Notes Topic 15 - 1 INTRODUCTION 2 WIND RESOURCES 3 WIND...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 1 INTRODUCTION 2 WIND RESOURCES 3 WIND TURBINE COMPONENTS AND CONCEPTS 4 WIND TURBINE AERODYNAMICS 5 WIND TURBINE BLADE DESIGN AND BLADE MANUFACTURE 6 WIND TURBINE MECHANICAL DESIGN 7 GENERATORS 8 GRID CONNECTION AND POWER CONDITIONING 9 OPERATION CONTROL OF WIND TURBINES 10 CONTROL FOR SAFETY 11 INSTALLING SMALL TURBINES 12 WIND FARM DESIGN 13 DESIGNING THE WIND FARM LAYOUT 1 Introduction.................................................................................................................................................. 1 2 Wind Resources ........................................................................................................................................... 1 3 Wind Turbine Components and Concepts ................................................................................................... 1 4 Wind Turbine Aerodynamics....................................................................................................................... 1 5 Wind Turbine Blade Design and Blade Manufacture .................................................................................. 1 6 Wind Turbine Mechanical Design ............................................................................................................... 1 7 Generators .................................................................................................................................................... 1 8 Grid Connection and Power Conditioning................................................................................................... 1 9 Operation Control of Wind Turbines ........................................................................................................... 1 10 Control for Safety ..................................................................................................................................... 1 11 Installing Small Turbines.......................................................................................................................... 1 12 Wind Farm Design.................................................................................................................................... 1 13 Designing the Wind Farm Layout ............................................................................................................ 1 14 WIND FARMS AND COMMUNITIES .................................................................................................. 3 14.1 Approvals and Environmental issues .................................................................................................... 3 14.1.1 Statutory Approvals in Australia .................................................................................................... 3 14.1.1.1 Development Application ........................................................................................................ 5 14.1.1.2 Environmental Approvals ........................................................................................................ 9 14.1.1.3 Land Approvals and Agreements........................................................................................... 11 14.1.2 Issues Affecting the Natural Environment ................................................................................... 12 14.1.2.1 Flora ....................................................................................................................................... 13 14.1.2.2 Birds and Bats ........................................................................................................................ 17 14.1.2.3 Ground or Terrestrial based fauna ......................................................................................... 19 14.1.2.4 Effects on Land and Water Supplies...................................................................................... 21 14.2 Dealing with community issues .......................................................................................................... 23 14.2.1 The Clash of Wind Farms and Communities ............................................................................... 23 14.2.2 The Main Issues and the means to address them.......................................................................... 25 14.2.2.1 Visual Amenity ...................................................................................................................... 25 14.2.2.2 Wind Farm Noise ................................................................................................................... 33 14.2.2.3 Electromagnetic Interference ................................................................................................. 40 14.2.2.4 Shadow Flicker ...................................................................................................................... 41 Figure 14-2 Public displays held in Albany as part of the project’s Development Application to the City of Albany Council. ........................................................................................................................................... 7 Figure 14-3 Tourist area built by Western Power for the Albany Wind Farm, as a requirement of the Development Approval of the project.......................................................................................................... 8 Figure 14-4 Tourist road upgrade for the Albany wind farm, undertaken as a requirement of the Development approval for that project............................................................................................................................... 8 Figure 14-5 The 5MW Crookwell Wind Farm, near Goulburn, NSW............................................................. 10 Figure 14-6 Vegetation survey work being undertaken on a wind farm project in Western Australia, Western Australia. .................................................................................................................................................... 13 Figure 14-7 An example of rehabilitation work carried around the turbines for the Albany wind farm, Western Australia....................................................................................................................................... 15 Figure 14-8 Environmental guideline document issued to site workers at the Albany Wind Farm................. 16 Figure 14-9 Cows grazing adjacent to the Windy Hill Wind Farm at Ravenshoe, Qld. .................................. 20 Figure 14-10 Livestock exist in harmony with the Codrington Wind Farm, in Victoria. ................................ 20 Figure 14-11 Festival of the wind held every two years in Esperance, Western Australia, to in part celebrate that communities use of wind energy. ....................................................................................................... 24 Figure 14-12 Public display held at the Esperance shopping centre for the then proposed Nine Mile Beach wind farm. .................................................................................................................................................. 26 Figure 14-13 Computer generated image of the road design for the Albany wind farm viewed from an identified key viewshed. The road was designed to minimise its visibility from this and other points. .. 28 Figure 14-14 Example of a wind farm design which matches an ordered, straight landscape, here following a dyke on the Ijselmeer, The Netherlands..................................................................................................... 28 Figure 14-15 Example of a wind farm design in a random landscape, here at the Windy Hill Wind Farm, Ravenshoe, Queensland. Note also the use of green graduated towers to match the green pastures. ...... 29 Figure 14-16 Example Seen Area Diagram (ZVI) shown for the Albany wind farm. Colours are the number of wind turbine nacelles visible from that location.................................................................................... 31 Figure 14-17 Example of a wind farm photomontage undertaken for the Albany wind farm, shown together with the actual as built image..................................................................................................................... 32 Figure 14-18 Sound pressure levels for everyday things.................................................................................. 35 Figure 14-19 Background noise levels being measured for a wind farm. ........................................................ 38 Figure 14-20 Measured background noise levels and estimates of noise with wind farm operating for the Albany wind farm. ..................................................................................................................................... 38 Figure 14-21 Example estimations of wind farm noise output for the Nine Mile Beach wind farm, Esperance.39 Figure 14-22 General map of the Esperance area showing previous and proposed wind farm installations relative to the town..................................................................................................................................... 42 Figure 14-23 A before and after shot from the Wireless Hill lookout towards the town’s wind farms, including a photomontage of the proposed Nine Mile beach wind farm facility....................................... 43 Table 14-1 Examples of the types of approvals required in Australia for wind farm developments. What approvals are required will depend on which state the development is in, how large the development is and who is building it. Those shown in bold are generally considered mandatory. ................................... 4 Table 14-2 Estimated bird mortality per year due to collisions with various artificial structures in the United States. Taken from Reference1.................................................................................................................. 17 Table 14-3 Issues considered when assessing the visual amenity of a proposed wind farm site. .................... 27 Table 14-4 General visual amenity principles used when designing a wind farm. .......................................... 30 Exercise 14-1 Wind farm natural environmental issues – flora and project approvals. ................................... 21 Exercise 14-2 Wind farm natural environmental issues – bat strikes during operation. .................................. 22 Figure 14-1 Documents submitted to the City of Albany as part of the Development Application for that project........................................................................................................................................................... 6 14-1 14-2 14 WIND FARMS AND COMMUNITIES 14.1 Approvals and Environmental issues There is enough wind blowing across Australia every year to easily provide the nation’s complete electricity needs. A quick calculation reveals that approximately one hundred thousand 1MW wind turbines would be needed to accomplish this and in principal this is achievable – after all, this is orders of magnitude less than the number of cars on Australia’s roads. However, apart from significant cost, transmission and technical stumbling blocks there remains social issues that also challenge such wide spread wind energy use in Australia. These are community attitudes and environmental effects. The role of the wind farm designer to establish what is known as an appropriate wind farm, has been discussed previously and this involves including social and environmental issues in the wind farm design. Engineers are typically uncomfortable when it comes to the former of these and sometimes treat the latter with indifference, but communities can be very strongly against wind farms and, as such, the success or otherwise of the project can depend heavily on the wind farm design. Fitting and moulding that to the social and environmental constraints that exist is challenging work. This topic looks at approvals and environmental issues to do with wind farms. It is important for the wind farm designer to have at least a limited understanding of the processes under which a wind farm is allowed to be built, that is, the approvals it requires. This is because such approvals can be heavily influenced by public opinion and the effort put in by the developer to satisfy and meet the resulting issues, through the project’s design, is important. The approval path also largely sets the timing and necessary environmental studies for projects that in turn can affect the project’s economics. it very cumbersome to obtain approvals for wind energy projects, even more so than for fossil fuel power plants (Reference: 2). Wind farms in Australia sit within a similar framework and it can be very costly and lengthy to get approvals, although some states in Australia are now coordinating the approach to wind farm projects to help developers get through the processes involved, see Reference 3. The type and depth of approvals required also depend heavily on the type of wind farm. A single small wind turbine development won’t require visitations or presentations to Federal ministers although a large wind farm may. Even a small wind turbine installation though will require some level of approval (see Topic 11). In granting approval the particular body will either issue a permit to proceed or provide a formal letter issuing the same. Usually one approval precedes another so that responsibility shifts from one agency to the next in a chain although the processes involved can usually run in parallel. Planning legislation in each state dictates who has final approval on such a development but often approval of a Development Application to the local Council is the main requirement. This can