Planning process

Fishing

The construction, development and use of offshore wind farms can have adverse effects on fish and shellfish resources – on spawning, overwintering, nursery and feeding grounds, and migratory pathways.

The Centre for Environment, Fisheries and Aquaculture Science (CEFAS), a principal source of advice to the Government on marine environmental issues, believes that wind farming will not affect fish stocks as a whole. However, individual developments may have an impact on fish and shellfish at particular locations.

The scale of any impact is assessed as part of the Environmental Impact Assessment (EIA) (links to Communities and Local Government website), undertaken in consultation with the fishing industry and the Sea Fisheries Inspectorate, which is part of the Department for Environment, Food and Rural Affairs (Defra).

The Fishing Liaison with Offshore Wind and Wet Renewables Group (FLOWW)encourages open dialogue between the fishing industry and the wind energy sector, helping to foster closer relations between them.

Ornithology

There is currently debate about the effect of wind turbines on bird populations, bird habitats, breeding and feeding grounds, migration routes and other well-used flight paths. However, many of the perceived adverse effects can be eliminated through good design and location.

A significant proportion of the UK is protected for its ecological value, either for the presence of protected species, or for the habitat it provides. Any development proposed for these areas must be able to demonstrate either that there will be no damaging effects resulting from the construction and operation of the development, or that the development is of overriding national need.

However, birds do not always live in protected areas, and every proposed site must be assessed for the presence of birds, whether they use it for roosting, breeding or feeding, or even flying nearby. This is usually required as part of the Environmental Impact Assessment (EIA) (links to Communities and Local Government website) and forms a key part of the planning application.

Good planning can help reduce any adverse effects. Examples include a habitat management plan (before work starts), and the presence of an ecological officer during construction (and decommissioning). It is also important to time work carefully, taking into account migration habits.

Noise

Noise is defined as any sound which is especially loud, harsh or undesirable. It can be measured, and regulations exist to limit unacceptable noise – although any definition of unwanted noise will always be partly subjective. A further complicating factor is that some people are more sensitive to noise than others.

Noise from wind turbines is the sound produced by the turning blades and the gearbox, generator and hydraulic systems within the nacelle. In modern turbines, however, this mechanical noise has been reduced so that it is almost non-existent.

Perceived noise from wind turbines is the sum of the ambient or background noise and the noise from the turbines. If turbines are in an industrial or urban area, for example, the ambient noise can mask turbine noise completely. Trees can also mask distant wind turbine noise.

The latest turbines with capacities higher than 1 megawatt generally have source noise levels of between 100 and 106dBA. So they have to be placed between 200 and 300 metres from the receptor to reach a sound pressure level of between 45 and 50dBA.

Developers are obliged to carry out noise predictions, and evaluate the likely effects of noise from wind turbines on local residents and those working in the vicinity. They compare the predicted noise levels of turbines with the existing background level. The assessment should be able to demonstrate compliance with national noise regulations. Developers generally present their noise predictions as contour maps, with contours joining locations of equal noise level.

It is important to note that limits apply to noise levels outside dwellings, as the assessment report is aimed at protecting areas used for relaxation, and where a quiet environment is highly desirable. Noise levels inside a property will be approximately 10dBA less than those outside, even when a window is open.

You can find out more in the Sustainable Development Commission (SDC): wind power in the UK report, published in May 2005.

The landscape and other visual effects

The effects on the landscape and other visual implications of wind farm developments are among the most far-reaching. They are generally of greatest concern to the public, and often the reason why people oppose wind farm proposals. However, changes to the landscape happen all the time, and wind farm developments can often become part of it quite readily.

Wind energy developers generally avoid the most sensitive landscapes, such as National Parks and Areas of Outstanding Natural Beauty. They also carry out assessments of the landscape and visual impact when preparing planning applications.

An Environmental Impact Assessment (EIA) (links to Communities and Local Government website) takes place alongside the landscape and visual impact assessment and the design of a wind farm. It is a continual process. Considering the landscape implications of a proposal during the design process can produce schemes that are more acceptable, and can reduce or even remove any potential adverse effects.

Any potential developer of an offshore wind farm must also undertake a seascape and visual impact assessment (SVIA) as part of the Environmental Impact Assessment (EIA) process.

The Sustainable Development Commission (SDC): wind power in the UK report was published in May 2005, and includes findings on landscape issues.