Impacts of Wind Energy Projects and their Assessment

"Screening" is the first step in any impact assessment process, and it focuses on assessing whether an impact assessment is necessary for a planned wind energy project. This is a preliminary exercise which assesses the type, size, characteristics and location of the proposed wind energy project, the sensitivity of the receiving environment (the World Heritage property’s OUV), attributes and other values) and the types of likely impacts.

The screening process should identify whether a wind energy project proposed or planned within a World Heritage property, its buffer zone or its wider setting has the potential to have an impact on the attributes of the property which convey its OUV. At this stage, the project description should be specific enough to allow to decide whether an impact assessment is needed or not.

What if available information is not enough?

In certain cases, the wind energy project being assessed may not be specific or detailed enough to make any judgments in this regard. This may be because a plan only focuses on the selection of one suitable area for the deployment of a wind energy project.

In such case, either more specific details should be worked out or the screening and impact assessment process might apply the ‘precautionary principle’ approach and look at multiple alternatives, including a worst-case scenario (for example, highest number of wind turbines, maximum heights of wind turbines, etc.).

See the definition for precautionary principle used by the European Parliament.

Screening criteria should be identified taking into consideration the national/regional/local legal framework, the nature of the proposed action or project and the specific characteristics of the World Heritage property.

1) Examples for the project related criteria are:

• Size and type of the project (for example, is this a project for the installation of a few new wind turbines or of a whole wind farm, the extension of an existing wind farm or a repowering project?)
• Size and typology of all elements of the wind energy project (for example, number of wind turbines, installation capacity, etc.)
• Layout of wind turbines (for example, type of wind turbines, their layout and the size, height)
• Proposed location of all elements of the wind energy project (including wind turbines but also sub-stations, ancillary facilities, access roads, etc.)

2) The characteristics and sensitivities of the World Heritage property that the planned project relates to will be directly linked to the property’s OUV and its attributes conveying its OUV.

The types of foreseeable, likely impacts will be derived from the combination of 1) and 2).

What other factors might need to be considered?

The screening process requires not only looking at the possible impacts of the proposed wind energy project, but it also requires a preliminary understanding of the possible cumulative impacts derived from this plan and other existing or soon-to-be developed projects.

As an example, a proposed project located outside the historic centre of a town might not have a direct impact on the historic area, but it could generate a cumulative impact on it when considering existing wind turbines in the buffer zone and the wider setting of the property together with other high-rise construction projects within and around the historic centre.

➔ See Note 6.

As a result of the screening exercise, the following decisions might be taken:

1. An impact assessment specifically for World Heritage is not required, and the project could proceed without it. This decision should be laid out in a brief screening report that comprehensively justifies the decision. Clear information and data should be provided in evidence to support this decision. The legal framework could still require an impact assessment to be carried out focusing on other values;
2. An impact assessment is required as the project might impact a World Heritage property. Any proposed or planned wind energy project with potential adverse impact on a World Heritage property requires an impact assessment with specific focus on identifying and assessing the potential impacts on its OUV;
3. A decision cannot be made based on the currently available information. In this case a list of the required information should be provided to the agency commissioning the screening and/or the impact assessment;
4. The screening process may conclude that the project proposal is unsuitable for development near a World Heritage property. Such conclusion is referred to as ‘no-go scenario’.

If a project proposal is radically changed during the impact assessment process, the screening might need to be repeated to reflect the latest changes (nevertheless, alternative options, like changes in the number of wind turbines, could be assessed within the IA document, and going back to screening is not necessary).

How does screening further relate to World Heritage requirements?

When a planned or proposed wind energy project is notified under paragraph 172 of the Operational Guidelines to UNESCO’s World Heritage Centre, stating that the project will have no adverse impact on the OUV of a World Heritage property, the resulting screening report is to be provided with the notification to justify this position.

Case studies

The current European Parliament and Council Directive on EIA (Directive 2011/92/EU amended by Directive 2014/52/EU) does not require a mandatory Environmental Impact Assessment (EIA) for wind power installations and projects, but it requires EU Member States to conduct an EIA for projects proposed in sensitive areas such as World Heritage properties.

Additionally, the directive requires EU Member States to base the decision on whether the commissioning of an EIA is needed or not on the screening’s outcomes.

See also:

Case study: Planning offshore wind turbines along the coast of Normandy (France, Fortifications of Vauban)

Once the need for the impact assessment has been identified, the scope of work is to be set out. Scoping defines what information needs to be studied in the impact assessment process. This phase aims to create a foundation for the impact assessment and as a preliminary exercise, identify possible significant impacts the proposed wind energy project might have on the OUV and attributes of a World Heritage property.

Considering all framing conditions, i.e., the OUV and attributes of the World Heritage property concerned, the characteristics of the proposed wind energy project and the type of potential impacts identified in the screening phase, the scoping study should investigate the following issues:

The result of the scoping exercise will be a report that also serves as Terms of Reference or guidelines for the realization of the impact assessment.

As the impact assessment itself, the scoping document should also be proportionate to the proposed project: whereas the construction of a few wind turbines may only require a short template to be completed with relevant information, a large and complex wind energy project would merit a thorough and detailed scoping report.

The suggested content of a general scoping report can be found in Guidance and Toolkit for Impact Assessments in a World Heritage Context.

➔ See also Note 4.

Why the scoping report is a crucial document in the impact assessment process?

A scoping report may confirm the results of the screening process but may also result in the definition of further options. If any potential impact to a World Heritage property is ruled out there may not be a need after all for a full impact assessment.

In other cases, if the ascertained impacts for the proposed wind energy project seem to be so significant that they imply its clear incompatibility with World Heritage, the project needs to be reconsidered or even abandoned. In both cases, an exhaustive explanation should be provided in the scoping report.