be daunting for a small Council and in cases of large wind farm projects they may request that the assessment be undertaken at a higher State level by the Planning Minister. For a large wind farm in Australia, examples of the types of approvals possibly required are given in Table 14-1. This is not a complete list although indicates the spread possible. Table 14-1 Examples of the types of approvals required in Australia for wind farm developments. What approvals are required will depend on which state the development is in, how large the development is and who is building it. Those shown in bold are generally considered mandatory. Environmental issues exist with any development but there are a few in particular which arise in relation to wind turbines and their effect on the natural environment and these are introduced here. Later in the topic, environmental issues affecting the social environment will also be discussed. Organisation 14.1.1 Statutory Approvals in Australia Federal Government Once the initial site selection has taken place for a wind farm project there begins a feasibility process that involves examining details surrounding that site. Often this merges with the initial site selection work in what is known as a pre-feasibility study and, if successful, becomes ultimately a detailed assessment study. Reference 1 provides a good breakdown of how such studies occur in Australia. At some point in time in these processes it will be necessary to investigate and begin dialogue with certain bodies that will be required to grant approval for the project before it will be allowed to proceed. Without such approvals the developer face either fines or the risk of imprisonment if that project proceeds regardless. Such discussions begin when wind prospecting or monitoring is undertaken, as approval will be needed to install the mast and possibly gain access to the land. This is usually assessed by the local planning authority (the local Council), which may request advice from other groups such as civil aviation safety groups or the RAAF before granting approval. Obviously such a process is a public one and hence the developer’s interest in an area will have to be explained and this triggers a range of social issues that will be discussed later in this topic. Approvals for wind farm developments in Australia can presently involve every level of government, especially for large wind farms. Such a situation exists in many countries and in the United States can make 14-3 State Government Local Government (Councils) Approval type Environment Tariff concessions Heritage Land Import Customs RAAF Civil Aviation Environment Land Native title Planning & heritage Road use Land clearing Purchase of electricity Connection to network Generation Development Signage/advertisement Community events Transportation Comments Federal approvals usually require a certain trigger. For example, the Environment Protection and Biodiversity Conservation Act 1999 is triggered if certain types of environment or species are affected. Import and customs approvals are for imported product only. The majority of approval work is at this level and differs enormously between states in Australia. Approvals regarding the purchase of electricity can be for power purchase agreements with a State owned utility. Road use is for transportation of heavy equipment. Connection to the network is usually with the state or through the Network Service Provider (see below in Private). Development approval is nearly always required unless special status exists for the developer (such as Crown immunity or the project undertaken using special State project facilitation). Continued over page 14-4 Private Land access Recreational users Native Title Connection to network Purchase of electricity Noise and building buffers Approvals from private organisations can involve contractual negotiations, such as for land access and use. Sometimes, recreational users consent is required before Council approval is given. If approval were not received for any of those approval types shown in bold in Table 14-1, it would be considered fatal for a wind farm development and could stop the project from being developed through some legal mechanism. Herein lies a difficult issue in terms of government approvals for the wind farm developer - every level of government has its own political issues and agendas and these have to be understood and dealt with accordingly. Nowhere is this issue of politics more problematic than at the Local Government level since a decision will be made by Councillors who are dependent on their constituent neighbours for re-election. These are the same neighbours that may be very nervous about a planned local wind farm. Typically, Councillors have little or no experience with wind farms and are far removed from the broader and global environmental and energy use issues which drive wind energy use. Local issues will dominate such a debate and, if approved, usually come with added conditions, for example a tourist area is needed in the design, or turbines are required to be coloured to align with local town planning rules, or the transmission line is required to be underground. At higher government levels approvals can take on a very different flavour. Australia’s policy of importation and local content, greenhouse gas policies, Australia’s bio-diversity treaties, energy use diversification, potential intellectual property exports and even tariff restrictions between countries are some of the heady issues which can be raised during the wind farm approval processes. These can all affect the wind farm design as a certain turbine type or size may be more appropriate, or siting in a particular way preferred. At some levels the general public and the developer has the right to appeal an approval/disapproval and this is a necessary safeguard in the process. Reference 4 is the results from such an appeal in the Victorian Civil and Administrative Appeals court for the 22MW Toora wind farm in Victoria being developed by Stanwell Corporation of Qld. This appeal was undertaken by wind farm opponents against the local Council granting Development Approval involving a construction permit for the development to proceed. Such avenues are commonly used in Australian courts by opponents and, in this case, delayed the development but did not prevent it. (1) To ensure some type of engineering scrutiny of the project, (2) To make sure the project aligns with the plans for the area (planning guidelines, policies or Town Planning Schemes) and is therefore a suitable use of the land in question, and (3) To ensure that the community who must live with the project are informed about it have some kind of input. Nearly all wind farms in Australia will require a Development Application to be lodged by the developer. One may not be needed if the wind farm is so large that it is of State or even National importance – for example because of the need for the electricity, the jobs it represents or manufacturing possibilities – and then a higher authority can be called in, such as a State Planning Office, to undertake development approval. The Federal Government also offers Major Project Facilitation status for such large projects, which may lead to a similar result. A Development Application can be as simple as one page outlining the project, the developers name and some indications of where the project is intended and what for. Alternatively, it could be a large document including detailed plans, environmental study results and much more. It is normally presented to the Council’s planning department who in turn analyse what it contains before presenting this with a recommendation to a sitting of the Council for a vote of approval. At some stage in this process, public comment is sought and the results included into the material presented to the Councillors for their consideration. A useful example of this process is the Albany wind farm in Western Australia. This project was presented to the Albany City Council in the form of a Development Application that included the standard two-page application plus a special attachment (Reference: 5) that discussed the project and its community relations, a separate Environmental Assessment document that presented environmental findings(Reference: 6), and a further document that presented the Environmental Management Plan for the development (Reference: 7). The front covers of these documents are shown in Figure 14-1. All these documents were made publicly available and the proponents, Western Power, held a 7-day public display as requested by the Council, see Figure 14-2. Figure 14-1 Documents submitted to the City of Albany as part of the Development Application for that project. It is impossible within the time constraints of this course to describe the processes involved with gaining approvals for all wind farm projects; nor is it practical, as while every wind farm will have similar issues, the ways these are dealt with by local or State authorities differ. Nevertheless, it is worthwhile outlining three primary approvals in some detail. 14.1.1.1 Development Application Under State law in Australia proponents of developments of a certain type and size have to make an application to the local authority, the Council, for approval to proceed. This is known as the Development Application and its purpose is three fold: 14-5 (Source: Courtesy of Western Power) 14-6 Figure 14-2 Public displays held in Albany as part of the project’s Development Application to the City of Albany Council. Figure 14-3 Tourist area built by Western Power for the Albany Wind Farm, as a requirement of the Development Approval of the project. (Source: Photo courtesy of Western Power) Figure 14-4 Tourist road upgrade for the Albany wind farm, undertaken as a requirement of the Development approval for that project. (Source: Courtesy of Western Power) In the case of the Albany wind farm, the project was approved by the Council subject to a number of conditions such as the construction and operation of the wind farm complying with the project’s Environmental Management Plan and the upgrading of the closest public road to facilitate tourist access. Western Power had the right to appeal these conditions but thought them reasonable so accepted these. Figure 14–3 shows the resulting tourist area and Figure 14–4 the upgrade to the tourist road, both undertaken as requirements of the Development Approval from the Albany City Council. 14-7 (Source: Courtesy of Western Power) When assessing a Development Application the Council must scrutinise a wind farm from many (often conflicting) perspectives, including the local Town Planning Scheme which provides rules accepted by the wider community for developments and how such a development will affect the area. This may preclude certain types of developments is some areas – for example, industrial developments in housing estates - and dictate even what colours project components can be. Council engineers also assess the likely impact on 14-8 services such as roads, and in this case would request comment from the local Main Roads department to aid their assessment. issues. This document must be made publicly available with comments sent back to the approval authority for consideration. An example of such a document is the Statement of Environmental Effects (Reference: 9) undertaken for the 5MW Crookwell wind farm in NSW, with this wind farm shown in Figure 14-5. Often it is a requirement to lodge certain engineering drawings with Councils so that they can be audited to ascertain that appropriate standards are met and that the structures are safe. While wind turbine design is outside of the expertise of most Council engineers, often they will seek proof that turbine footings, structures and roads are designed appropriately and safely. An example of this would be a tourist parking area or road that must be designed to have adequate room and facilities for the types of tourist vehicles and numbers expected. Some wind farms see over 100,000 tourist cars a year (or more than one car every 5 minutes) and roads and facilities have to be appropriate for such load. Another example is that the turbine structures are designed to comply with appropriate Australia construction standards for wind loading. Figure 14-5 The 5MW Crookwell Wind Farm, near Goulburn, NSW. Development Applications sometimes have what is known as third party appeal rights. This means that an individual, not happy with a Development Application approval given by a Council, can appeal the decision in a court of law, which in Western Australia is known as the Town Planning Appeals Tribunal. The example of the Toora Wind Farm discussed earlier in Victoria shows such an appeal process in action in that state. Such appeals to wind farm projects can provide a significant delay and introduce unwanted uncertainty in the process. However, they offer an important safeguard to prevent inappropriate wind farm developments and a developer which has carried out appropriate work in the design of the wind farm should have little to fear and should be able to adequately defend the project. (Source: Photo courtesy of Pacific Power) 14.1.1.2 Environmental Approvals It is impossible to develop a wind farm of any size in Australia without regard to its environmental consequences. Environmental approvals provide a framework and an arbitrator under which such issues can be identified and scrutinised. Such approvals also provide the means for public debate and identify the authority to apply penalties if breaches or non-compliances occur. Environmental legislation in Australia varies from State to State and it is important that the wind farm designer understands those issues of key importance to the authority in question. For a large wind farm State