Section
Segment

The choice of wind turbine for a particular area is dependent upon the wind conditions within that area, feasibility of the turbine and access to the area. The wind turbines located within areas of high wind force are designed to withstand heavy storms and to utilise energy more efficiently with higher wind speeds.

Segment

Areas are divided into three categories: Categories I, II and III, according to an international standard. Each category outlines the wind patterns that each turbine must operate within in order to generate electricity throughout its lifetime. Higher categories are designed for lower wind speeds and gusts.

Segment

Category I

High wind speeds

  • Mean wind speed per year:

     10 m/s

  • Wind gusts:

    70 m/s

Category II

Average wind speeds

  • Mean wind speed per year: 8,5 m/s
  • Wind gusts: 59,2 m/s

Category III

Low wind speeds

  • Mean wind speed per year: 7,5 m/s
  • Wind gusts:52,5 m/s
Segment

The table above shows how the areas are categorised according to yearly averages for wind speeds and wind gusts. The main objective of this categorisation is to secure the greatest amount of energy in each area for the lowest cost. Wind turbines in category II usually have longer blades than wind turbines in category I. This means that they can produce more energy at lower wind speeds but are also designed for weaker storms and wind gusts.

Wind turbines are categorised according to wind characteristics (according to the international standard). Measurements within the area have shown that the Búrfell Wind Farm would be categorised as category I; therefore, the area is suitable to be fitted with turbines that withstand storms and high wind gusts while depending on higher wind speeds for general electricity production.

Segment

Power capacity

Wind turbines with a capacity of over 3.0 MW are the highest rated option available for use in the area that can also withstand the weather conditions at Búrfell. Initial calculations indicate that wind turbines with a 3.0 – 3.5 MW capacity are suitable for the wind farm.

Segment

Number of wind turbines

The number of wind turbines would be approximately 58 with a 3.5 MW unit capacity and 67 with a 3.0 MW unit capacity.

Section
Spila myndskeið
Segment

Size of wind turbines

Each Turbine will have a maximum height of 150 m to the tip of the blade. This can be compared to Landsvirkjun’s research wind turbines that stand at 77 m in height.

Section
Segment

Foundation

Wind turbine foundations for the mentioned wind turbine sizes are, in most cases, circular or octagonal with a diameter up to 25 m. The foundation will be below ground and only the uppermost section will be visible. The extent of the foundation and platform can be seen at the site of the two research wind turbines. The layout of the wind turbines in the Búrfell Wind Farm would be similar, but the foundation and platform would be on a larger scale.

Concrete work on the foundation for the current research wind turbines

Section
Segment

Wind turbine lighting systems

Aviation obstruction lighting was installed on Landsvirkjun’s research wind turbines in the Haf area after consultation with the Icelandic Aviation authority (ISAVIA). The assessment process and feedback from the operation of the research wind turbines has revealed that the aviation obstruction lighting has a visual impact on the area. The need for lighting of this nature is being reconsidered since aircrafts are forbidden to fly below 150 m in this area according to aviation regulation No. 770/2010. Requirements for this feature differ between countries and location of wind turbines (i.e. if they are located offshore or onshore.) The height of wind turbines is relevant in this discussion, as is the turbines’ proximity to airports and well-known flight paths.

Landsvirkjun recommends compliance with the criteria used in Scotland and the UK. This would mean that wind turbines under a height of 150 m that are located at least 15 km from airports and main routes should not be specially marked with air safety lights. This arrangement would be considered satisfactory with respect to aviation safety. The discontinuance of the use of aviation obstruction lighting on the wind turbines would accommodate complaints about the visual impact of the lights after dark. In the event that aviation obstruction lighting is required, Landsvirkjun will place an emphasis on only marking the wind turbines on the periphery of the area. This would minimise visual impact.

Section
Segment

Wind turbine lifetime

The lifetime of a wind turbine is generally expected to be 25 years. A decision must be made regarding the future of the wind farm toward the end of this period. The options would include the termination of production with subsequent demolition of the area and reconstruction of the wind farm. The relevant licensing requirements, in accordance with planning regulations and legislation on environmental impact, will be complied before any decision is made on the future of the Búrfell Wind Farm after it reaches the end of its lifetime.

Section
Segment

Búrfellslundur Wind Farm EIA report

The Búrfellslundur Wind Farm EIA report can be accessed here.
Further discussion on wind turbines is in chapter 3.1

EIA report

186 MB PDF