The baseline assessment aims at compiling a comprehensive overview of the current condition and state of conservation of the World Heritage property that is in the focus of the impact assessment.

It allows understanding the possible impacts of the proposed wind energy project by comparing its foreseeable future state with and without the planned project.

The scoping stage of the impact assessment identified the information needed for the baseline assessment, which then need to analyse and describe the current status of the World Heritage property’s OUV, attributes and other values.

A baseline assessment consists of three key elements:

1. Describing the past, present and likely future baseline

Analysing the Statement of Outstanding Universal Value

In the World Heritage context, the Statement of Outstanding Universal Value (SOUV – or the Retrospective Statement of Outstanding Universal Value) forms the basis of the impact assessment process, and it is one of the parameters against which impacts should be identified, assessed and evaluated. (SOUVs are usually formulated in a generic way that is often not detailed enough to fully satisfy the impact assessment. The nomination dossier prepared by a State Party for proposing the inscription of a site on the World Heritage List, the management plan and other documents that may have been produced by the management of the property or by research entities are therefore useful sources of information in addition to the SOUV). Nevertheless, if these documents do not provide satisfactory depth and detail of relevant information, it might be necessary to conduct an in-depth and structured assessment of the OUV which can include:

• The identification of attributes – including features and processes – conveying the OUV and other heritage values (especially the ones that support the OUV);
• A map locating the identified attributes – to define the geographical area of the assessment, one must cross-check the location of attributes with the potential area of influence of the proposed project.

➔ See also in World Heritage Essentials and Note 1.

Collecting existing data and information

After the analyses of the SOUV and the identification of attributes, the assessment should look at identifying attributes, features and processes conveying other heritage values of national, regional and local significance.

Data and information about the property, the OUV and other values can be collected from a variety of documents, for example:

• Statement of Outstanding Universal Value;
• Nomination dossier for the inscription of the property on the World Heritage List;
• Information concerning all international, national and local heritage designations protecting the property in question;
• World Heritage Committee decisions’
• Advisory Bodies’ evaluations, including Technical Reviews, and World Heritage related mission reports;
• State of Conservation reports;
• Answers to the Periodic Reporting questionnaires;
• Existing management plans or documented management systems;
• Monitoring data and reports (i.e., monitoring of key species and key habitats, monitoring reports referring to the implementation of conservation and management plans or strategies);
• Value mapping reports;
• Feasibility studies;
• Historic documents (including photographs, personal accounts and others),
• Relevant research results (publications, academic papers, etc.).

Many of these documents are available on the UNESCO World Heritage Centre website, on the national websites related to World Heritage properties of a country or maybe accessible through the site management organization.

➔ See also Note 1 and Note 2.

Further possible sources are provided in the Guidance and Toolkit for Impact Assessments in a World Heritage Context.

This expanded data collection provides the possibility to identify any missing data or information that will need to be collected, researched, reviewed, or analysed as part of the baseline study.

2. Carrying out additional studies

The baseline study will focus on collecting and analysing missing quantitative and qualitative data and information that will be essential for continuing the impact assessment process. This could consist of a series of individual and topic-specific studies focusing on identifying and exploring aspects of a World Heritage property’s multi-layered significance as related to the potential impacts of the planned wind energy project.

It may further consist in specific studies needed to better inform the impact assessment process, for example, wind resource assessments, visual assessments, studies concerning possible seasonal patterns and others. This is an iterative process as new information might be needed throughout the impact assessment process. Thus, the baseline assessment needs to be carried out in a flexible manner, allowing for new information to be collected and integrated in the assessment throughout the process.

➔ See Checklist 2.

A baseline study should be carried out considering a defined geographical area and timeframe. Particular attention should be paid to identifying possible seasonal and daytime/ night-time patterns like different life phases of the wind energy project, migratory phenomena, agricultural cycles, weather patterns, blooming timeframes, and others.

3.Understanding the legal framework and the management system of the heritage place

The analysis of the policy context, the governance and management system of the World Heritage property and its wider setting has the potential to support and improve the impact assessment process. This step can offer a good understanding of how the international, regional, national, and local management and governance framework operate and interact, offering the chance to further understand how the property might be impacted by the proposed wind energy project.

Within the scope of the baseline study, this step aims to:

• Understand the different international (for example, in addition to being inscribed on the World Heritage List, a World Heritage property can also be a UNESCO biosphere reserve), national and local natural and cultural heritage designations as well as nature designations in place at the concerned property;
• Identify possible weaknesses or limits of the existing management system which could enhance the negative impacts of the proposed wind energy projects (i.e., lack of maintenance, lack of understanding of the property’s multi-layered values in the management system of the property and others);
• Identify which management and monitoring mechanisms could support the implementation of the recommendations of the impact assessment (i.e., new indicators be developed for monitoring impacts deriving from the proposed wind energy project);
• Improve the understanding of the property’s rights-holders and stakeholders and who should or could be involved in different steps of the impact assessment process (i.e., if it had not already been happened, sending notification about the proposed wind energy project to the UNESCO World Heritage Centre).

How to handle ‘change’ in a World Heritage context?

Many World Heritage properties are dynamic places in which change is likely to have already happened due to ongoing natural processes or could happen because of future trends (for example, climate change) that will take place independently from the development of the proposed project. This is especially the case for natural World Heritage properties. Nevertheless, the acceptable level of change depends on the characteristic of a property, directly related to its OUV.

The baseline study should capture this change and it should understand what impacts might have already occurred and what future trends might impact the World Heritage property in future years.

