Keywords

Landscape; perception; character; design composition

23.1 A Passion for Landscape

Most people are passionate about landscape, whether as a source of inspiration for paintings or poetry; as the backdrop of a favorite walk; providing the growing environment for food; to sustain animal livestock; as the setting of carefully crafted views; or simply as daily surroundings. Irrespective of whether the landscape has formal recognition as being of outstanding value or quality, with statutory protection, for example, as a National Scenic Area in Scotland, as an Area of Outstanding Natural Beauty in England or as a National Park (see Fig. 23.1), or whether it is fairly degraded land frequently found on the edge of our cities, changes in the landscape tend to invoke strong feelings and opinions in people.

In this chapter we will discuss how wind energy developments affect people’s perception of landscape and how the number, composition, and size of turbines (which make up a wind farm) influence this perception. We will discuss the meaning of landscape and consider how the development of wind farms in the landscape may affect the qualities and values that people attach to the landscape.

23.2 What Is Landscape?

Governments across the European Union have ratified the European Landscape Convention (ELC), which is designed to achieve improved approaches to the planning, management, and protection of landscapes throughout Europe. It has also put people at the heart of this process. The ELC defines landscape as: “an area, as perceived by people, whose character is the result of the action and interaction of natural and/or human factors” [1]. As quoted in the current UK Guidelines for Landscape and Visual Impact Assessment, “landscape is about the relationship between people and place. It provides the setting for our day-to-day lives. The term does not mean just special or designated landscapes and it does not only apply to the countryside” [2,3]. These descriptions confirm that landscape is important to people and therefore changes in the landscape may affect people in different ways.

Particularly in recent years, theories about the importance of landscape have evolved and the significance of the ELC definition is that it has moved thinking about landscape beyond the idea that landscape is only a matter of aesthetics and visual amenity. The ELC encourages a focus on landscape as a resource in its own right and not just on the setting for human activity (See Fig. 23.2). Understanding and evaluating landscape allows us to conceptualize our surroundings and consider the effects of introducing developments into our landscapes, and it can contribute to providing a spatial framework for managing landscape change. This enables informed discussion and debate about a wide range of environmental, land use, and development issues including wind farms.

23.3 Changing Landscape

The description of landscape in the ELC fully encompasses the changes that a landscape undergoes when humans live in it, aptly captured by Susan and Geoffrey Jellicoe in their book The Landscape of Man: “Throughout history men have moulded their environment to express or to symbolize ideas—power, order, comfort, harmony, pleasure, mystery” [4].

Landscapes are constantly changing as a result of human intervention, such as intensification of agriculture, felling of rainforests for cultivation, or loss of agricultural countryside to urban development, and importantly it is widely accepted that landscapes will change further through climate change (see Fig. 23.3). Some of our land will be lost to the sea, some parts of the world will become more arid, and other areas may become wetter as a result of natural processes and these changes to our landscapes are among the consequences of climate change that people have limited control over. Notably, however, other significant changes in landscapes will be the result of the measures we take to address climate change.

Drastically cutting CO₂ emissions by reducing reliance on fossil fuels is one of the primary measures to address climate change. This has led to governments across the world setting renewable energy targets to reduce CO₂ emission levels in accordance with the Kyoto protocol [5]. In many countries, the development, construction, and operation of wind farms, both on- and offshore, are part of the mix of measures taken to address climate change. Introducing a wind farm in any landscape or in the sea (located ‘inshore,’ i.e., within sight of the land) has effects on the views of the landscape and may affect the perception of the landscape and seascape character and thus the wind farm itself contributes to landscape change.

23.3.1 People’s Opinions

One of the most common comments made by local people who are consulted on a wind energy proposal in their local area is: “I am all in favour of renewable energy and wind farms but this is not the right place.” Given that the primary concern of most people with respect to wind farms is their effect on landscape, views, and visual amenity, government support or otherwise for this type of development has therefore increasingly become a political issue. This is in itself not unique, as other forms of energy generation invoke equally strong opinions, as may be illustrated by the prolonged debate about new nuclear power plants in the United Kingdom or about fracking.