legislation usually requires a document, sometimes called a referral to be lodged with the relevant environmental protection agency. The referral describes the proposed wind farm, its location, the types of environmental issues identified and how these issues are proposed to be managed. An example of a referral document made in Western Australia is given for the Ten Mile Lagoon wind farm at Esperance in (Reference: 8). If environmental approval is granted a letter will be sent to the developer, usually with conditions. Such conditions could be that certain environmental safeguards need to be put in place, or that a number of environmental audits and reports need to be undertaken at various stages of the construction and operation of the facility. It is nearly always a requirement in Australia that the developer of a large wind farm also develop an environmental management plan. Such a plan sets out the environmental issues and how they will be managed, usually audited by the approval agency or delegate. In Australia the Federal Government has enacted legislation known as the Environmental Protection and Biodiversity Conservation Act 1999 (EPBC Act), which is aimed specifically at developments that may have an effect on: - World heritage listed properties Internationally important wetlands Nationally threatened flora and fauna Listed migratory species Commonwealth protected marine areas For a large wind farm, following submission of a referral to the environmental authority, a level of assessment will be set. This dictates what the developer must go through in terms of environmental studies, reporting and public scrutiny. As an example, the developer may have to produce a document such as an Environmental Impact Statement that covers a certain number of issues and the results of studies into these or involve matters of a nuclear nature. Under the legislation, a referral is required to Environment Australia, who manages the program, if one of these areas is affected (known as a trigger). This referral is then assessed with the result being approval to proceed with conditions or the matter may end up before the Commonwealth Minister for the Environment for special consideration. Ultimately the project may not receive environmental approval because of environmental impacts being considered too high. Examples of referrals made under this legislation are the Musselroe Wind Farm in Tasmania by Hydro Tasmania (Refernce: 10) and the Yabmana Wind Farm proposed by Wind Prospect Pty Ltd in South Australia (Refrence: 11). 14-9 14-10 For smaller wind farms sometimes it is possible for the local Council to undertake the environmental approval. Under these circumstances the conditions given in the Development Approval can include specific environmental safeguards that the Council inspector would police. An example of an issue considered worthy of referral under the EPBC Act involved the Woolnorth wind farm in North western Tasmania. During the environmental studies for this development it became apparent that a number of bird species might be at risk from installation of a wind farm, particularly the Orangebellied Parrot, which is a migratory species listed as critically endangered with only a few hundred individuals in existence. Through the referral process, Hydro Tasmania, the project’s proponent, committed to management strategies including the planting of certain plant species away from the wind farm to attract the birds away. As a matter of interest, the Orange-bellied parrot issue has also arisen in respect of a number of planned wind farms on the south coast of Victoria, an area to which this species flies during its migration. 14.1.1.3 Land Approvals and Agreements heritage and knowledge. Typically land that is affected is that which is not in private ownership, with a good example being Crown and certain types of Lease Hold Land. Where a Native Title issue exists a process of information and review is required with the appropriate Aboriginal elders or representatives. For the wind farms built in Esperance, Western Australia, for example, negotiations were undertaken through a legal representative and involved several visitations to the proposed wind farm sites and meetings. This was to ensure that no areas of cultural or spiritual significance were affected (such Ethnographic and Archaeological studies are discussed more later in this topic) and that Aboriginal people were comfortable with and approved of the developments. 14.1.2 Issues Affecting the Natural Environment Wind turbines affect the natural environment in which they operate and these effects need to be identified, understood and managed. A wind farm needs land and its operation will affect not only the uses of the land directly under the turbines but sometimes that of surrounding areas. The developer of the wind farm must have some kind of legal land tenure on the area directly affected and, depending on the issues involved, those surrounding areas as well. If not, that development risks losing access and the ability to operate the wind turbines and hence the project will fail. To obtain land tenure requires negotiations with and the approvals of the legal owner or custodian of the land in question. These can be private individuals and companies or even the Crown. Such negotiations usually have to begin early on in the project and can be legally and commercially complex, costly and, most often, lengthy. Often negotiations are held through a third party body or group who have been given responsibility to act on behalf of the legal owner of the property in question. This could be a Real Estate Manager, a legal representative or even a local council who has been given a management order over a portion of Crown Land. Such representatives will be both professional and able to maximise the business value to that owner. Hence the wind farm developer needs to have some negotiating skills, or their own representative, to ensure they also receive a fair deal. Land agreements can vary from project to project but usually involve a lease or some kind of easement or even the purchase of the land in question for the project. An example of a lease arrangement is the 18MW Codrington wind farm in Victoria, owned and operated by Pacific Hydro, where the land for the turbines is leased from the farmer who owns it. With such leases it is usual practice for the owner to obtain either a lump sum per turbine per year or a portion of the electricity sales. In Australia such leases have seen values between $2000- $9000 per turbine per year negotiated and this depends on the relative value of the site in question. Obviously the final cost paid to landowners is treated as commercially confidential information. An example of an easement is the 30MW Mumbida wind farm in Western Australia, owned and operated by the Wind Energy Corporation (under construction in 2003). The land for this wind farm involves an easement – a legal clause in the land title that gives the wind farm owner the right to build and operate the facility – that was negotiated with the landowner and involved a single lump sum payment. While there are valid environmental reasons to use wind turbines to create the energy we use every day, all energy production has negative environmental impacts and wind energy is no exception. For wind turbines to become an integral part of our communities the negative consequences to the natural environment must be acknowledged and minimised. Ultimately, these negatives also have to be accepted. In relation to the natural environment, the effects from wind energy occur in a number of categories that can be broadly defined as; • • • • Flora (vegetation) Fauna (animals) Effects on land Effects on water supplies and water ways If a wind farm is sited and designed inappropriately it can be significantly harmful to the natural environment. Fortunately, in Australia the wind farms built so far have been found to be relatively environmentally benign as a consequence of good design and siting practices. Such a situation also exists in the majority of countries that use wind turbines on a significant scale. In studying a wind farm proposal it is not normal practice to include environmental issues associated with the manufacturing of the wind turbines and other equipment for the project. This rarely happens with any project in Australia and because of this such issues will not be pursued in this course. However, there are greenhouse gases emitted during manufacturing and transportation of wind turbines, and hydrocarbons and other volatiles are emitted during blade manufacturing so this is an issue the industry needs to address. Some wind turbine companies are now attempting to quantify such issues and an example is Vestas from Denmark which reports annually on the environmental consequences of its manufacturing work – including energy, raw materials, emissions and waste. Sometimes land negotiations involve Aboriginal groups who can have certain rights under Native Title legislation. A complex issue, such legislation varies from state to state but at its heart is recognition that indigenous Australians do have an important link to the land and need to be consulted in regard to their For the developer and designer of wind farms it is necessary to assess the direct issues involved and to act according to local findings. Always this creates a tension between financial and environmental issues and normally a compromise is required. How large a compromise is acceptable is difficult to judge – after all, we need the clean electricity but are we willing to accept a certain number of bird strikes per year? Ultimately answers to such questions will depend on the level of approvals and the arbitrator who is setting the environmental hurdles. 14-11 14-12 14.1.2.1 Flora Australia has unique flora (vegetation) found nowhere else on earth and this represents a significant amount of the natural value of this continent. The sheer number of flora species and diversity in Australia has seen it recognised as one of the great flora locations in the world. Such natural value is precious, and although the recent history of Australia has seen its flora treated largely with little respect, it is recognised now that it must be protected. Wind farm developers and designers need to appreciate this issue. Wind farms can affect flora through the following means: • • • • • Physical disturbance and removal of plants during the placement of the wind turbines, and the building of roads and electrical interconnection, The introduction/spreading of weeds and diseases to areas through construction traffic, The denuding of areas prone to wind and water erosion, An increase in the risk of fire, and An increase in human pressure in an area. Such disturbance is not limited only to native flora. Building a wind farm on cleared grazing or cropped farmland at first glance seems relatively benign. However, one inappropriate spark could lead to the loss of entire crop, livelihood and possibly someone’s life, and earth-moving equipment can easily spread plant diseases across farms. During the wind farm pre-feasibility and feasibility stages this issue is assessed through some type of flora survey. For small developments this could be as simple as a literature search and investigation of the site with the landowner or local Council environmental representative. For large-scale wind farms it can be as time-consuming as a metre-by-metre GPS grid site evaluation by a flora expert, see Figure 14-6 and the flora results in References 8 and 11. If this is involves native vegetation (termed remnant vegetation) these searches need to be exhaustive as the area could contain significant or endangered species. Figure 14-6 Vegetation survey work being undertaken on a wind farm project in Western Australia, Western Australia. Flora surveys need to be undertaken by someone skilled in the art, usually a botanist or local flora expert. Sometimes the studies need to cover the four seasons as an area with many species may make it difficult to identify them all unless they are flowering – spring is often a good time for such surveys but not all species flower at this time for example. On cleared land such studies should be straightforward and less time and cost intensive. Sometimes it is also necessary to obtain input to flora work from local Aboriginal people. Known as an Ethno-Botanical Survey such input can identify areas where species at first appear not to be present, but Aboriginal people’s long-term knowledge is that given time it will appear. After all, some species only propagate every ten years and can lay dormant in between. Flora surveys result in a mapping of the area into vegetation types with specific endangered, valuable or rare plants identified. Such mapping can be seen in the flora sections of Reference 8. The wind farm designer then has the job of micro-siting turbines and designing wind farm roads and electrical infrastructure away from these areas. Sometimes such a flora survey may indicate that the development is inappropriate. Flora surveys can be very important for the establishment of wind farm procedures. Often these are listed in the project’s Environmental Management Plan (see for example Reference 6) and can involve such issues as: • • • • General clearing guidelines - what method to use to remove vegetation, Weed and disease hygiene principles – for example, the washing down of plant machinery before going onto the wind farm site to neutralise diseases and remove seeds, Specific species principles – how to manage a species that is important but will be affected by the wind farm construction, Rehabilitation principles – seed collection from the local biomass, stockpiling of cleared vegetation for coverage of denuded areas to prevent erosion, the replanting of species in areas