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The development of a wind energy project is a long and complex process, involving – depending on the size of the project – the assessment of technical, economical, environmental, legal and political issues.
| Although a lot of expertise is needed to conduct the necessary assessments and to evolve an appropriate project layout, as a central task the developer has to bear in mind and control the conduction of the basic steps of wind energy development.
This article describes the activities to be done, but does not give step-by-step solutions, because the framework conditions of projects vary case by case. The content of the article is based on the project course proposed by Gasch/Twele (2010). The best practice guidelines for wind energy development by the European Wind Energy Association (EWEA) as well as the similar guidelines of the British Wind Energy Association (BWEA) are used for completion of the contents.
This overview of the various aspects that play a role in the development of wind energy projects should be read as an introductory summary for the wind portal. All issues mentioned here will be described in detail in the specific articles.
Pilot Study / Initial Site Selection
The initial site selection is the first phase in the development of any wind energy project. In this phase appropriate sites should be identified and their wind potentials should be estimated. By identifying environmental, technical, commercial and political constraints of the sites the project developer can decide whether a more extensive feasibility study should be conducted. As a starting point many developers visit the possible project sites, gathering first impressions about topography and infrastructure (roads, dwellings, grid-connection). As a central task in this phase, available environmental and technical data must be collected.
The 'desk-based' studies for site selection are conducted to decide whether site characteristics fulfill crucial technical criteria for the successful development of a wind project.
- The developer will usually identify sites with sufficient potential for a suitable wind resource by using a combination of maps of the area, results of computer modelling, meteorological offices (airports, harbors, farming), or data from university departments dealing with wind energy. Promising values are average wind speeds above 6 m/s. Characteristics of other wind parks in the area have to be investigated.
- The local road network must be suitable to provide access for large transportation vessels. An initial investigation will give a first idea of the necessary extensions for the wind project.
- Site ownership must be considered
- Grid connection must be available in an appropriate distance to keep connection costs low.
Considerations about Legal Aspects for the Site Selection
The initial questions related to legal aspects of the project development concern the environmental status of the area. To gain information about the feasibility of a wind project within the constraints of environmental protection at potential sites, the developer has to consult local planning authorities for reports, maps and studies about the environmental status of the proposed site: This status includes information about ecological designations concerning areas or protected species. Due to the relatively long time period necessary for developing a wind project, also changes in the environmental policy and planned but not yet realised protected areas have to be taken into account. Besides this 'purely environmental' issues the considerations have to cover the following aspects of the site:
- Visual Aspects: The visibility of the proposed project from important public viewpoints has to be checked.
- The distance to domestic dwellings should be sufficient to avoid disturbance of the inhabitants by noise, shadow flicker, visual domination or reflected light.
- Recreational uses: Development plans of local planning authorities have to be checked for sites and areas dedicated to recreational use.
- Civil and military airports: local airport authority have to be consulted.
- Proximity of Archaeological / historical heritage sites could be constraints for the development of a wind project
- Telecommunications: As wind turbines can affect microwave connections, TV, radar or radio transmissions adversely, position of masts and other infrastructure must be investigated.
- Restricted areas: military installations but also telecommunications installations can be reasons for restrictions for the development of wind projects in the surrounding area
Economic considerations during this earliest phase of the project concern the search for potential investors and the estimation of the potential equity available for the project.
Dialogue and Consultation
At this stage of a project, dialogue with local authorities has to be opened to gather information and to define the major issues related to the planning process which have to be discussed in more detail in the following planning phases. The officers of the local authorities may also recommend other consultants with experiences in wind energy development in the area. The focus of the consultation for site selection is gathering and distributing information.
- Evaluation of the quality of wind data collected during the pilot study: Based on the outcome of this evaluation the developer has to decide, whether own wind measurements are necessary for reliability of the estimation of the expected profits of the project.
- Common and established methods for site evaluation should be applied (see Resource analysis)
- Wind speed distribution is measured for an appropriate period of time (minimum one year, in case no other reliable sources are available). Measurement for large wind projects requires installation of masts of heights about 60 m. For the placement of these masts an own planning application is often necessary. This process extends the project development significantly. As small differences in the prediction of wind speed distribution causes large changes in potential wind energy yield, a measurement campaign is essential to create sufficient reliability for potential investors.
The soil conditions are assessed to define basement types: Flat basements can be used in case of solid ground conditions but in for soft soil pile basements may be necessary. Each proposed placement site of a turbine tower needs an own survey.