Whilst wind turbines are seen by some people as sculptural objects in the landscape, others see them as industrial monstrosities. Irrespective of this, wind farms are not being constructed for artistic reasons, but are designed and built to generate electricity, and the form of the turbines is driven by aerodynamic rather than sculptural considerations. They may therefore be comparable in scale, but not in function, to large sculptures such as the Angel of the North, near Gateshead, United Kingdom (see Fig. 23.4).

Landscape architects recognize that any type of development leads to changes in the landscape and on views and visual amenity. Some of these changes resulting from development are very subtle or barely perceptible but other types of development lead to more substantive change in the landscape and in the perception of the landscape. The tall nature of modern wind turbines, currently up to 200 m tall for the largest turbines, and the associated movement of the rotating blades, means that they are potentially visible from great distances, in some landscapes and visibility conditions up to 50–60 km.

Landscape architects describe the likely change in landscape by using readily recognizable terminology that will resonate with most people. In order to explain varying degrees of wind energy developments in the landscape, different levels of development may be described as ‘landscape without wind farms,’ ‘landscape with occasional wind farms,’ ‘landscape with wind farms,’ and for the most developed landscapes with the term ‘wind farm landscape’ (see Fig. 23.5). Such terminology is not unique to wind energy development and may equally apply to, for example, coniferous forestry: ‘landscape without forest,’ ‘landscape with occasional forest,’ and ‘forest landscape.’

It is clear that landscapes are constantly changing, as a consequence of urban development, changes in farming practices, land use planning policies, and indeed as a consequence of wind farm development. Rather than ‘standing on the side lines,’ and reactively responding to the effects of wind farms, we need to continue to study the effects of wind farm developments on landscape, and proactively debate and decide which landscapes are more suitable and capable of accommodating wind energy development and which landscapes are more vulnerable to losing their unique qualities. In our view it is necessary and possible to ‘take control’ with respect to which landscape can accommodate wind farm developments, and to design how these landscapes may change in the future as a result of wind energy development.

23.4 Technological Advancement

It is thought that wind energy will make a substantial contribution to our energy supply in the (relatively) short term of the next 25–50 years. In this timescale it is possible that new technologies will come on stream that will replace on- and offshore wind, and ultimately lead to the removal of wind turbines from our landscape. There is plenty of evidence from history to demonstrate how the process of technological advancement led to the introduction and subsequent abandonment of power generation industries that have had a major effect on the landscape.

In the 20th century we have seen the effect of the transition of coal-fired power stations to gas-fired power stations. The introduction of a very large coal-fired power station near Didcot raised considerable landscape and visual concerns in 1965. Sue and Geoffrey Jellicoe wrote: “The cooling towers of Didcot Power Station, Berkshire, are symbolic of energy waste, destructive to the human scale and an intrusion into a famous rural vale that was almost universally resented” [4].

Wind energy has been harnessed for centuries with wind-driven mills draining the land in the Netherlands or milling grain into flour across the world. Many of these windmills are now listed and are protected as valued historic structures (see Fig. 23.6).

Electricity generating turbines are more recent and have become increasingly commonplace since the 1990s. Early turbines were relatively small, noisy, and inefficient with low-energy yields. In recent years, however, driven by the pressing need for more efficient sources of renewable energy, technological advancement has accelerated. Modern machines are considerably more efficient, with greater energy yield per unit of swept area, but this has also led to ever increasing height and size of both on shore and offshore wind turbines.

One of the first commercially developed wind farms in Scotland, Hagshaw Hill in South Lanarkshire, uses turbines with a hub height of 35 m and a rotor diameter of 41 m (therefore 55.5 m to blade tip) generating 600 kW per turbine (see also Fig. 23.7).

The recently installed Westerwind turbines near Urk in the Netherlands have a 135 m hub height and blades of 63 m length resulting in a tip height of 198 m, and can generate potentially 7.54 MW each. Notably part of the Westerwind development is what may be termed inshore with the turbines within the Zuiderzee, the large inland sea within the Netherlands. The inshore turbines of the Westerwind development are ‘only’ 165 m to tip high.