1. Description of the proposed project

A thorough understanding of the proposed wind energy project is needed to adequately identify and evaluate the possible impacts it may have. This analysis builds on the information collected during the Screening and Scoping phases but now examines the details of the proposed wind energy project and project alternatives identified in the scoping report.

It is important to ensure that the wind energy project is understood in detail, including:

• The location of all elements of the proposed wind energy project and their relationship to the World Heritage property;
• The description of all technical elements that are part of the proposed project (for example, wind turbines, sub-stations, access roads, grid connection and other ancillary infrastructure);
• The details of all phases of the project lifecycle (planning, commissioning, operating and maintenance, and end-of-life strategies – lifetime extension, repowering, decommissioning).

A first approach to the definition of the area of interest of the assessment could be based on a map overlapping different layers or information, for example:

• Attributes conveying OUV and their relationship with one another;
• Attributes, features and processes conveying other heritage values;
• Location of the different elements of the proposed wind energy project, etc.

➔ See Checklist 3for project description.

Why the description of the project and its alternatives is of particular importance?

This phase is particularly important as it allows describing the proposed wind energy project in a comprehensively in the final impact assessment report. It is advisable to describe the proposal in clear and accessible language that can be easily understood by both technical and non-technical readers. This will allow all rights-holders and other stakeholders to easily comprehend and navigate through the information.

2. Alternatives to the proposed wind energy project

As the screening, scoping and baseline assessment elements of the impact assessment already provide a comprehensible picture about the World Heritage property (both concerning its geographical location, its characteristics and values, and the potential or identified sensitive areas), alternatives to certain aspects of the project might need to be considered, primarily if potential adverse impacts have already identified. An early identification of alternatives to the proposal allows the options to be discussed and considered when it is still possible to influence the planning decisions (saving therefore, time and financial resources for the project proponents).

The exploration of alternatives in case of potential negative impacts of the original proposal may lead to the revision of certain aspects of the project, or if no feasible alternatives can be proposed, the abandonment of the proposal in this early stage.

Aspects of the wind energy projects where alternatives could typically need to be identified:

• Alternative location of wind turbines and ancillary facilities (i.e., substations, transformer, cables, construction and maintenance roads);
• Alternative type and layout of wind turbines (i.e., foundation type, total height, density);
• Additional elements to the project that might avoid potential negative impacts (i.e., a pre-established maintenance schedule that ensures the undisturbed recreation period of marine species).

The Guidance and Toolkit for Impact Assessments in a World Heritage Context advises the alternatives to be considered in the three following steps:

1. Identification of reasonable alternatives, in line with the ‘Alternatives hierarchy’;
2. Assessment and comparison of alternatives;
3. Explanation of the choice of the preferred alternative.

Further advice related to identifying project alternatives

The identification of technically feasible and economically viable alternatives needs to focus on avoiding adverse impacts on the World Heritage property’s OUV (and preferably on other values of the site) in question.

Defining the geographical area and the area of interest of the proposed project to be considered by the impact assessment on a map together with the map of the World Heritage property (including its buffer zone and wider setting), could enhance the identification of project alternatives, as described in this step.

To be able to have the possibility to consider all alternatives, close consultation is advised to take place with the organizations/authorities in charge of protecting and managing the World Heritage property and with right-holders and other stakeholders.

The identification and prediction of impacts are at the core of impact assessments. This step foresees the identification and prediction of the likely negative and positive impacts that could occur with the development of the proposed wind energy project or of the identified alternative(s).

1. Identification of impacts

In the World Heritage context, the impact assessment process focuses specifically on identifying and understanding what would happen to the attributes conveying the OUV if a proposed project was developed inside or nearby a World Heritage property. While, in general terms, an impact can be positive or negative and it can affect many different aspects of a place: the biophysical environment, ecology, culture and cultural heritage, health, socioeconomics, views, auditory and others; in the World Heritage context the impact is rather neutral (when there is no impact) or measured on a negative scale.

The identification of impacts related to a wind energy project (including those from ancillary facilities and infrastructure) focuses on understanding the likely effects of the proposed wind energy project on the tangible and intangible attributes conveying OUV and other values. During the identification of impacts on the OUV, the area of the property should not be considered in isolation, but in interconnection with its buffer zone and wider setting.

Impacts of wind energy projects (as many other types of projects) can be rather diverse by nature and may occur at any stage of the proposed project. For this reason, the impacts of a wind energy project need to be examined for the whole project lifecycle (for example, increased noise pollution and disturbance can be experienced during the construction phase while other impacts may occur only seasonally, like collisions of migratory birds with wind turbines and visual impacts will occur after construction). Actions from the proposed project, therefore, could have short-term, medium-term, and long-term effects, as well as permanent and temporary effects. Effects of the action could impact the area of the property, its buffer zone, or its wider setting, but the impacts will need to be assessed in relation to the OUV of the World Heritage property, no matter where their effect is located.

See overview of "potential impacts of wind energy projects on the OUV of World Heritage properties" in Impacts of Wind Energy projects and their assessment.

Impacts of a proposed wind energy project could be very complex and professional judgement will be needed in their identification. Useful tools in this process to be used may be:

• Overlay maps: colour-coded or otherwise differentiated plans that show the physical extent and different elements of a wind energy project that could be compared with areas of World Heritage properties (area of the property, its buffer zone and its wider setting) and the attributes that convey their OUV;
• Checklists: that may be part of national guidance documents concerning the likely impacts of wind farms;
• Matrix/Matrices: these may be created with the attributes that convey the OUV of World Heritage properties on one axis and elements of the proposed wind energy project on the other axis in order to examine the potential interaction between the two;
• Network diagrams: could provide visualization of links between the elements of the proposed wind energy project and its impact on the attributes that convey the OUV of World Heritage properties.