Figure 14-1 shows rehabilitation work surrounding a wind turbine base at the Albany wind farm in Western Australia. At the Albany wind farm, areas that were disturbed during construction and not needed for ongoing maintenance work went through a rehabilitation exercise aimed primarily at restoring the flora. This included the mulching and storing of vegetation before turbine erection, and the brushing of disturbed areas using this material following construction completion. The figure shows a large area eventually covered with such brushing. This rehabilitation also included the collection of seed from surrounding flora that was spread across the brushed areas to aid in recovery. (Source: Photo courtesy of Biota Environmental Sciences Pty. Ltd.) 14-13 14-14 Figure 14-8 Environmental guideline document issued to site workers at the Albany Wind Farm. Figure 14-7 An example of rehabilitation work carried around the turbines for the Albany wind farm, Western Australia. (Source: Photo courtesy of Western Power) Often contractors working on large wind farm projects have very little appreciation of flora value and it can be difficult to ensure that they respect the principles outlined in the project’s Environmental Management Plan in this regard. Reference 1 includes discussion about this in an Australian context. It is generally accepted that contractual penalties can be included in projects for unauthorised vegetation clearing by contractors, which provide added incentives for workers to do the right thing. Sometimes it is necessary to remind workers of their obligations and Figure 14-8 shows how this was done for the Albany wind farm. (Source: Courtesy of Western Power) 14-15 14-16 14.1.2.2 Birds and Bats magnitude less than communications towers – this suggests that this issue is more problematic for those other structures listed than for wind turbines. Wind turbines can kill birds and bats (termed avi-fauna) and the possibility of such can produce stiff and emotional opposition to wind farms. After all, most people dislike the unnecessary destruction of any animal. These incidences have been used by wind farm opponents to such an extent that many people, even those without any connection to wind farms, know about the issue in relation to wind turbines. Often this is one of the first issues raised by the general public in any wind farm development (see for example Reference: 12 & Reference: 13). Such a possibility can also cause a dilemma for environmental groups who support renewable energy but are concerned about effects on fauna. In Reference 1 it is stated that the number of birds killed by artificial structures in Australia is likely to be smaller than in Table 14-2. This is in part due to the different mix of species here than in the U.S. and with those appearing more at risk being less common. There is, however, the potential for collisions between birds and bats with wind turbines in Australia and while it appears that the mortality numbers will be low compared to other man made structures the issue has to be addressed by the developer and wind farm designer. The effect of wind turbines on avi-fauna became evident in the 1980s and was particularly controversial in the early 1990s because of concern over raptor collisions with wind turbines in the United States and the south of Spain at Terifa (Reference: 13 and Reference: 14). These events were publicised widely and the wind turbine community had to respond to this issue. A great deal of work has since gone into identifying how large the issue is and how to deal with it. Anecdotal evidence from operational wind turbines in Australia is that there has not been a significant impact on birds. There have been some unpublished accounts of avi-fauna being hit by turbines in Western Australia although the carcass sitings were rare – less than 1 per year. Until such time as the local bird populations in Australia that are susceptible to collisions with wind turbines are identified, it is prudent for the wind farm developer and designer to treat this issue with some caution. A particular problem occurred in relation to bird strikes at wind farms in the Altamont Pass in California. At this location up to 7000 wind turbines were installed, some in wind walls (described in Topic 12), which are very closely packed turbine alignments. All of these turbines were small and fast turning (approximately 100kW each) and the bird strike problem occurred mostly at the end of the rows, where it appears the birds were trying to fly around the densely packed turbines. Many of these turbines also used lattice type towers and some birds used these for nesting and perching to seek out prey, resulting in habitation very close to the turning rotors. In turn this lead to increased mortality due to the birds being swept into the rotor during gusts or from the birds attempting to fly at prey directly through the rotor. Collisions between avi-fauna and wind turbines are not the only effect of a wind farm on such animals, with the disturbance to habitat and habitat loss, and changes to migratory patterns, being related issues. This can occur during the wind farm construction where obviously increased machinery, noise and movements will pose a difference to the local and passing fauna but also, following the construction, the turbines will be operational and there will be increased human presence in the area. This will change the environment for birds and bats and such changes can put added pressure on species to move or change. In Reference:14 the number of birds killed at Altamont due to the wind turbines is described in a high year as being approximately 400, or a bird mortality index of 0.059 birds/turbine/year or 0.58 birds/MW/year. Hence a 20MW wind farm of similar design and location would be expected to result in, approximately, 12 bird deaths per year. This is considered high in the industry and more modern designs would be expected to have much lower numbers or zero. In Reference 1 this issue is described in an Australian context with reference to several studies undertaken in the United States. Table 14-2 is taken from this reference and shows upper and lower estimates for bird deaths due to collisions with a number of different sources - here the impact of wind energy can be seen to be significantly smaller than that of technologies such as vehicles and power lines. Lower Estimate 60 million 98 million 0.1 million 4 million 10,000 Fortunately, a number of design practices have emerged in the wind energy industry that have been found to reduce the impacts of wind farms on avi-fauna, being; • • Table 14-2 Estimated bird mortality per year due to collisions with various artificial structures in the United States. Taken from Reference 1. Source of Collision Mortality Vehicles Buildings and windows Powerlines Communications towers Wind farms It is normal practice to consult with a recognised avi-fauna expert when undertaking a wind farm development and obviously the amount of consultation, as with flora issues, will depend on the avifauna present, its status and the potential impacts. In (Reference: 15) it is stated that such studies can be detailed, prolonged and expensive. In Australia, such studies can take up to 12 months to complete, see Reference 1 and involve trapping programs, field surveys and desk-top literature reviews. An example of a study undertaken for Western Australian wind farms is given in detail References 7 & 8 while the referrals sited earlier in References 10 & 11 show work undertaken in Tasmania and South Australia respectively. • • • Upper Estimate 80 million 980 million 174 million 50 million 40,000 • Of course, there are far fewer wind turbines in the United States than there are vehicles and this accounts for some of the differences in Table 14-2. However, even if there were to be a hundred fold increase in the installed capacity of wind turbines in the U.S. the number of bird fatalities would still be an order of 14-17 • • • known bird migration corridors and areas of high bird conservation should be avoided, or suitable gaps in the wind farm design should be allowed for to aid migration flights, micro-habitats of rare or endangered avi-fauna species should be avoided by sensitive micro-siting of turbines, roads and electrical infrastructure, construction should be planned and timed outside of the breeding or migratory season, solid tubular towers should be preferred to lattice types to avoid perching, fewer, slower rotating larger turbines are preferred to numerous smaller units, and placement should be such that birds have clear spaces to fly through the wind farm, lights at night on the turbines (such as aircraft warning lights) should be avoided as these attract insects which can themselves attract birds and bats, wind turbine nacelles should preferably be smooth and rounded, or designed so that nesting is difficult, within the wind farm electrical power connection should be underground, and, wind turbine placement should avoid obvious bird pathways such as saddles and up against cliff-lines or ridges where birds tend to soar. 14-18 In some instances wind monitoring masts that have no guy wires are preferred, as these can also lead to bird deaths. Often where a particular bird species is likely to be affected, a program can be established by the wind farm developer to either attract the bird species away from the area by increasing its food or habitat at another place, or through a program of trapping and populating. While such programs can be expensive they can grant access to sites with very good wind resources – an example of such a program has been mentioned earlier involving the Woolnorth wind farm in Tasmania, where certain plant species were planted away from the wind farm to attract birds away. Figure 14-9 Cows grazing adjacent to the Windy Hill Wind Farm at Ravenshoe, Qld. 14.1.2.3 Ground or Terrestrial based fauna Like the effects on avi-fauna, the impact of wind turbines on land or terrestrial based fauna elicits a strong emotional response from the general public. Fortunately, the potential in this regard is small primarily as the operational part of the turbine is well away from where the animals live. Overall, ground based fauna have been found only to be slightly effected by wind farms, see Reference 13. The largest risk to terrestrial fauna from wind turbines and the construction of wind farms is through the following issues; • • • • • • • (Source: Photo courtesy of Stanwell Corporation) habitat loss or disturbance, introduction of feral animals introduction of diseases, disturbance to food and water resources, disturbance of breeding or migration, increased number of vehicle movements, and added human pressure in an area. Figure 14-10 Livestock exist in harmony with the Codrington Wind Farm, in Victoria. Some of these issues are discussed in Reference 1. Of the issues above, the first involving habitat disturbance is considered the largest effect and involves physical changes to an environment in which the fauna lives, passes through or forages. This can also involve transient disturbance such as heavy vehicle use during construction and general construction noise. This can be particularly disturbing to native animals that are often timid or shy although, generally, once that disturbance has ceased the animals return and are largely unaffected. The kangaroos grazing around the wind turbines at Esperance in Western Australia, to the delight of many tourists, are evidence of this. Where a wind farm is being considered for an area of natural vegetation a fauna study must be undertaken, by a recognised expert, commensurate with the size of development and the likely impact. While the area may not appear likely to hold many species, wind farm developers and designers are not experts – for example, frogs, lizards, snakes and even certain insects can inhabit the most unlikely locations and any one of these could be an endangered or threatened species. References 7, 9 & 11 all contain either fauna studies or summaries of such studies for individual wind farm projects from around Australia. Most of the wind farms built in Australia are on cleared farmland where the animals most at risk are domesticated. While there appears to be no evidence that wind turbines cause any negative effect on livestock (see Figure 14–9 and Figure 14–10), wind farm construction can spread disease and disturb the grazing animals and these issues must be factored in to the work program during this time, often through the project’s environmental management plan. 14-19 (Source: Photo courtesy of Pacific Hydro Limited) Even wind farms on cleared grazing land can affect native animals as areas close by can be remnant or natural land and may hold significant populations of native animals. Often these animals forage or move across the farmland and construction activities can disturb this. It is particularly important that areas remain untouched and avenues for fauna movement remain open so that these activities can continue. It is also important that feral animals are kept off-site, as the introduction of such can have devastating consequences on native animals. A wind farm will also bring much greater human pressure. This can be recreational, tourism or simply the maintenance team doing their day-to-day activities. Either way, this added pressure is a change to an area, 14-20 which must be managed to limit the effects on ground-based fauna. This could include limiting access of tourist to certain areas, the types of activities that are undertaken or even the hours of the day when the wind farm gates are left open. Such issues need to be identified early and included in the management of the wind farm during construction and once it becomes operational. 