To date, the most commonly proposed commercial onshore wind turbine in the United Kingdom is in the order of 125–150 m to blade tip, with a generating potential of 2–3.5 MW.

Technological advancement, planning and ‘acceptability’ thresholds are key factors influencing the size of turbines as part of commercial developments, with, for example, 150 m being the United Kingdom threshold above which aviation lights are required on each turbine. Several consenting authorities have also undertaken or commissioned so-called ‘wind farm capacity studies’ trying to ascertain what size of turbine and size of wind farm can be accommodated without substantial landscape character change. These studies are informative with respect to ‘fitting’ development into the landscape but do not proactively plan for, or design and manage landscape change. Planning for, and accommodating more wholesome landscape change through developing wind farms, requires development of design strategies and policies which are expressly supportive of this type of development, and which actively embrace technology and size and scale advancement. However, most landscapes in the United Kingdom are subject to conservation strategies aimed at maintaining or restoring existing landscape character. Some would therefore consider that what could be described as a lag in technology in the United Kingdom is due to public objection to large structures in UK landscapes, and the reluctance of consenting authorities to support them.

Different foundation technologies have been used offshore enabling increasingly larger turbines to be used offshore. Phase 1 of Thorntonbank Wind Farm off the Belgian coast was constructed in 2012 using concrete gravity foundations, with 5 MW machines that are 157 m to the hub with 126 m rotor diameters giving 220 m tip heights. Later phases used steel jacket foundations and REPower 6.15 MW machines, the largest available in 2013, with rotor diameters of 152 m [6].

On land, the limitation to turbine size was initially the length of blade, with 46.5 m blades being the longest transportable on British roads, particularly on winding lanes through small villages, giving a maximum rotor diameter of 93 m. Split blade technology has dramatically changed this, with 60 m and longer blades now being available and deliverable (see Fig. 23.8). As with most types of development, a key factor influencing turbine design and overall development size of wind farm proposals, is economic and technical viability and optimization.

Some professionals are of the view that the landscapes of the United Kingdom are smaller in scale than landscapes elsewhere in Europe or the world, and that as a result, the UK landscape is less capable of absorbing large turbines. This does not necessarily mean that the scale of the landscape features is smaller, but that the extent of each landscape type is small, and variation across the country is diverse. This is the case in some places but certainly not across the United Kingdom as a whole. Different scale landscapes exist across the United Kingdom from the more densely populated parts of England to the less densely populated landscapes in the north and more rural parts of Wales and Scotland.

Similar differences in landscapes exist in France, Spain, Germany, the Netherlands, and Denmark. There are no European countries with landscapes similar to the vast plains of the United States or China, that can accommodate hundreds of turbines extending for miles. This leads to the question of whether these European landscapes can only accommodate smaller technologies? The answer to this question depends to some extent on the level of fit required. Whilst when purely considering landscape scale and size an argument can be had in favor of relatively small turbines, in practice the economics of wind energy developments in the United Kingdom and the availability of commercially viable turbines pushes developments toward larger size machines. This is further driven by the fact that the windiest locations have mostly been developed, and new developments may require taller turbines with larger rotor diameters in order to be economically viable on lower wind yield sites.

Both of these trends, development on lower wind speed sites and the availability of turbines, drive developers toward increasing turbine size.

23.5 The Perception of Wind Farms

There are three primary components of a wind farm that influence the perception of the development by people in the wider area around the wind farm.

Firstly, the height and size of the turbines as objects are important factors. Introducing objects of the height and size currently commonly proposed for commercial-scale wind energy development into any landscape represents a unique form of development which most people are not familiar with.

Secondly, the placement or composition of the individual turbines that collectively form the wind farm in different geometric formations (straight or curved line, square or triangular grid, loose group, etc.) greatly influences the perception of the wind farm with turbines in lines, grids, or groups creating strikingly different images.

The third unique aspect of wind energy development is the rotation of the blades, which introduces movement into the view, whilst most landscapes are generally ‘still’ above ground level. The relevance of movement is particularly evident when viewing two bladed turbines. When the lower blade passes the tower, either in front or behind, this appears to interrupt the flow of rotation, which some people may experience as an on/off effect (see Fig. 23.9).