Within the impact assessment process, three main types of impacts will need to be considered:

• Direct impacts, which are the result of a cause-and-effect relationship between the wind energy project and the OUV of a World Heritage property.
  For example:
  • The permanent removal and destruction of otherwise undisturbed, buried archaeological sites and features through preliminary excavation needed in advance of the construction of the foundation of wind turbines;
  • Change of historic/traditional land division pattern and land use from the placement of a wind farm; habitat loss and wildlife displacement by disturbance of migratory bird species due to collisions with wind turbines;
  • Changes in the perception of the landscape and disturbance of key vistas or panoramas of a cultural site with visual values due to placement of wind turbines or wind farms in important or key panoramic areas.
• Indirect impacts (or secondary impacts and in many cases induced impacts) which are not a direct result of the wind energy project but are the result of its actions through a more complex pathway (they could occur later in time or are removed from the action location).
  For example:
  • Changes in sediment erosion or deposition outside a World Heritage property caused by increased navigation for the maintenance of offshore wind turbines, which has a negative effect on the OUV of the World Heritage property;
  • Increased development in an area that acquired access as a result of building a maintenance road for a wind energy park, resulting in increased development that induces negative impacts on the OUV of a World Heritage property.

• Cumulative impacts, which are the result of the combined impact of the proposed project actions together with impacts derived from past, present, or foreseeable other projects.
  For example: 

• • An existing wind farm in the wider setting of a World Heritage property could already have a small/moderate negative impact on its OUV; when more wind turbines are proposed as an extension of the wind farm in a location that includes key vistas for the property, the negative impacts of the existing wind farm and the proposed additional wind turbines reinforce each other and add up to cumulative impacts.

Nevertheless, it is to be noted that no matter which type of the above three impacts is identified during the impact assessment, if it affects negatively the OUV of a World Heritage property, the appropriate actions should be taken for avoiding (or if it is an option) mitigating the identified negative impact(s).

➔ See Note 5 and Note 6 for a detailed explanation of analysing cumulative impacts and the special cases when visual impacts are relevant.

2. Prediction of impacts

An informed prediction can be made about the likely scale and nature of the potential impacts that had been identified in relation to a proposed wind energy project. This prediction is a technical analysis based on all available information and refers to the baseline condition of the World Heritage property (➔ See the step 3: "Baseline assessment" ). It aims at providing a consolidated base for an informed judgment about the compatibility of a proposed wind energy project with the protection of a World Heritage property and seeks to feed information into the design and planning steps of the project.

The methodology for predicting impacts will depend both on the characteristic of the proposed project, the predicted impacts, as well as the characteristic of a World Heritage property concerning its OUV and attributes. The characteristic of potential impacts might relate to their magnitude, type, extent, duration, frequency, reversibility, likelihood, etc. In some cases, the impacts may be quantifiable, in other cases, a narrative description might be better suited for their description.

➔ See in general World Heritage Essentials, the "Overview of potential impacts of wind energy projects on the OUV of World Heritage properties" in Impacts of Wind Energy projects and their assessment, Note 5 and Note 6.

Of the several ways to predict impacts, the Guidance and Toolkit for Impact Assessments in a World Heritage Context outlines three main techniques:

1. Quantitative analysis that is based on the calculation of impacts using collected baseline data and an understanding of the proposed actions. (It also proposes to develop models to understand indirect and cumulative impacts) – it is to be noted that this technique might work only for World Heritage properties with an OUV that is specifically suited for this approach;
2. Professional judgment of specialists with consolidated experience in the assessment and analysis of impacts caused by wind energy projects who can offer a more qualitative estimate based on similar projects proposed an/or implemented in the same/similar region with the same/similar context – this technique should be favoured above all the others while carrying out an impact assessment for a proposed project that concerns a World Heritage property;
3. Using case studies by examining similar projects developed in comparable contexts, especially if monitoring data is available – this technique should only be considered as an additional tool for carrying out an impact assessment for a proposed project that concerns a World Heritage property.

It is important that impacts are estimated and compared in a transparent and systematic manner, and that the final report clearly sets out the methodology and parameters applied in the study to ensure both an accurate readability of the results and the possibility to verify and review the predictions of possible impacts that have been identified.

In some cases, an impact assessment cannot be based on exact data and information because not all project information may be available or detailed enough. In these cases, the proponent should be asked for more detailed information about the project and until that is available for assessment, a useful methodology might be to apply the ‘precautionary principle’ and look at multiple alternatives, including best- and worst- case predictions (concerning number of wind turbines, their maximum heights planned, etc.).

➔ See also "Precautionary principle" in the Screening step.

Additional information concerning the quantitative analyses

Whenever using the quantitative analyses method for predicting impacts, a clear comparison between the likely future with and without the proposed wind energy project and the alternative project option(s) will need to be tackled.

When quantitative analyses cannot provide exact numbers, impacts might be qualified as high, medium, or low in a grid format for the comparison of different scenarios. Nevertheless, this is to be considered a less accurate and systematic methodology.

Once impacts have been identified and predicted, the next step is to evaluate the degree of impacts and whether they are considered acceptable or not. This is a key step in the impact assessment process as the results may be directly translated into recommendations for decision-makers concerning the wind energy project. In the context of a World Heritage property, this step focuses on the evaluation of the significance and characteristics of an identified impact on the individual attributes conveying the OUV of a World Heritage property. Nevertheless, overall impacts on the OUV and other values will also need to be assessed.

➔ See Note 1 and the step 3 "Baseline Assessment".

How can impacts be evaluated?