14.1.2.4 Effects on Land and Water Supplies Any construction activity changes the land it is on and this can lead to negative impacts on it. For wind farms, the most serious issue is wind erosion. In certain soil types that are lose on the surface or dry for long periods of time, the wind can easily remove the top material where the holding down foliage or any other mechanical barrier has been removed. This can lead to blowouts that are notoriously difficult to rehabilitate as the soil needed for stabilisation and the growth of plants has been removed. A related issue is water erosion that is a common problem on any construction site that requires roads and civil work. Many techniques exist to prevent both wind and water erosion, such as the use of mulching and brushing and the installation of drainage or artificial mechanical barriers that hold down the soil to prevent it moving. Such erosion can also lead to the pollution of waterways. An added risk in this regard is that large construction vehicles carry hydrocarbons that can easily leak or be spilled during re-fuelling and disappear into the soil only to be leached into the local watercourses with the next rains. No wind farm construction should ever result in the pollution of waterways, as it is a simple task to put in place mechanisms to prevent this e.g. emergency spillage containment procedures and proper civil engineering drainage. Sometimes wind turbines are located in areas with an underground water resource that can be at risk from liquid hydrocarbon releases or physical penetration during the driving of earthing rods or foundation infrastructure. If this is the case then the local water authority will probably become involved with the approval processes and advice can be obtained from them in how to prevent any contamination from occurring. This issue is serious enough that it could lead to the stopping of your project and the loss of a lot of money. This is because the local Council may be swayed by the action group to either limit the development to areas away from the high-energy yield ridgeline or not approve the project at all. Discussions are held immediately with the local shire planning officers, and a member from the action group and the botanist who undertook the flora survey are invited. At this meeting you put forward your position and that you understand the issues the Action Group are concerned about. However, you have come up with an alternative plan. You commit to a recovery program for the endangered species that involves the collection of seed from the remaining plants and their propogation under nursery conditions. Eventually this will lead to many thousands of the plants being grown and these will be sold with proceeds going to the ongoing environmental care of the remnant vegetation in the wind farm area. You have also negotiated for the purchase of a small section of the farm away from turbines in which you commit to rehabilitate with local flora species including the endangered plant. The botanist present believes that this strategy will lead to a significant increase in the number of rare species individuals and will go a long way to removing it from the endangered list. It is expected that this process will cost approximately $15,000. The Action Group member is very cautious and insists that the seed collection and propagation be undertaken and proved to be successful before construction commences. The botanist believes this is possible and, following another analysis of the project’s financials, you agree. At the following Council meeting the project is approved subject to nine conditions, one of which is the establishment of a rare species recovery program funded by the wind farm proponent and audited by the Council’s own environmental officer. This is written immediately into the project’s Environmental Management Plan. Exercise 14-2 Wind farm natural environmental issues – bat strikes during operation. Exercise 14-1 Wind farm natural environmental issues – flora and project approvals. Problem: Your wind farm has so far been two years in the planning and both a lucrative power purchase agreement and acceptable turbine supply contract have been negotiated and are ready to sign. The development is on cleared farmland except for a small ridge on the southwest corner that has remnant vegetation on it which was left by the farmer to prevent erosion during the heavy rains experienced in the area during winter. However, your analysis has shown that three of your best producing turbines will be on this ridge and if they are moved the subsequent loss of production (approximately $50,000 per year) could make the project un-financial. As part of your environmental approval you have undertaken a flora survey of the ridge and the results have shown that 7 individual plants of a rare species, which is the symbol of the local town, exist there and will be affected by the road design which your civil engineer states cannot change as the heavy transports will not be able to reach the area another way. This information is now public and a small but influential local action group are calling for the wind farm not to be approved at the next Council meeting because of this. What do you do? Problem: Your single 600kW wind turbine has now been operational for six months and so far has just exceeded your financial expectations. However, a local bird enthusiast has found a number of dead bats in the area, clearly coming from collisions with the turbine. It appears that the bats may be attracted to insects flying around the turbine who themselves are attracted by its aircraft navigation lights, a requirement of the local amateur flying school whose aerodrome is 4km from the wind farm and who were stiff wind turbine opponents. The local bat population is large and was always an issue with this wind farm, but such collisions are unexpected. What do you do? Solution: Discussions with an ornithologist suggest that the issue is not particularly significant but you are currently negotiating a new wind farm project close by and are concerned about public reaction. You have also committed to minimising such strikes in your environmental approval. The ornithologist’s original recommendations were to use a slow turning wind turbine as this would be better for echo location by bats, and hence collisions could be minimised. This was the primary reason for going for a single 600kW turbine instead of two 300kW units. There was also a recommendation to install high frequency but low power transmitters to deter bats from flying close by but you chose not to do so due to the expense. Solution: 14-21 14-22 You immediately contact the local environmental approval body and together with them and the local council discuss the issue. From this a number of possible strategies are identified. Suggestion 1. You are selling the electricity to the local retailer who has managed to on-sell this to a load that peaks during the daylight hours and is virtually non-existent during the night, and your wind farm power purchase agreement is conditional on maximising output during the day. The diurnal pattern of the wind resource is very good usually rising slowly during the morning to peak about 2:00pm and falling off around 7:00pm. Discussions with the turbine manufacturer have shown that the turbine can be programmed to lower its rotational speed at any time during operation. It could therefore be programmed to do so during the nighttime period and this should lead to a lowering in bat strikes. Suggestion 2. The amateur flying school only undertake nighttime flying during summer and the navigation lights were only installed to meet their concerns. The Civil Aviation Safety Authority (CASA), who formally approves such things, do not have any specific requirements for lights and do not require them as the wind turbines is outside the cone of approach to the aerodrome. Therefore the lights could be operated for the specific summer period only or turned off completely. Suggestion 3. The ornithologist recommendation is that the numbers of collisions are insignificant compared to the bats killed every year in the area due to car-strikes and transmission line electrocutions. Her advice is to monitor the situation further before taking any action. understood and commonly in practice. Most of these rely on technical studies to be described herein but it is worth pointing out that some degree of public communication must take place in a wind farm development and the developer and designer cannot be totally removed from this. You will need to talk, listen and respond to what people have to say. Provided the wind farm development fits into the definition of appropriate (a concept developed previously) there is little reason why it shouldn’t proceed. While the reality of wind farming is that social difficulties can arise, many studies have shown that communities that live with a wind farm do so very well (see for example Reference: 16 & Reference: 17) and the evidence in Australia largely confirms this. Figure 14-11 shows the artwork for the inaugural Festival of the Wind held biannually in the town of Esperance, Western Australia, where this countries first wind farm was built in 1987. Esperance has embraced wind energy as a symbol of the area and is justifiably proud of winds part in the Town’s history – after all, it was the first wind farm in Australia and many people even now still associate Esperance with its pioneering wind farming role. Figure 14-11 Festival of the wind held every two years in Esperance, Western Australia, to in part celebrate that communities use of wind energy. You analyse each option. Suggestion 1 has a significant cost implication even though the tariff is better during the day – it would significantly erode your profit to lower power output during the night. Suggestion 3 could prove very harmful for your future project and you believe it better to be pro-active environmentally than be seen to be only responding to public pressure – it is, after all, only a mater of time before the issue gets to the local newspapers. You therefore decide that Suggestion 2 offers the best solution. However, your insurer has suggested strongly that you either turn off the navigation lights completely or leave them on all the time. This is because the responsibility for the operation of the lights, and hence liability should there be a collision, is not clear and they believe the costs associated with defending your legal position could not be covered by you present insurance policy. Hence you decide to fall back to you original CASA approval and turn off the navigation lights. You advise the local newspaper that while you endeavoured to meet the requirements of the flying school you believe the bats are more important. You subsequently receive an environmental award for your project from the local bird association. 14.2 Dealing with community issues 14.2.1 The Clash of Wind Farms and Communities (Source: With compliments of Western Power) It could easily be construed from comments made in previous topics that wind farms are just about impossible to build, given the social issues that arise and the opposition these engender. After all, ask anyone whether they want to see more renewable energy produced and the answer will nearly always be “yes”, but ask them whether they would accept a large wind farm as their immediate neighbour and the answer become less clear. Ask yourself the same question and you may be surprised at your own response. Esperance is a remote community and people in such places tend to be much more philosophical about the resources available to them and how they use them. It makes perfect sense to them to be using an energy resource that is freely available and self-reliance can be a greater issue to them than the environmental benefits wind energy brings. Hence they welcome wind farming and there are few issues that cause real opposition. This section of the topic is about the social issues that arise in wind farm developments and how these are worked through. While engineers and developers can’t be expected to be social, planning or public relations experts, the same issues inevitably arise with wind developments and the tools to deal with them are well This is an interesting contrast to wind farms proposed nearer to more populated and urbanised areas. In such places the opposition to wind farms can be highly organised, passionate and effective (see for example (Reference: 18 & Reference: 13). Usually the arguments centre around unwanted change to an area or 14-23 14-24 landscape – often the most passionate opponents don’t actually live near the proposed wind farm and won’t see it, but they associate the development with a “loss” of amenity to an area which they obviously have some tie and don’t want to see changed. that a wind farm developer must quantify the landscape values and set about minimising the effect of the wind farm on these. Interestingly, many people opposing wind farms are also very environmentally aware and this creates real tensions between the environmental benefits of wind farming verses the social consequences of its use. Wind farms can, after all, be seen as a practical solution to sustainable development or a threat to the preservation of the landscape. Such a development can test an individual’s commitment to sustainability. Assessing a Landscapes Visual Amenity While wind farms can evoke such deep philosophical debates, in reality the social impact of a wind farm usually manifests itself in terms of four primary issues: − − − − A change to the visual amenity of an area Wind farm noise Electromagnetic interference from the turbines, and Shadow flicker from the turbines. While each wind farm is different and some of these issues will be irrelevant, it is worth spending some time assessing how each of these can affect the social environment and how these can be assessed. 