and medium conservation concern respectively.  Planners must insist that developers follow best practice of a two year survey period as set out by Scottish Natural Heritage (2013) in order to ensure that the impact on these species at risk is properly evaluated as part of the planning process.


Birdlife International et al (2013). Wind Farms and Birds: An Updated Analysis of the Effects of Wind Farms on Birds, and Best Practice on Integrated Planning and Impact Assessment. View

Bern Convention – Council Decision 82/72/EEC (1981). View 

Birdwatch Ireland – Birds of Conservation Concern in Ireland. View 

Scottish Natural Heritage (2013).  Recommended bird survey methods to inform impact assessment of onshore wind farms. View

Aquatic Ecology

Aquatic ecology investigates the interplay between aquatic organisms and their physical, chemical, and biological environment. Wind farms can have devastating impacts on aquatic systems.


Ireland’s aquatic systems and wetlands support internationally significant populations of threatened species such as the Atlantic salmon (Salmo salar), white-clawed crayfish (Austropotamobius pallipes), freshwater pearl mussel (Margaritifera margaritifera), and marsh fritillary butterfly (Euphydras aurinia). Ireland is also particularly rich in bryophytes, lichens and algae and supports internationally important populations of non-marine molluscs and water beetles.

There are two types of Pearl Mussel in Ireland, one called Margaritifera margaritifera and the other is the very rare Margaritifera durrovensis, which is only known in the Nore Catchment. The Freshwater Pearl Mussel is listed under the EU Habitats Directive in Ireland (Annex II: protected within Special Areas of Conservation (SAC) and candidate sites). The Pearl Mussel is ranked in the highest conservation concern category by the Environmental Protection Agency (EPA).

The Pearl Mussel requires very high quality rivers with clean river beds and waters with very low levels of nutrients. The presence of sufficient salmonid fish to carry the larval glochidial (juvenile) stage of the Pearl Mussel life cycle is also essential.

In relation to Wind Energy development the following should be considered:

  • Detailed mitigation measures are required to ensure there is no effect on protected habitats or water courses.
  • Aquatic ecology surveying, the personnel used, the methods used, the timing and frequency, sampling methods etc.
  • The true fishery value of the development and the downstream affected areas would need to be assessed.
  • Amelioration measures where negative impacts are predicted e.g. organic pollution, sedimentation, acidification, siltation changes in water flows and forestry clearing.
  • The probable necessity for alternative locations for wind energy developments in view of the potentially devastating effects on aquatic ecology.


Habitats Directive (92/43/EEC) updated 2007 to include latest versions of annexes. View

Environmental Protection Agency. View