What is an Environmental Impact Assessment (EIA)?

Gail Rajgor

Planning permission and consents can be the death of many a renewable energy project. Which is why it remains vital to properly assess the environmental impacts of development.

A key area that developers must focus a great deal of attention on in the development phase of a project - and which must be accounted for in any planning application – is the prospective environmental impact of a project.

This is true for both onshore and offshore wind projects for example. In these cases, “professional advice should be sought from a consultant to ensure a comprehensive EIA is undertaken that can stand up to scrutiny,” advises the British association RenewableUK.

Visual impact, noise and the potential effects on local ecology and wildlife are invariably the grounds on which most objections to wind farms are based - and often upheld by planning authorities. These potential impacts need to be studied diligently by developers, with a detailed EIA report submitted as part of the final planning application.

According to the Global Wind Energy Council (GWEC), public objections to turbines on the perceived grounds they are eye-soars have been prolific over the years, and planning rules have developed to take account of this.

“Most countries with a wind power industry have established rules which exclude certain areas from development, such as national parks or nature reserves. Others have identified priority areas where wind power is specifically encouraged,” notes GWEC.

Meantime, recognising that visual impact can be a concern for neighbouring communities, developers are advised to plan locate turbines sensitively and reduce the impact,. This includes the use of computer modelling programs to show residents exactly how the turbines will appear from numerous different viewpoints.

Noise is another impact that developers have to focus on. While wind turbines are generally much quieter than traditional types of industrial energy generation plants, they are not silent:

“The sounds emitted from wind turbines can either be mechanical, from internal equipment such as the gearbox or yaw drive, or aerodynamic, from air moving past the rotor blades,” explains GWEC. “Modern turbine designs have effectively reduced mechanical sound through sound proofing so that the ‘whooshing’ aerodynamic sound is what can normally be heard.”

While this is less of a problem in highly remote rural locations, it can cause concern in other potential development areas and so planning legislation sets firm rules on noise that developers need to make sure they adhere to. “Permitted sound levels, including the distance between turbines and the nearest house, are generally determined at a local level. All wind farms must comply with operating rules laid down by the appropriate authorities, normally based on national recommendations,” GWEC adds.

Impacts on wildlife and local ecology must also be examined. “Problems are most likely to occur when the site is either on a migration route, with large flocks of birds passing through the area, or is particularly attractive as a feeding or breeding ground,” according to GWEC. “This can be avoided by careful siting.”

Offshore wind developers also have to ensure turbines and transmission infrastructure do not interfere with marine life and ecosystems. “National regulations ensure that project developers assess in both qualitative and quantitative terms the expected environmental impacts on the marine environment. These procedures ensure that projects comply with international and EU law, as well as conventions and regulations covering habitat and wildlife conservation.”

The information gathered for a project EIA is usually published in a report or environmental statement, which is then used within the consents process. As well as submitting the report to planning authorities, the developer must usually make the document available for public scrutiny (for example by placing it on a company or project website or in public libraries).

The most successful developers will ensure they “design-in” the results of their EIAs into development plans. “We choose our sites carefully to avoid potential effects on important wildlife and landscape areas, and we carry out Environmental Assessments which include ecological, archaeological, hydrological and socioeconomic assessments,” explains one of the leading global wind power developers - RES. “The Environmental Statements are an integral part of the layout design process, ensuring that our awareness of the environmental issues surrounding our development shapes the form the project takes.”

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