There are multiple methodologies for the evaluation of impacts and several ways of presenting them such as matrixes, colour-codes and tabular visualizations of impacts. An appropriate methodology should be selected according to the nature of the proposed project and the types of impacts predicted.

An overview of evaluation methods is presented in the Guidance and Toolkit for Impact Assessments in a World Heritage Context.

➔ See also Note 4 and the overview "for potential impacts of wind energy projects on the OUV of World Heritage propreties" in Impacts of Wind Energy projects and their assessment.

For more detailed information related to assessing potential visual impacts, see Note 5 and for cumulative impacts see Note 6.

The impacts of a wind energy project need to be evaluated with regard to all project phases (considering each step in the project lifecycle), as different impacts might occur at each phase (design and planning, construction, operation or end-of-life phase).

For example, the construction of wind turbines could cause high level impacts that need to be avoided or mitigated, but these will be redundant later during operation and maintenance phases, which might create other impacts.

1. Negative impacts

If the proposed wind energy project will potentially have negative impacts on the OUV, three conclusions could be reached as a result of the evaluation:

1. The negative impacts for the OUV overall would stay at a negligible level, therefore, the project could go ahead, but the low-level negative impacts will need to be mitigated if possible;
2. The negative impacts would be significant on the OUV overall, but with avoidance and mitigation measures, the level of negative impacts could be eliminated and minimized to an acceptable degree;
3. The negative impacts would be significant on the OUV overall, and no feasible avoidance or mitigation measures were found, therefore the proposed wind energy project should not proceed.

2. Positive impacts

Positive impacts of the proposed wind energy project will also need to be highlighted as part of the assessment evaluation process. Positive impacts (identified, predicted and evaluated) are fundamental to understand the project itself and its possible relevance to rights-holders and stakeholders.

Positive impacts of the proposed wind energy project should primarily be considered against the objectives set for the proposed actions, and the following conclusions could be reached as a result of their evaluation:

1. The positive impact of the proposed project is relevant and also beneficial for the World Heritage property, therefore, raises no concerns;
2. The positive impact described in item 1. could be enhanced if another project alternative or project design is selected;
3. The positive impact does not reach objectives set for the proposed action (the generated energy is not sufficient, not cost effective, etc.), therefore, the proposed action or the project itself should not proceed;
4. In case the positive impact set for the proposed action of the wind energy project is not related or relevant for the World Heritage property (for example, the operation will contribute to reducing the carbon footprint) the acceptance of that project aspect/action will depend on its impact on the OUV overall.

If the impact is neutral or positive on the OUV, it can proceed. However, if it has a negative impact on the OUV overall (as for example, the wind turbines will pose an adverse visual impact for a cultural landscape with important visual values) these will need to be avoided (for example, the wind turbines or a problematic transformer station be moved further from the boundaries of a site) or mitigated (for example, using subsoil cables for transmitting electricity from the wind farm), otherwise this aspect of the proposal or the project itself is not to proceed.

The evaluation of impacts and their significance on the attributes and the OUV overall, will lead to the need to explore:

1. Measures to avoid or mitigate negative impacts to an acceptable level;
2. Ways to enhance the identified positive impacts.

In the World Heritage context, the positive impacts must not be weighed up against any negative impact the proposed project might have on the OUV of a World Heritage property. As the OUV is irreplaceable, offsetting is not an option.

A wind energy project with a significant adverse impact on the OUV of a World Heritage property should be considered unsuitable and should not be granted permission. Any mitigation attempts to balance out potential negative impacts on the OUV with otherwise positive impacts reflects an improper approach and is unacceptable from a World Heritage protection point of view.

Should not all wind energy project be considered as positive by default?

As wind energy installations are linked to renewable energy projects, they could be considered by default as initiatives with an overall positive impact in terms of their contribution to combating the ongoing climate emergency and their role in achieving the 2030 Sustainable Development Goals. However, due to the Outstanding Universal Value of World Heritage properties, negative impacts of planned installations on these areas should be avoided where and whenever possible, and alternatives should always be investigated through an impact assessment process.

The impact assessment process will need to assess the consequences of a proposed wind energy project from all relevant aspects, including its benefits and positive impacts. Wider benefits of these projects could include social aspects, such as access to clean energy, opportunities for local employment and reduced energy prices for local communities. Nevertheless, these benefits should not be achieved at the cost of negative impacts on World Heritage properties. Alternative solutions can be found, for example by finding other locations for the whole wind farm or its ancillary facilities, or by reducing their size and scale.

The impact assessment process should identify and evaluate the possible negative and positive impacts of the proposed wind energy project and clearly state which ones are considered to be acceptable or not acceptable with regard impacts on the OUV of the property, its other values and in relation to rights-holders and local communities.

1. Mitigation of specific negative impacts

In the World Heritage context, a case-by-case assessment is needed to consider how to proceed if potential negative impacts have been identified on values of a World Heritage property. Some attributes that convey the OUV might not be particularly sensitive to impacts of a proposed wind energy project and certain very low impacts might not need mitigation. Other attributes might be more sensitive to the same type of impact, depending on the characteristics of the OUV that is unique for all World Heritage properties. In these cases, mitigation should be considered to avoid or minimize the negative impacts.

Concerning impacts on values that are not part of the OUV and attributes of the World Heritage property, the mitigation measures might take a less strict approach, especially when these would help safeguard the broader societal values derived from the project.

The proposed project-specific mitigation measures, therefore, need to consider a matrix that includes both specificities of the OUV, the attributes that convey the OUV and the other values, as well as the elements and characteristics of impacts derived from the proposed wind energy project (and its different project phases).