14.2.2 The Main Issues and the means to address them 14.2.2.1 Visual Amenity Of all the issues facing wind farms in Australia, that of visual amenity is the most controversial, perhaps the most subjective and normally the most hard to quantify. While one person sees a wind farm as an unnatural blight on the landscape another can see it as an elegant and graceful thing in perfect harmony with the environment. Caught in between are the wind farm developers and designers who have to work with these varying opinions to complete a project. In some places wind farms have been disruptive to the visual environment and this was discussed previously in relation to some of the projects developed in the United States. Usually there is a factor of inexperience or naivety in this but sometimes the economics can so influence a development that its visual characteristics are usually ignored at the expense of the landscapes visual amenity or, at best, given scant regard. Wind farms have been built that are visually inappropriate in that they dominate and degrade an area so much that those qualities valued by users of the area have been ruined. This can create a great deal of dislike in a community for a wind farm development and has negatively influenced other projects even on opposite sides of the world, with some Australian projects seeing opposition groups siting the negative wind farm visual experiences from Northern Hemisphere projects. Fortunately, in Australia we are yet to see wind farm developments that have not taken landscape values and amenity into consideration and the industry here does involve such issues as a matter of course, see Reference 1. Often this involves a visual amenity expert, such as a landscape architect and this depends on the size of the project and the area to which it will be built. In assessing a landscapes value, it is often worth asking the local community through feedback forms (see for example (Reference: 20) and Figure 14-12) just what is important to them about an area, and then combining this with an independent experts opinion. The resulting assessment usually involves the issues given in Table 14-3. Figure 14-12 Public display held at the Esperance shopping centre for the then proposed Nine Mile Beach wind farm. Visual amenity is much more than just the look of a landscape. The term is used widely for all sorts of purposes but in its most general sense refers to the values, emotions and ties that people have to a place in terms of how they interact with it in a visual sense. Hence it involves emotional values and these differ from person to person and this can make visual amenity such a subjective thing. Why certain landscape views, commonly referred to as viewsheds, are important to a person depends upon that person’s experiences, cultural background, sex and age. There has been some work done on wind farm visual amenity issues in Australia and, interestingly, this had slightly different conclusions. (Reference: 19) found little evidence that there was a large difference between landscapes that people liked or disliked and that the impact of a wind farm on this can be assessed objectively. There was also evidence that prospective wind farm sites in Australia will largely be targeted on landscapes that are liked by the community – thus visual amenity appears potentially to be a very important issue for Australian projects. Wind farm developers and designers often miss the complexity of this issue. This is because their opinion of a landscapes value is coloured by their own perceptions and understanding that there are other opinions, and incorporating these into the project, only comes with project experience. What is certain is that a wind farm does take away part of what is a community asset, the visual amenity of an area. This means that the benefits of the project must compensate or at least be perceived to compensate that community for this. It also means 14-25 (Source: with compliments of Western Power) 14-26 Table 14-3 Issues considered when assessing the visual amenity of a proposed wind farm site. Issue Description Identification of views that are most important in the local community, the Identification and ranking broader community and for visitors. Identify actual position of view. Rank of key viewsheds in importance. Characterise the view viewsheds, produced by civil engineering design software during the visual assessment, and used to try and minimise the roads affect on that viewshed. Figure 14-13 Computer generated image of the road design for the Albany wind farm viewed from an identified key viewshed. The road was designed to minimise its visibility from this and other points. In terms of cultural, heritage, environmental or recreational uses. Identify elements landscape These elements are of a certain type, are separate, different and whole. Sometimes a viewshed can hold many landscape elements or only one. Formal documentation at the local or state level which gives guidelines or Policies or strategies laws in terms of protecting the visual amenity of an area. Once this assessment is complete, it is normal to then begin the assessment of the impact of the proposed wind farm on these issues. If planning guidelines or policies have been identified than these have to involve liaison with formal agencies, such as the local Council or environmental approval body. Sometimes these agencies require their own experts to assist in the assessment of the wind farm and they may make it mandatory to involve public displays so that the general public can assess the material. Wind Farm Design for the Visual Environment Once the landscape has been assessed the wind farm designer has the tricky task of designing a wind farm layout to meet the other technical constraints of the site. The wind turbines will have to be out in the open where the wind is and often at this stage there is a conflict between the energy yield and the effects on the visual amenity of the area. It is best for the designer to make some judgements at this stage, often using the expertise of landscape architects, to come up with a first stage design – usually this is one with acceptable energy yield – before taking this to the approval bodies or the general public for feedback. Developers are often scared of public opinion but much opposition to wind farms comes about because the developer has not even a first stage wind farm design to show people, and hence cannot answer peoples initial questions. Having been through a visual assessment and thought about the issues involves, often the first stage design is very well accepted and the public comments are more of relief than anything else – it is also a good way to show people that, as a developer, you are sympathetic to the values that the local community have. (Source: Western Power) In terms of the turbine placements, there are general principles that the wind farm designer can use to minimise the impact visually of the wind farm on the landscape. These are listed in Table 14–4. Good design visually is about using and being in sympathy with the characteristics of the landscape elements available. If the landscape is ordered, for example with long straight fence lines, rivers or buildings, then it makes sense visually to follow these with the turbine placements, see for example Figure 14-14. Alternatively, if the landscape is random, such as hills, then the wind farm can match this by varying the distances between turbines and placing them in a seemingly random manner, Figure 14-15. Figure 14-14 Example of a wind farm design which matches an ordered, straight landscape, here following a dyke on the Ijselmeer, The Netherlands. The wind farm design also has to include an assessment of how the following issues affect the visual amenity of the area; − − − − The size, numbers of and colours of the wind turbines The positioning of individual turbines and the spread of the wind farm, The visibility, colour and size of access tracks, and The visibility, colour and size of electrical infrastructure connecting the wind farm to the grid. It can come as a surprise that the wind turbines are not the only element in the wind farm that can have a negative visual affect. The internal wind farm roads, substations and overhead electrical lines for example are not as streamlined nor nearly as uniform as the wind turbines themselves and from a distance can make an enormous negative impact on the wind farms appeal. It is common practice for example to put all internal wind farm cabling underground and to design the roads so that they hug land contours as much as possible – Figure 14-13 for example shows an image of the road at the Albany wind farm from one of the key14-27 (Source: Photo courtesy of Paul Ebert) 14-28 Figure 14-15 Example of a wind farm design in a random landscape, here at the Windy Hill Wind Farm, Ravenshoe, Queensland. Note also the use of green graduated towers to match the green pastures. (Source: Photo courtesy of Western Power) The issues surrounding visual wind farm design are discussed further in References 17 & 13. Once the designer has arrived at a wind farm design, there are two main tools commonly in use to assess how it affects the landscape around the wind farm. These are; a) The “Seen Area Diagram” sometimes called “Zones of Visual Influence” (ZVI), and b) Photo and video montages (computer mock-ups) of the wind farm, sometimes called viewpoint analyses. Table 14-4 General visual amenity principles used when designing a wind farm. Design Principle Description If the landscape has straight, ordered elements then the wind farm design should follow, in sympathy, Matching landscape with these. If random, then turbines should be unevenly separated and at different heights following land contours. Use what topography you have to hide turbines from the viewsheds of most importance. Ensure that the Minimise affects on key design is a pleasing as possible from these viewsheds viewsheds and, if possible, enhances the landscape elements around it. Avoid mixing turbine sizes, types and colours. Make each wind farm on the same landscape Avoid clutter visually separate and a distinct element. Avoid turbine blades crossing when looking from key viewsheds. Put cabling inside the wind farm underground, and hide substations and roads by using the topography available. Colour roads and other structures in Hide ancillary structures sympathy with surrounding vegetation/background. Avoid road designs that lead to scaring or erosion, which can be visible for tens of kilometres. Landscape elements Turbine elegance Matching land use Distance Light Uniformity 14-29 Avoid cutting across separate landscape elements. Try and keep wind farm design to one element only. Avoid lattice towers in preference to smooth, slender tubular towers, and larger turbines in preference to many smaller units. Chose turbines that are sleek and visually appealing, while avoiding stocky designs with hard, square nacelles. Wind turbine positioning can be in sympathy with other structures (lighthouses, telecommunications towers etc.). Distance has an incredible effect on the visibility of turbines. Keep turbines as far away as possible from viewsheds of importance. The sun at sunrise and sunset can make wind turbines very visible in a landscape. Avoid glossy paints in preference to matt finishes. Use a colour for the turbines that matches the background when viewed from the key viewsheds. All turbines should be the same colouring. Avoid large-scale advertising on turbines. 14-30 Seen Area Diagrams (sometimes called Zones of Visual Influence ZVI) A Seen Area Diagram is essentially a map that shows where in the landscape you can see wind turbines from, for the proposed wind farm design. An example is shown in Figure 14-16 for the Albany wind farm, which was put together for that project’s environmental assessment and which shows the number of wind turbine nacelles visible 2m above the ground within the map extents for the given wind farm design. Figure 14-16 Example Seen Area Diagram (ZVI) shown for the Albany wind farm. Colours are the number of wind turbine nacelles visible from that location. Computer packages are available which can undertake this work easily using digital terrain information and the dimensions of the wind turbines. Figure 14-17 shows a photomontage created for the Albany wind farm from the top of Mt Clarence, Albany, a well know tourist lookout. The figure also shows the actual finished wind farm as built and, while the images differ in season, the turbines were very well represented in the montage and the final effect is very similar to that estimated. Figure 14-17 Example of a wind farm photomontage undertaken for the Albany wind farm, shown together with the actual as built image. (Source: Image courtesy of Western Power) Seen Area Diagrams are extremely useful to show what areas are affected visually. In Figure 14-16 an area of land to the southeast of the proposed wind farm was visually sensitive and the seen area diagram showed that key viewsheds there had been protected by this wind farm design. Especially for the general public, such diagrams give a much better understanding of where in their area they will be able to see the turbines and are typically produced in terms of the numbers of nacelles of blade tip azimuths visible. Seen Area Diagrams are nearly always produced using computer simulation packages as the computations for a land area, such as that shown in Figure 14-16 (40km x 25km), would be difficult to do manually. Such computations rely on topographical information and ignore landscape features such as vegetation and buildings and the influence of site conditions such as the weather. Hence, a site assessment has to be done which reveals how the wind farm will actually looks on site, and this leads to the second assessment tool, the photomontage. Computer Photomontages & Videomontages (viewpoint analysis) Viewpoint analysis is usually undertaken from key viewshed locations in order to quantify what the wind turbines will look like on the landscape. Usually photographs are taken from the location in question and the wind turbines are introduced digitally into the image in the locations proposed (called a photomontage). This can also be done with video or using a computer the turbine rotors can be turned to simulate in real life what to expect (called a videomontage). 