23.5.1 Height and Size

People are accustomed to proposals for new developments into their local landscape and in general most proposed developments are designed to limit landscape change and to provide as good as possible a fit to the host environment. For example, housing developments in rural areas tend to follow the vernacular design and be of a size and scale similar to existing buildings. Likewise development of a city block in the center of New York may lead to the design of a skyscraper.

Early onshore wind energy developments comprised turbines of 35–55 m tall and at this height there is still a clear visual relationship between the turbine and other objects in the landscape such as trees that may be in the order of 20–30 m tall. Arguably at this height, turbines fit into the landscape. With the increase in absolute height this ‘connection’ between the turbine and existing landscape features is broken: a 125 m turbine does not relate to the vertical dimension of common landscape features we humans are familiar with. Arguably this disparity increases with turbines of 150–198 m, but in fact many people are incapable of readily estimating the actual height of turbines in excess of 100 m, because we are not used to these dimensions. This introduces a further factor that may influence people’s response, namely the ‘sense of scale’ and a desire to relate the height of an object to something we know. Some people also feel overawed when they know that turbines of a wind farm are taller than, for example, the telecommunications tower in London, or the Eiffel Tower in Paris.

Objections to wind farms often include references to the height of the proposed turbines relative to other known features in order to illustrate at these turbines are out of scale and therefore out of place. However, the actual ability to estimate the height of an object in the landscape depends on the availability of scale objects and importantly on perspective. This is illustrated in Fig. 23.10.

Furthermore in our experience, rather than absolute height, the predisposition of the observer to seeing wind turbines in the landscape is also an important factor in how he or she will perceive height.

23.5.2 Composition

Wind farms comprise more than one turbine. In the United States and China there are some wind farms of several hundred turbines, but in Western Europe most wind farms comprise between 10 and 50 turbines. The placement of a number of towers in a group formation or in a grid or in a straight, curving, or random line leads to a composition of objects which can be observed by people from different angles (see Fig. 23.11). Geometric layouts create very formal compositions and effects of stacking and perspectives are predictable. Group or irregular layouts have less predictable compositional effects.

Turbines must be separated from each other for safety and to avoid turbulence that reduces yield and causes additional wear and tear. This means that the turbines making up a wind farm must be spaced out, with distance increasing with increasing rotor diameter. Typically turbines are spaced a minimum of 6 times rotor diameter (some developers require 7 rotor diameters) from each other in the prevailing wind direction and 4 or 5 times across the wind. This represents a unique design challenge: four turbines with 100 m rotor diameters would be at least 600 m (5 full length football pitches) by 500 m apart. Whilst the actual footprint of a turbine is quite small, the ‘land take’ per typical commercial sized turbine (90–110 m rotor diameter) is therefore in the order of 30 hectares! This is illustrated in Fig. 23.12.

23.5.3 Movement

The movement of the blades, especially when seen from greater distances, may be the primary factor for a wind turbine being noticed in the landscape. It is an instinctive defensive reaction to look at moving objects in our peripheral vision. There are different aspects to this movement: the movement of the blades themselves; the rotation of the turbine to follow the direction of the wind; and the extent of the turbine that is visible to the observer. The diagrams in Fig. 23.13 illustrate:

• a turbine which is visible in full;

• a turbine where the tower is largely hidden but the hub or nacelle is visible and therefore one or two of the blades are fully visible at any one time;

• a turbine that is largely hidden, with only part of a blade visible.

In the second scenario, people will perceive a full turbine even if they do not ‘see’ the full object because the brain completes the picture. In the latter scenario we do not ‘see’ the whole wind turbine and the movement of the blade can be disconcerting if it is perceived as a windscreen wiper effect (see Fig. 23.14).

23.6 Landscapes With Power Generation Objects

As we said in the introduction of this chapter some landscape change causes strong feelings, particularly when change is man-made, and none so more than for power generation. Coal mining, quarrying, oil refineries, power stations, hydroelectric dams, wind farms, fracking, and solar panels on agricultural land are amongst the types of development that trigger strong responses. Some of those responses are influenced by the predisposition of the observer to the type of development proposed: people who are predisposed to supporting nuclear power and are of the view that wind farms are a waste of time may have strong negative responses to seeing wind turbines in the landscape, yet be more accepting of views of a nuclear power station. Opponents to nuclear power will not just ‘see’ the building housing the nuclear reactor but will also view this object as a facility they disagree with or are frightened of.