Please see the detailed description of the ‘Mitigation hierarchy’ in the Guidance and Toolkit for Impact Assessments in a World Heritage Context.

From the ‘Mitigation hierarchy’ the following mitigation measures are appropriate for a World Heritage property in relation to handling negative impacts:

• avoid = measures that avoid creating the impact on the OUV and attributes of a property;
• minimize = making changes to ensure that the project element of concern is revised and reduced to a level where it no longer poses threat to values (it is important to note that ‘minimizing’ is not a synonym of ‘reducing’, which implies that the negative impact is reduced but not necessarily to the level where it does not still have a negative impact).

See also the Guidance and Toolkit for Impact Assessments in a World Heritage Context for a more detailed explanation concerning the mitigation measures.

Examples for mitigating negative impacts

Avoidance:

• changing the location of wind turbines or the wind farm to less-sensitive areas, avoiding areas of archaeological interest and/or potential key vistas/historic panoramas or migratory routes.

Minimizing:

• reducing the number and/or the height/other dimension of wind turbines, so that they have no negative visual impact related to the OUV;
• re-designing project components, for example, sub-stations and access roads so that they do not pose a negative impact for the OUV of the World Heritage property;
• reducing noise disturbance. the noise, generated by the wind turbines, the sub stations or any other ancillary facility is managed until it is at such a low level that it no longer causes disturbance in relation to the OUV (like for nesting birds).

Rectifying, reducing or offsetting negative impacts

Rectifying and reducing negative impacts, in general, are not considered to be suitable tools for mitigating negative impacts in the World Heritage context. Nevertheless, these methods might be used for mitigating negative impacts on other values that are not related to the OUV and attributes of a World Heritage property.

To rectify means: rehabilitating and/or restoring the degradation caused by a specific action of the proposed project.

This solution is acceptable only if within a reasonable timeframe, there are no foreseen negative impacts on the OUV overall.

As an example:

• rehabilitate the landscape after the construction phase of the wind energy infrastructure that involves large earthworks, intensified traffic of heavy machinery, etc.

Overall negative impacts of a wind energy project could not be rectified by calculating with rehabilitation works after the licensing period of operation (20 to 30 years) expires and potentially a wind farm gets dismantled and the land it occupies gets rehabilitated.

Reducing negative impacts encompasses actions that aim to decrease its impact level, but not to a level where there would be no noticeable impact.

As an example:

• noise level of the wind turbines might be reduced, but not to a level where there would be no negative impact to sensitive species that are part of the OUV of a World Heritage property;
• the density and size of the wind turbines are reduced within a planned wind farm, but they would still be visually intrusive for the integrity of a World Heritage property.

Offsetting means compensating for any negative impact that could not be avoided, minimized, rectified or reduced through providing positive measures.

As an example:

• after every hectare of wind energy development in a highly sensitive habitat (like intact grasslands) within a World Heritage property and its buffer zone is offset by restoring a hectare of key habitat elsewhere by the developer.

As the OUV is irreplaceable, this method for mitigating negative impacts is unacceptable in the World Heritage context.

Case study

Specific guidance on the identification, evaluation and mitigation of impacts by wind energy farms and installations is provided by IUCN and The Biodiversity Consultancy in the resource manual Mitigating Biodiversity Impacts Associated with Solar and Wind Energy. The document offers step-by-step guidance in the identification and assessment of impacts throughout the project lifecycle – early planning, project design, construction, operations, closure and decommissioning or repowering – of both onshore and offshore wind and solar farms.

Please note that the International Union for Conservation of Nature (IUCN), an advisory body of the World Heritage Committee considers large- and industrial-scale infrastructure incompatible with the objectives and the conservation outcomes of Natural World Heritage properties.

2. Developing or enhancing positive impacts

As wind energy projects by default should have a positive impact in relation to the 2030 Sustainable Development Goals and reducing the negative impacts of climate change, the positive impacts of these proposals need to be at the focus of the entire impact assessment process and ensure that the positive elements of the wind energy projects are not lost in the project development phase.

As Target 7.2 of SDG Goal 7 aims by 2030 to “increase substantially the share of renewable energy in the global energy mix”, Target 11.4 of SDG 11 advocates to “Protect the world's cultural and natural heritage”. Therefore, a feasible balance should be found by creative problem-solving approach, to meet both interests.

Examples for enhancement of positive impacts

Examples for enhancement of positive impacts:

• replacing a coal fired energy plant that provides electricity for a region with wind farms;
• positioning a wind farm on contaminated land and remediating it as part of the project;
• creating a self-sufficient renewable energy system for a World Heritage site management organization operating in a remote area.

3. Ensuring the implementation of mitigation and enhancement measures

A key concern for mitigation and enhancement measures is ensuring their effective implementation beyond the impact assessment process. They might be used by the relevant authority as conditions in the permit and licensing documents for the construction and operation of the wind energy facility.

In any case, the mitigation and enhancement measures should become a coherent part of the wind energy project cycle (from planning to end of life options) and a clear framework needs to be provided to ensure that the following aspects are taken care of:

• the set of actions and measures are agreed and approved;
• responsible are appointed for carrying out
  • the mitigation measures/activities;
  • the monitoring and supervision of implementing the measures;
• the cost bearers are appointed, and the costs are estimated;
• a timeframe is set and approved for the actions, and what in which phase of the project it needs to be carried out.

The above aspects become even more important if the mitigation and enhancement measures are not directly linked to the planning and construction phase, but rather the maintenance or the end-of-life actions of the wind energy project.