14-31 (Source: Photos courtesy of Western Power) 14-32 This type of analyses can also be done to show the effect of weather on the wind farm visually, by taking images at various times of the day and various weather conditions. However, skill is required by the digital manipulator to ensure that what is shown is realistic and this only comes from a graphic designer or very experienced wind farm designer. Unfortunately, image manipulation is so easy that wind farm opponents can also show their versions of the same images and often they can exaggerate the look of the wind farm for their own purposes. However, the wind farm designer should never attempt to cover over the visual impact of a wind farm design as if the wind farm is built the error will be obvious to everyone. This will make the next wind farm just that much harder and damage the industry. through the air particularly calming. People’s hearing ability in terns of loudness and frequency range also varies enormously and this makes the impact different for each person. Typically, the wind farm designer has to do three things to ascertain whether the noise from a wind farm will be acceptable: 1. Measure the background noise levels at various locations around the proposed wind farm area which are known to be noise sensitive (usually called noise sensitive premises), 2. Model the noise emitted from the wind farm to estimate the increased levels at those locations, and 3. Compare the increased levels with maximum allowable values set by Statutory bodies. Before outlining how these three are undertaken it is worth describing what noise is and how a wind turbine creates it. Quantifying Visual Effect Once the seen area diagrams and photomontage work is completed it is then necessary to quantify the visual impact according to the values identified in the landscape’s visual assessment. Typically, this is done by categorising the impact as low, medium or high, depending on the number of turbines visible and their distances away from the area being viewed. Following this, a decisions needs to be made through some form of public process whether these are acceptable or not. For example, the categorisation over a residential area may be high impact and yet the majority of residents who live there really don’t care, or the categorisation over a sensitive lookout may be medium yet the local council will not accept that level of visual disturbance to what is their premier tourism attraction. Often the wind farm designer will need to iterate the design and produce many versions before consensus can be reached on whether an acceptable wind farm, visually, can be built. If no consensus can be reached then often it is necessary to involve a higher level of arbitration, sometimes a State Planning Authority, who can make rulings on visual impacts. This latter option is often the case if area of particular visual sensitivity are involved such as National Parks or areas of great natural beauty. The wind farm designer must be particularly careful when considering wind farms close to such visual community assets. What is sound and noise? In its purest form, sound can be thought of as small scale and rapid fluctuations in pressure with the frequency of these giving the particular note or pitch. These fluctuations are produced when an amount of energy is released into the air causing it to vibrate. The human ear can pick up sounds between about 20Hz to 20,000Hz (20kHz) and at any one time a person is usually hearing sound at a variety of frequencies from multiple sources. According to Reference: 15, when sounds become irritating and unwanted you have what some people call noise. Wind turbine noise is usually described using two measures, the first being the sound power level LW defined as: Equation 14-1 14.2.2.2 Wind Farm Noise Wind turbines create noise and it is wrong to say otherwise. Whether that sound is unacceptable, whether it creates disturbance or whether it is inappropriate for a locality depends on many issues but what is clear is that this issue is one that the wind farm developer and designer have to take seriously. It is in most wind farm projects, after all, second only to visual amenity in the social agenda. Wind farms have been built that have caused unacceptable and unwanted noise intrusion to communities, see Reference 13, but, on the whole, most people are amazed at how quiet modern wind turbines are and if designed correctly people can live peacefully within a few hundred metres of operating turbines. The science of noise and how it applies to wind turbines is a complicated thing and there is not the time in this topic to fully describe it. However, over the years the wind farming industry has studied this issue in great detail to ascertain where the noise from a wind turbine comes from and how to control and minimise this. Such work has resulted in some standard practices for assessing this noise and trying to come to terms with how this affects people who live close to wind turbines and these will be briefly outlined here. (Reference: 21) gives a good overall discussion of the issues in relation to wind turbines. where W is the source sound power and Wo is a reference sound power (usually 10-12 watts) that describes the total acoustic power emitted by the noise source, and the second is the sound pressure level LP defined as; Equation 14-2 where p is the instantaneous sound pressure and po a reference sound pressure (usually 20 x 10-5). For a wind turbine, LW relates to the amount of sound being emitted at the turbine while LP relates to what someone can hear at some distance away from the turbine. Figure 14–18 gives some examples of sound pressure levels for everyday things. Like visual amenity, noise can be a subjective issue. For example, some people will not tolerate any noise disturbance at a locality regardless of its intensity while others will find the gentle swishing of the blades 14-33 14-34 Figure 14-18 Sound pressure levels for everyday things. where α is known as the sound absorption coefficient (a good estimate for broad-band sound is α = 0.005 dB(A)/m). This equation assumes what is known as hemispherical noise propagation that essentially means that the sound pressure level is the same at all radii above ground and away from the turbine. In reality sound is more complex and the noise heard varies depending on where you are in relation to the wind turbine, although Equation 14-3 gives a reasonable estimate. Often you can stand at the base of a large turbine and hear very little but move out from the base of the machine and the sound levels at first rise before falling away. There is also a difference in sound pressure at upwind and downwind locations and in a wind farm the noise at a point is a combination of pressures from all the surrounding turbines. An estimate of the combined sound pressure level Ltotal at a point surrounded by N turbines can be made by combining the N sound pressure levels at that point due to each, as: Equation 14-4 where Li is the sound pressure level due to turbine i. The noise from a wind turbine Obviously some knowledge of LW means that estimates can be made of LP at points surrounding the wind farm. Estimating LW for operational wind turbines is done using techniques and standards that attempt to normalise the way the values are read such that they can be used in a wide range of applications. The International Energy Agency (IEA) and the International Electrotechnical Commission (IEC) are examples of the bodies that set such standards. Wind turbines make noise from a variety of sources and these can be classified simply as mechanical, electrical and aerodynamic. Mechanical noise is generated by gears, motors and cooling fans and is typically of a certain frequency which means the sound generated is tonal (of a certain clearly recognisable singular tone). Such noise can be very penetrating and can stand out from background noise, which is usually broad spectrum. Such mechanical noise can be lowered by sound proofing, by installing vibration isolators and by paying particular attention in the manufacturing process to the quality of gear train machining. (Source: To be confirmed) Both LW and LP have the logarithmic unit of decibels (dB). A change in sound level of 5 dB can usually be noticed by just about everyone while that of 10dB sees a doubling in the loudness of the sound, which is very obvious. While the human ear can hear over a large frequency range it usually does so better at some frequencies than others. When measuring noise, to best predict the effect of the noise source on people measurements are usually taken using a special filter which attenuates lower frequencies – this is known as A filtering and values are expressed as dB(A). The amount of sound pressure at a location at some distance R from a wind turbine depends on the sound power level emitted by the turbine, the sound absorption (sometimes called attenuation) in the air, the terrain complexity, the type of ground cover and the weather, but can be described by a very simple model as: Equation 14-3 Electrical noise is usually associated with the hum from transformers and a very high-pitched whistle from power electronics such as inverters. Again, such noise can stand out easily from background noise and is usually overcome with soundproofing and installing lower-loss transformers. Aerodynamic noise is much more complex and can generally be characterised as low frequency, noise associated with turbulence and noise directly from the aerofoil. Low-frequency noise can be generated by wind shear or for downwind configurations, when the blade hits the wake of the tower and is nearly always dominated by frequencies associate with the blade passing frequency, typically up to 3Hz. While not heard by the human ear such noise can lead to vibrations in buildings and can be overcome by increasing the distance of the blades from the tower. Turbulence related noise is experienced by the observer as a blade “swish” and usually is around the 1000Hz frequency. Similar to this is aerofoil noise, which is a product of the boundary layer flow over the blade 14-35 14-36 section and can be influenced by the shape of the blade tip (some turbines have unusual tip shapes because of this), a blunt blade trailing edge and surface imperfections. This latter reason is usually why, before the rotor is lifted into position, a great deal of time is spent cleaning and checking the blades as even small imperfections can give rise to very annoying blade “whistling”. Figure 14-19 Background noise levels being measured for a wind farm. Typically the faster the blades go the more turbulence and aerofoil noise is produced, and hence very large MW sized turbines usually are quieter than very small machines with sound pressure levels around 95 to 105 dB(A). Variable and constant speed turbines also have different sound outputs with some preferring variable speed as these have lower rotational speed in lighter winds when the background noise is low. Wind turbine manufacturers normally can provide sound power levels for their turbines at different wind speeds and often they can provide this information broken into spectral information (varying frequencies). This latter information makes it possible to ascertain whether that turbine has a particular tonal noise problem around one particular frequency. It is also useful to have an empirical relationship for LW so that estimates can be made on a “rule of thumb” basis for any machines. Efforts have been made to arrive at such relationships and while some of these models can be complex, a good estimate can be made using the following equation from Reference: 15 being: (Source: Courtesy of Western Power) Figure 14-20 Measured background noise levels and estimates of noise with wind farm operating for the Albany wind farm. Equation 14-5 where Vtip is the tip speed of the rotor in m/s, and D is the rotor diameter, with results in dB(A). Hence, for a MW sized turbine with a 60m rotor, turning at 20 RPM (Vtip = 63 m/s), the estimated sound power level would be 103.6 dB(A) which compares favourably with available machines of this size. Estimating wind farm noise and gaining approvals Provided the wind turbine chosen has sound power level information available, it is possible to reasonably accurately predict the noise levels surrounding a proposed wind farm. In principal the equations above provide a very simple check but in practice regulatory bodies in Australia require a more thorough approach, see for example (Reference: 22). For large wind farms it is normal practice to measure background noise levels surrounding a wind farm at noise sensitive locations and then model the wind farm noise to see what the addition of the turbines contributes to the noise at those points. Figure 14–19 shows this been carried out for a wind farm in Western Australia. Measurements are usually made over a certain time period and are described as: • • LX. These sound pressures are exceed X% of the time (i.e. L90 exceeded 90% of the time), and Leq. The average sound pressure over the sampling interval, which represents the same amount of energy as the varying sound level being recorded. with a 10-minute averaging period usually used. This can be correlated back to wind speed measured at the hub height of the turbine and hence a graph of background sound pressure level at that point verse wind speed can be made. (Source: Courtesy of Western Power) Estimations of wind farm noise are usually done using software packages and often involve an acoustic expert or someone experienced in wind farm noise. Figure 14–21 shows the results of one such modelling package, which gives the sound pressure level contours in dB(A) due to the wind farm operating at 8 m/s wind speeds. Such packages take into account the terrain and other attenuation influences. Figure 14-20 shows one such graph for the Albany wind farm in Western Australia. 