Current Scottish guidance on siting and designing wind farms points out that “People’s responses to wind farms vary—to some a wind farm may seem to dominate its surroundings, while others may view it as an exciting, modern addition with symbolic associations with clean energy and sustainability” [7]. Opinions on wind energy have evoked strong reactions: “Any windmill will wreck the scenery, it’s what the Scots deserve if they want their countryside wrecked” (Sir Bernard Ingham, former press officer for Margaret Thatcher [8]), though the younger generation are more imaginative: “I can see a wind farm from my house, I think they look like angels” (Jessica Dalgleish, age 9 [9]). Jessica has since had one of those “angels” named after her. Elsewhere, turbine have been given names: “Gigha Wind Farm was the first community-owned project to be connected to the National Grid, and the turbines are locally known as the Three Dancing Ladies—Faith, Hope and Charity” [10] (see Fig. 23.15).

It is important to be aware of these personal views and opinions with respect to seeing wind farms in the landscape. It is one of the most visible forms of renewable energy generation, as wind turbines are large, moving structures that have been put in prominent places seen by many people, while other renewable energy technologies such as biomass plants, hydro schemes, and wave or tidal schemes are less visible and more infrequent. Wind farms can be seen from long distances, and are becoming sufficiently numerous that they are unavoidably noticeable in some parts of the world.

With the increase of the number of wind energy developments in our landscapes, people’s views, especially of those opposed to this type of development, are increasingly vocal and planning decisions relating to wind power developments are increasingly adversarial. It is therefore important that landscape and visual impact assessments, which are undertaken as part of wind farm planning applications, remain professionally objective and neutral, and remain free from any potential personal opinion of the assessor. These assessments need to present an objective, well-reasoned and logical evaluation of the effects of the proposed wind farm in a particular landscape, and of the effects of the proposal on existing views and visual amenity.

If the proposal is granted consent, the introduction of wind turbines in any landscape will contribute to change in the character of the landscape. As said previously to some people this change is acceptable while others see wind farms as blight on the landscape. Assessments must recognize that opinions are varied and strong, and must present the facts and judgements in an unbiased way.

23.7 What Are the Effects of wind Farms on our Landscape?

Wind farms have a range of potential effects on our landscape, including direct effects on the site on which the turbines are built, effects on character and effects on views and visual amenity. It is common practice to evaluate the likely effect of wind energy proposals on our landscape by considering effects on views and visual amenity distinct from effects on the landscape fabric and its character. These latter effects are called landscape effects.

23.7.1 Landscape Effects

Wind turbines alter the landscape by introducing large moving structures above ground level, as well as tracks and other infrastructure elements at ground level. Direct effects include the loss of existing land uses, such as arable or grazing land, forestry, etc. as a direct consequence of the construction of tracks, substation, and works compound turbine foundations and other physical components of the wind farm (see Figs. 23.16 and 23.17). The power from each turbine needs to be cabled to an on-site substation from where it is exported to the electricity transmission network, ground disturbance also occurs along buried grid connection routes. Track and cable route construction may involve the removal of features such as hedge or wall sections, and substations may need new screening planting. Wind farms on forested land commonly require complete or partial felling of plantations.

These changes directly affect features in the landscape at a local level, but can also affect landscape pattern. Landscapes with a simple pattern of rectilinear fields or open un-enclosed moorland can be greatly affected by meandering tracks that do not respond to field boundaries or other existing features. Other more complex landscapes may be able to accommodate the development better, but may also become overwhelmed by it.

While the ground level land take is small, and land uses can largely continue below the turbines (with the exception of forestry), the perception of the character of the landscape changes. An open, undisturbed moorland area would be altered to a wind energy generating site with areas of moorland between the tracks and turbines. The introduction of an industrial layer to the landscape is a greater change in some environments than in others. Lowland, settled landscapes where man-made features are more common, can potentially accommodate wind turbines with less perceived change to the character of the landscape compared with remote undisturbed landscapes. However, settled landscapes have more potential objectors living locally, and while remote landscapes often have better wind resources, they are also often more environmentally sensitive.