Following-up mitigation measures

The effective implementation of mitigation measures requires the establishment of clear agreements with the wind energy developer. The implementation of mitigation measures should be included in management and operational documents dealing with the construction phase, the long-term operation of the wind energy project and responsibilities concerning decommissioning once the lifecycle is exhausted. All these pieces of information should be an integral part of the licensing documents, the Environmental and Social Management Plan (that guides actions on the ground when the contractor implements the actions) and other relevant project management plans. These documents should be available for all relevant parties, throughout the operational phase of wind energy facilities.

With regard to the processes in the impact assessment concerning the mitigation of negative impacts and the development of project alternatives, the evaluation of impacts can be and if needed should be an iterative process which is repeated if new information becomes available or if the proposed project is revised (to assess the impact of alternative project option(s).

This step will have to be repeated until all potential negative impacts are avoided or mitigated or a ‘no project‘ option is considered instead, if residual negative impacts on the OUV overall remain, even after mitigation.

It is important to keep in mind that the evaluation of impacts is not the end of the process but rather the key moment of interaction with decision-makers. The results should be formulated in a way to clearly define the possible impacts stemming from the project and the possible mitigation measures. If the project is considered to have no negative impact the recommendation should consider the definition of elements and key considerations to be included in the licensing process.

Involvement of rights-holders and other stakeholders

The participation of right-holders, local communities and other stakeholders is key throughout an impact assessment. It is, therefore, important to engage with them in this step as well, as rights-holders and other stakeholders should have the chance to express their perspectives and understand the potential impacts of the proposed project on their livelihood. They will also need to be consulted while considering mitigation measures and/or project alternatives.

To be effective and to fulfil its objectives, an impact assessment process should result in a report made available for all interested parties.

It is important to ensure that clear information is provided on the methodology employed for the assessment and clear conclusions are conveyed. It is equally important that the language of the report is clear for both the decision-makers and for right-holders and other stakeholders concerning the analyses and the recommendations as well. The level of detail needed, and the amount of information included in the report will depend on the complexity of the proposed wind energy project.

The report should use and reflect the information, analyses and assessment carried out during the impact assessment process. Within this frame, it will need to focus primarily on:

• providing all relevant information related to the World Heritage property in question (OUV, attributes, territorial aspects, and other relevant cultural and natural heritage values, etc.);
• the impacts of the proposed wind energy project on the attributes of the OUV and on the other values;
• the overall impact of the proposed project on the OUV of the property;
• clear conclusions and recommendations (related also to mitigation measure, project alternatives or the ‘no project’ option).

The report structure is advised to follow the step-by-step development of the impact assessment process. Nevertheless, impact assessment reports might need to follow format- or content-wise national regulations or guidance documents.

➔ See also Checklist 4.

Ensure that World Heritage is addressed in the report

An impact assessment process for the identification and evaluation of the impacts of a wind energy project on a World Heritage property is often part of a wider Environmental Impact Assessment (EIA) or Environmental and Social Impact Assessment (ESIA) that is normally a requirement and obligation for project proponents under the national legal framework (this is the case for all EU Member States).

In these cases, it is highly important that the assessment and also the report adequately address the impacts on the OUV and attributes of the World Heritage property in question.

The aim of reviewing the report is to determine whether the applied assessment methodology and the outcomes are adequate, if it has fully complied both with the relevant legal and professional framework and the established Terms of Reference, and moreover, if it is fit for purpose in terms of transparency and usability.

The review process it is an important step to ensure quality control; it can be conducted in different ways and at multiple levels. It is often mandatory, especially in countries, which legislation includes an Environmental (and Social) Impact Assessment (EIA or ESIA) process. The review is often carried out by a government agency with a specific mandate or by an external independent reviewer team through a transparent process. The review of the report is especially important when the impact assessment is carried out under a contract linked with the project proponent and/or by other interested parties.

The review must provide a clear description of the assessment process, the information used, and its final conclusions and recommendations. Every effort should be made to ensure that:

1. The report and its conclusions are in line with existing national legislation and policies and international agreements;
2. The impact assessment process and report have fulfilled the Terms of Reference established by the commissioner or the relevant authority (it is advised that the Terms of Reference be checked by the relevant authorities prior to its commissioning);
3. The report addresses all the issues raised in the ‘Scoping report‘;
4. The report adequately addresses the World Heritage context;
5. The conclusions of the impact assessment report are in line with the established methodology of the assessment and the findings are logical results of the process.

In general terms, the review of an impact assessment will result in one of the two following outcomes:

1. The quality (including the baseline data, methodology and the report) of the impact assessment is adequate and fit for purpose.
2. The quality of the impact assessment and the report is insufficient, and the report should be revised (additional information is needed or a revised methodology should be applied, etc.).

Making the report available for rights-holders and other stakeholders and UNESCO

Rights-holders and stakeholders

The report should also be made available for rights-holders and other stakeholders to allow them to comment and check how their views and comments have been taken into account and how these influenced the project proposal and the assessment.

In some countries, the report is made available for public review (for example, through an online platform), allowing further room for comments.

Sending the report to UNESCO

As already highlighted in other parts of this guidance, when a proposed wind energy project has an impact on the OUV of a World Heritage property, a notification under paragraph 172 of the Operational Guidelines is to be sent by the State Party to UNESCO’s World Heritage Centre. The report of the impact assessment, in the reviewing stage, is a useful annex to this notification that allows both the World Heritage Centre and the Advisory Bodies to carry out their evaluation on the proposal and the report itself and provide feedback to the State Party (often in the form of a Technical Review prepared by the Advisory Bodies, ICOMOS or IUCN).

Decisions are made throughout the impact assessment process as described in steps 1 to 8. Nevertheless, if the wind energy project proposal is taken forward until the impact assessment report and if the proponent has not decided to change or redesign important elements of the project that require to return to steps prior to the impact assessment, the report is handed over with the other planning documents to the relevant national/regional/local authorities for a formal decision under the legal framework.