A very important part of the site evaluation is the development of a detailed description of possible environmental impacts of the wind project. In European countries planning authorities often request an environmental statement, containing a number of assessments concerning the following environmental issues
- Justification of the site selection
- Visual and landscape assessment - Description of the landscape and the possible impact of the project
- Assessment of the noise generated by the wind turbines - conclusions for the chosen distance to domestic dwellings
- Ecological assessment
- Archaelogical assessment
- Hydrological assessment
- Interference with telecommunications systems
- Aircraft safety
- Safety Assessment - technical description of the integrity of the chosen turbines for the site
- Traffic management and construction - like the impact of the wind turbines the construction of the access roads has to be discussed with local authorities
- Electrical connection
- Effects on the local economy
- Tourism and recreational effects
- Global environmental effects - By the estimation of the energy yield of a project, the expected avoided emissions can be estimated.
- Decommissioning - The environmental statement must contain considerations about removal of the wind turbines and the related restoration processes of the landscape after the project period
The local electricity distribution system has to be examined by available plans and consultation of the local electricity company. The dialogue with this company reveals whether an electrical connection to the sites under consideration is technically and commercially feasible, because the company can give an indication of the likely costs of the wind project connection to the grid. ► Grid Portal on energypedia
Planning Wind Projects
- Wind park layout is planned based on wind speed distribution, surface parameters and environmental conditions. Type and rating of wind turbines are selected and the layout is optimized by computer tools concerning the expected output. Besides output, installation of connection lines and (possible) transformer station as well as construction of roads for installation and service of the wind park are essential criteria for the project layout.
- The outcome of soil surveys indicates, whether the optimal placements determined by modelling can be realised.
WEC / Grid
- The choice of number, type and rated power is influenced by available grid capacity at the site. The cost of building a transformer station or long grid connections have to be evaluated as initial costs in comparison to expected profits.
- The calculation is a complex optimisation depending on costs of the turbines, cost of grid connection and profits depending on expected wind conditions.
All costs related to the proposed layout have to be evaluated including wind turbines, basements, grid-connection, road construction, planning and monitoring of the construction process, advice about legal and tax conditions, cost of planning, project approval and environmental studies. Examination of possible support mechanisms (political framework conditions like feed-in tariffs or other funding mechanisms). Clean Development Mechanism (CDM) baseline studies can be prepared in case access to CDM is an option.
Type of Company
The legal body for the operation of the wind project must be chosen: The choice depends partly on the number of people involved in the project. In general a larger number of people (e.g. a community as a whole) is a great advantage for the development of the wind project. A limited liability, a co-operative, or a joint-venture with a local energy company are feasible alternatives
All relevant data of the wind project is combined to evaluate the economical feasibility of the wind project:
- wind speed distribution and expected energy yield
- expected feed-in returns
- Initial investment costs for the proposed project layout
- Annual costs for financing
- Annual costs for maintainance
The expected annual profit is calculated by comparison of costs and returns of the project. Additionally the overall profit is calculated by summing up the annual profits over project lifetime.
Building Application and Environmental Impact Review
After all detailed technical, economical and environmental assessments are completed the project developer may submit a planning application to the local planning authorities. This application is normally submitted in combination with the environmental statement describing the outcome of all assessments conducted by the product developer. With the submission of the application, the project developer starts a phase of discussion and co-operation:
- The planning application has to be made available to the public to allow inspection and response.
- Based on the environmental statements, the planning authorities may implement additional regulations concerning noise control, traffic safety, decommissioning and restoration, interferences with telecommunications, ecological impacts as well as the design and colour of the turbines.
- If the project developer and the planning authorities close discussion with a suitable outcome and the requested changes in the project development are implemented, the planning application is approved and the project permission is granted.
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Gasch, R. and Twele, J. (2010) Windkraftanlagen - Grundlagen, Entwurf, Planung und Betrieb, Vieweg+Teubner
- ↑ European Wind Energy Association (1999) Best practice guidelines for wind energy development, retrieved 9.7.2011 []
- ↑ 3.0 3.1 3.2 British Wind Energy Association (1994) Best practice guidelines for wind energy development, retrieved 9.7.2011 []
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 European Wind Energy Association (1999) Best Practice Guidelines for Wind Energy Development, retrieved 8.7.2011, []