Commercial forest plantations are man-made land use areas, and are not as sensitive to development as open areas. However, forest trees causes turbulence above the canopy, which we understand adversely affects performance of the turbines. Because of this manufacturers recommend that there should be a significant clearance between the lowest point of the swept circle and the tops of the trees (see Fig. 23.18). This means that full grown forest trees are too tall to be allowed to grow below the turbines in most circumstances, and trees must be felled and the land left bare, or replanted trees must be felled early, before they grow too high. An alternative is to increase tower heights to lift the rotors out of the affected zone, and to allow turbines to be constructed in small clearings called ‘key holes’ in retained forest plantations.

An important consideration when assessing effects on landscape is a perception of its character, and how the character of the landscape is affected or changed by introducing wind farms or turbines.

That turbines should ‘fit’ in the landscape has long been a recommendation with a view to minimizing landscape change. While turbines are in a similar height range to trees and buildings, it is possible to say that these can ‘fit’ in the landscape as features of similar scale to those existing. Turbines over 50–80 m to tip, however, can no longer be seen as fitting with other more human-scale elements. This is becoming more of an issue with turbines taller than 125 m and certainly with turbines up to 200 m. In many places turbines of this size will be perceived to be ‘out of character’ partly because we are unfamiliar with the size and height of these structures.

This poses unique challenges for the design of wind farms. It requires a different approach, recognizing that people find it hard to gauge the size of objects and may be overawed when they know the physical dimensions. Designing with structures of a height and size very much larger than trees or buildings requires an approach that recognizes that they should be designed to be viewed from afar as well as from nearby.

23.8 Mitigation

It is not possible to avoid all adverse effects on landscape and visual amenity resulting from wind energy proposals, and all onshore and offshore wind energy developments visible from the land will have a number of adverse effects. In general wind farms are designed to try and minimize the extent and number of significant effects whilst optimizing the generation capacity.

The design of a wind farm is critical to the appearance of the wind farm and its relationship with the landscape it is in. Wind farms should be designed with heed to the overall appearance of the development and how it relates to the existing pattern of the landscape. Structures can be placed in a landscape in ways that either detract or enhance the landscape: referring again to the cooling towers of Didcot Power Station, Berkshire: “The cooling towers were re-composed from the purely functional into the picturesque so agreeably that horror at their presence is mitigated by an appreciation of their grandeur – gigantic follies composed like gods in converse” [4].

In large flat open and geometric landscapes, such as, for example, the Fens in England or the polders in the Netherlands, formal geometric compositions of turbines in lines or grid formation may be most appropriate in terms of ‘built-in’ mitigation (see Fig. 23.19). In a gently rolling uplands, a loose grouping may be more appropriate (see Fig. 23.20), whilst in a landscape comprising of ridges, it may be appropriate to follow the ridge lines.

It may be appropriate when designing a wind farm to ask the question as to what extent the proposed wind farm will induce landscape change, and whether this change will mean that the landscape crosses a threshold, perhaps from a ‘landscape with wind farms’ to a ‘wind farm landscape.’ If this is the case the designer needs to decide whether or not the development should be contained to avoid crossing that threshold, or whether it could be enlarged in order to maximize energy yield, given that the landscape change is inevitable.

23.9 Conclusion

The landscape around us is a valued resource and changes to it evoke passionate responses. The only constant in a landscape is that it will change. Change is happening through natural processes, human processes, and as a result of our measures to combat climate change. Wind farms are renewable energy technologies that are changing our landscapes, affecting both views and the perceived character of the areas into which they are introduced. The number, size, and composition of turbines in wind farms are the key factors that influence the appearance of a wind farm in the landscape, and how it relates to its surroundings. The design of wind farms must take into account the nature of the receiving landscape and the potential effects that a proposal may have on the local area, as well as the technological requirements of the development as a power generating facility.