The final impact assessment report provides decision-makers with clear conclusions and recommendations. Based on those recommendations and the evidence that led to them, the relevant national, regional or local authorities should consider one of these three options:

1. The proposed wind energy project is approved as its construction does not negatively impact the OUV of a World Heritage property. However, the approval might include specific conditions and requirements for mitigation measures;
2. Approval is postponed, for example, in cases when the impact assessment has highlighted the need to consider redesigning the proposed project and/or if more information is needed before a decision can be taken;
3. The proposed wind energy project is rejected in the case the assessment has identified considerable negative impacts of the proposed wind energy project on the OUV of a World Heritage property.

How the impact assessment result relates to decision-making of the UNESCO World Heritage Committee?

Please note that the result of an impact assessment (the report) might also be made available for the World Heritage Committee to help the Committee’s decision-making in relation to the obligations of States Parties under the World Heritage Convention.

As formal decisions concerning a wind energy project are in most cases legally binding, if negative impacts of a wind energy project are discovered after a proposed project receives approval from the national/regional/local authorities, it creates a situation that is hard to resolve. This might be the case if an impact assessment does not consider the impacts of the proposed project on the OUV of a World Heritage property, which can happen when the proposal is not within the boundaries of the property or its buffer zone, but also if the methodology followed for assessing impacts were inadequate.

The World Heritage Committee might regard the approved project incompatible with fulfilling the obligations of a State Party under the World Heritage Convention and request the State Party to rectify the situation (even if the project has been implemented). On one hand, this may lead to national authorities facing lengthy legal procedures and having to pay the project developer financial compensation. On the other hand, if the proposed or implemented project poses potential or ascertained threat for the OUV of the World Heritage property, it may lead to its inscription on the List of World Heritage in Danger (See paragraphs 177-191 of the Operational Guidelines) or its deletion from the World Heritage List (See paragraphs 192 to198 of the Operational Guidelines).

When a wind energy project is approved and can be implemented, the information and recommendations that result from the impact assessment process should be incorporated in the relevant project documentation and contracts, such as the licensing agreement and should be part of an Environmental and Social Management Plan (ESMP). The impact assessment report itself will be the basis to develop a set of follow-up actions.

The complexity of the required mitigation and enhancement measures and other follow-up actions will also depend on the level and complexity of the wind energy project. While a small project might only require the preparation of a list of measures and actions needed, a major, large-scale wind energy project will require the drawing up of the ESMP. The relevant heritage authorities and experts from the impact assessment will need to be consulted in the development of this document, which will become part of the contract documentation of the project.

The mitigation and enhancement measures and other follow-up actions are to be implemented and monitored together with the wind energy project. The follow-up plan or the ESMP should include clear monitoring procedures to ensure that the recommendations of the impact assessment report are adequately and effectively implemented and that no unexpected further impacts arise from the project, which may need immediate managing.

The implementation of the follow-up phase needs to be ensured primarily by the project developer and the wind energy site manager. However, it also needs the supervision (compliance monitoring, inspection and enforcement) of the responsible governmental or institutional bodies on the national/regional/local level (environmental and heritage authorities) and the management team of the World Heritage property to ensure that during the implementation of the follow-up measures, the OUV of the World Heritage property is preserved. The National Focal Point for World Heritage is also expected to follow up on implementation of the World Heritage Committee Decisions and Recommendations of the Advisory Bodies in this regard.

The Guidance and Toolkit for Impact Assessments in a World Heritage Context includes a full set of follow-up activities. Please check these for developing measures in relation to wind energy projects.

What if changes are needed for a wind energy facility within its lifecycle?

Considering that a wind energy project may change during its lifecycle (i.e., due to changes in a country’s energy need, renewable energy strategies, policies and plans) so may change the originally planned end-of-life strategy of a wind energy facility. This could imply a decision to dismiss the decommissioning process in favour of repowering, often with the installation of technologically more advanced infrastructure: the enlargement of existing facilities or construction of new wind turbines, modern ancillary facilities, new access tracks to the wind farm site, etc.

In these cases, a new impact assessment process should be initiated to ensure that after its redesigning, the proposed new elements and the wind energy facility as a whole are adequately assessed before permission is granted. Furthermore, it should be ensured that it will not threaten the OUV of a World Heritage property.

This is a necessary exercise as during the years the context of a World Heritage property may also change, for example, through the construction of other wind farms or other types of projects in the surrounding areas. These may add up to impacts and call for the assessment of cumulative impacts.

If a wind energy project in any of its phases seems or proves to negatively affect the World Heritage property’s OUV (either due to inadequate follow up and implementation of the mitigation and enhancement measures, or due to unforeseen circumstances) if possible, the project element inducing the negative impact should be halted, the impact/damage needs to be assessed and appropriate actions (mitigation or other) need to be initiated or approved by the relevant national/regional/local authorities as well as the site management.

The needed actions might already be identified and included in the management systems in place (either the ESMP or the management system of the World Heritage property).

Monitoring the follow-up activities and measures

The monitoring in the follow-up phase will also allow the collection of information that could feed into enhancing the information related to the World Heritage property, its OUV and attributes, as well as its management system/management plan.

As an example:

• Collection of information about the attributes of World Heritage properties can be used to check against the baseline collected during the impact assessment;
• Monitoring the wind energy facility in use might provide new information related to the sensitivity of attributes or other information relevant for the baseline.

➔ See also 'Potential proactive actions' included in Protecting World Heritage in the context of the renewable energy transition.