14-37 14-38 Figure 14-21 Example estimations of wind farm noise output for the Nine Mile Beach wind farm, Esperance. 14.2.2.3 Electromagnetic Interference The use of devices that rely on the transmission and reception of electromagnetic radiation is widespread and we take it for granted that such things are available at any time. Such devices include mobile phones, televisions, and radios as well as microwave transmissions and civil and defence radar. However, the quality of reception of such devices can be impacted on by structures that interfere with either the transmission or the reception and, occasionally, this happens with wind turbines. Wind turbines themselves produce electromagnetic radiation from their generator, transformers and other electrical infrastructures but normally this is well shielded and unmeasurable at a distance of 100m from the machines. While debate still rages about the long term health affects of living near power lines, criticism launched at wind turbines by wind farm opponents because of this issue is largely wrong as their electromagnetic output is small compared to other everyday sources, such as television sets. However, rather than producing the signal itself electromagnetic affects of wind turbines are usually associated with interference to other signals. It is not so surprising that this problem arises often as a location that is good for wind farming – high with open fetch – is also good for telecommunications equipment. In general terms the magnitude of the effect on such signals is dependent on, • • • • • • The type and size of wind turbine, Rotational speed of rotor, Rotor planform and yaw angle, Blade and hub construction material, Surface contamination (ice and water), and Internal metallic components such as lightning conductors in the blades. Interference occurs when the wind turbines cause scattering of the signal and often modulation of that signal at the blade passing frequency. Television interference can be seen for example as ghosting (caused by backscattering when a signal is reflected off a wind turbine) and fading (caused by forward scattering when the wind turbine interrupts the signal). (Source: Courtesy of Western Power) Once estimated noise is known it is “added” to the background noise levels to arrive at a total predicted noise at the point of interest. Figure 14-20 has this shown as well as a line of allowable sound pressure stipulated in this case by the Western Australian Environmental Protection Authority who’s regulations state that the wind farm noise could not exceed 40dB(A) or 5dB(A) above the background noise level, whichever was highest, at a noise sensitive premise. At this particular measurement point, a nearby residence, the predicted noise levels can be seen in the graph to be way under the measured background noise levels and at this location the wind farm was ultimately not audible. Allowable noise limits vary across Australia and References: 13, 14 & 15 give examples for other countries. Reference: 1 also gives further industry guidelines for dealing with noise issues in Australian wind farm projects. It should be stated that electromagnetic interference from operational wind turbines is uncommon and, where it does occur, other structures usually also have similar interference problems. In some circumstances wind farms have been implicated in affects on television, FM and AM radio, aircraft navigation and radio, and microwave systems. As yet there appears to be no evidence of such affects on cellular phone or satellite systems. Electromagnetic interference is a complex issue far beyond the scope of this topic to discuss in detail, although methods do exist which are used to model and predict such interference from wind turbines, see References: 15 &Reference: 14. Where a nuisance problem exists it is often easily overcome; for example, if a few local residents have television reception problems then a better aerial can be bought for them or they can be given satellite receivers at little cost to the wind farm developer. Where a potentially major interference problem exists, such as military or aircraft navigation installations, it may be better for the wind arm developer to look elsewhere or engage an expert to appraise the situation. 14-39 14-40 14.2.2.4 Shadow Flicker Figure 14-22 General map of the Esperance area showing previous and proposed wind farm installations relative to the town. Shadow flicker is a term used by the wind turbine industry to define a problem that sometimes occurs when sunlight travels through or reflects off an operating wind turbine’s blades causing a stroboscopic effect at close-by residences. Most people find a flickering fluorescent light tube particularly annoying and the effects from the wind turbine can be similar. At first glance this problem appears trivial. After all, it is likely to only affect a given location for less than 30 minutes per day, only in strong sunlight conditions, and will be seasonal as the sun changes altitude through summer and winter. However, it is generally not pleasant if you have to live with the effect and some people can have dramatic physiological responses to such “strobing” light that in extreme circumstances can lead to seizures and epileptic fits. The problem has had significance in northern Europe where the sun can be very low on the horizon for long periods of time. It has not been a major issue in the United States nor has it arisen as a major problem in Australia. Where it does cause concern wind farm designers have very accurate data available from the Bureau of Meteorology on the suns position and it is possible to accurately predict what properties will be at risk and to site turbine appropriately Properties closer to wind turbines are also more likely to experience real problems from shadow flicker and a general rule of thumb is to keep turbines a minimum of 10 rotor diameters away. At such distances the effect is almost impossible to discern. If the problem is still not alleviated then for the short period of time when it occurs the problem turbine(s) can be turned off. The use of non-reflective paint is also advantageous in general to reduce light reflections. Visual Amenity Case study –Nine Mile Beach wind farm, Esperance, Western Australia Situation: The Nine Mile Beach wind farm was designed in 2002 to consist of six 600kW turbines to deliver electricity into the remote township of Esperance, Western Australia. The community had already experienced wind farming through two previous installations, the Salmon Beach wind farm consisting of six 60kW wind turbines and the Ten Mile Lagoon wind farm consisting of nine 225kW machines. Their relative position in relation to the town is shown in Figure 14–22. What general principles were used to design the new wind farm? (Source: Courtesy of Western Power) Solution: Esperance is a community that sits on a coastline that is renowned for its great natural beauty. Fortunately, at the time of design the existing two wind farms were very well accepted and the town was used to and familiar with the technology. A decision had been made to decommission the Salmon beach facility and in a visual sense it was suitable to replace those six machines with the same number in the new wind farm. A study of the wind resource and electrical infrastructure available found that an area of land adjacent to the existing Ten Mile Lagoon facility would provide the best technical and financial wind farm placement. This area is shown in Figure 14–22. It was proposed to build the new facility at the eastern edge of this area at a locality known as Nine Mile Beach and hence the new wind farm was named after this. Visually, this area would affect similar viewsheds to the existing facility but since an existing wind farm already affected these, the visual impact would be less than areas not affected previously. A key viewshed, that from a lookout at Wireless Hill (shown in Figure 14–22) was identified as particularly important and would have to be protected. In consultation with the community another key area of recreation, Observatory Point, would also have to be protected visually. The Nine Mile Beach wind farm was therefore designed with the following visual concepts: • • • 14-41 Generally it is not acceptable visually to mix wind turbine types and sizes so a distinct wind farm, visually separated from the Ten Mile Lagoon facility, was proposed, Similarly proportioned wind turbines were proposed (i.e. blade diameter to turbine tower height) to match the existing man-made elements in the landscape, Siting of the new turbines were in a random pattern which mimicked the spacing of the Ten Mile Lagoon Turbines, 14-42 • • When viewed from the Wireless Hill lookout, alignment of the new turbines roughly coincided with the old machines at Salmon Beach so as to limit the long-term visual impact on the Wireless Hill lookout, and To limit the amount of visual disturbance to the tourist loop road which followed the coastline out and around the wind farm site, and the Observatory Point recreation area, wind turbines were positioned to use screening topography and distance as much as possible to hide machines. Turbines were also positioned such that, from the tourist road, only glimpses of turbines were possible when close to the site. The new wind farm design was tested visually using Seen Area Diagrams and photomontages, which were presented to the Esperance community and approval bodies during the project’s feasibility study. A before photograph and after photomontage from the Wireless Hill lookout is shown in Figure 14-23 with the Salmon beach turbines removed and the Nine Mile beach turbines added in the latter to show the overall long term visual affect. Figure 14-23 A before and after shot from the Wireless Hill lookout towards the town’s wind farms, including a photomontage of the proposed Nine Mile beach wind farm facility. 4.Results of the hearing into the Toora Wind Farm before the Victorian Civil and Administrative Tribunal, 20-29 November 2000. 5. “Attachment to the Development Application to The City of Albany for the Albany Wind Farm”, Western Power, February 2000 6. “Western Power Corporation, City of Albany, Proposed Albany Wind Farm, Environmental and Reserve Management Plan”, Halpern Glick Maunsell, February 2000. 7. “Western Power Corporation, Albany Wind Farm Feasibility Study, Environmental Assessment”, Halpern Glick Maunsell, document ES995271, February 2000 8. “Referral to the Department of Environmental Protection for the Esperance Nine Mile Beach Wind Farm”, Western Power, May 2002. 9. “Environmental Impact Study for the Crookwell Wind Farm”, Pacific Power, August 1997. 10. Referral to Environment Australia under the EPBC Act for the proposed Musselroe Wind Farm, Tasmania, by Hydro Tasmania, May, 2002. 11. Referral to Environment Australia under the EPBC Act for the Yabmana Wind Farm, South Australia, by Wind Prospect Pty Ltd, December 2001. 12. Polacheck, J. S. 2002 “Cape Cod: Twisting in the Wind”, Public Utilities Fortnightly, May 15. 13. Gipe, P. (1995) “Wind Energy Comes of Age”, Wiley & Sons 14. Burton, T., Sharpe, D., Jenkins, N. and Bossanyi, E. (2001) “Wind Energy Handbook”, Wiley & Sons. 15. Manwell, J.F., McGowan, J.G. & Rogers, A.L. (2002) “Wind Energy Explained: Theory, Design and Application”, Wiley & Sons. 16. “Public Attitudes towards Wind Farms in Scotland”, Development Department Research Programme Research Findings No. 93, Scottish Executive Central Research Unit, 1999. 17.Pasqualetti, M., Gipe, P. & Righter, R. “Wind Power in View: Energy Landscapes in a Crowded World”, Academic Press, 2002. 18.Ebert, P. R. 1999 “Stakeholder Management. Ignore it and your wind farm may never happen.”, Proceedings of the Australian Wind Energy Conference, June 28-30, 1999, Newcastle, Australia, pp. 44-50. 19.Lothian, A. 2002 “National Assessment of the Visual Impact of Wind Farms”, Proceedings of the Australian Wind Energy Association Conference, July 23-26, Glenelg, South Australia. 20. “Nine Mile Beach Wind Farm Feasibility Study – Public Display Response From”, Western Power, 2002. 21. McKenzie, A. R. 2002 “Wind Turbine Noise Issues: Application of Overseas Experience to the Australian Market”, Proceedings of the Australian Wind Energy Association Conference, 23-26 July, Glenelg, South Australia. (Source: Courtesy of Western Power) 22. “Wind Farms, Environmental Noise Guidelines, Draft 2”, South Australian Environmental Protection Authority, July 2002. References: 1.“Best Practice Guidelines for Implementation of Wind Energy Projects in Australia”, The Australian Wind Energy Association, 2002. 2.Kahn, R. D. “Siting Struggles: The Unique Challenge of Permitting Renewable Energy Power Plants”, The Electricity Journal, March 2000. 3. “Policy and planning guidelines for development of wind energy facilities in Victoria”, Victorian Government publication, 2002. 14-43 14-44 ...
View Full Document

This note was uploaded on 06/09/2011 for the course PV 5053 taught by Professor Aasd during the Three '11 term at University of New South Wales.

Ask a homework question - tutors are online