Welcome to Mark Xu’s exploratory tool for identifying potential sites suitable for wind farms

This tool is intended for a generalized evaluation of potential wind farm sites at a regional scale, and is currently only developed for the Wanganui region. This tool allows the user to choose their own sets of criteria from a total of 3645 sets of criteria. Users can therefore explore the trade-off that different criterion have on the number and extent of sites suitable for wind farms.

To use this tool simply select the criteria from the pull down menus below and click “GO”. A selection for each criterion must be made. If a criterion is not reqired then select “Not Considered”.

For more details on criteria read the descriptions below.

Please select the criteria parameters

Urban visual impact:

Distance from power lines:

Distance from road:

Mean wind speed:

Relative elevation:

Mean slope:

Minimum area criteria:

Indigenous vegetation: excludes areas that covered in indigenous vegetation.

Land use conflict: excludes areas that are within 500 m of important archaeology sites and military sites.   

Descriptions:

Urban visual impact:
The urban visual impact criteria determine the potential visual impact of wind farms on urban areas. The view from urban areas is analysed by converting an urban area layer into grids of points. Each point is used as an observation point for visibility analysis. Two thresholds are available. The first is that no urban area is visible, and the second is that less than 40 hectares of urban land is visible from a potential wind farm site.

Distance from power lines:
The distance from power lines criteria were used to determine the accessibility of the national power grid to a potential wind farm site. This is based on Euclidian distance. Two distance criteria are available - within 5 km and within 10 km.

Distance from road:
The distance from roads criteria is similar to the distance from power lines criteria. It is based on Euclidian distance and determines the accessibility of a potential wind farm site to the road network. Two distance criteria are available - within 5 km and within 10 km.

Mean wind speed:
The mean wind speed criteria determine areas that have suitable mean wind speeds for wind farm development. Two wind speed ranges are available - 10-25 m/s and 10-30 m/s.

Relative elevation:
The relative elevation criteria identify areas that are positioned on ground that is higher relative to the surrounding area. This is calculated using a digital elevation model and the elevation range within a 500m search radius. The elevation of a site is divided by the elevation range and the resulting percentage provides an indication of the relative elevation. The higher the percentage for a site the higher its relative elevation. A mountain top will have a 100% while a valley floor will have 0% relative elevation. Two thresholds are available - above 50% and above 75%.

Mean slope:
The mean slope criteria determine areas that are relatively flat. This is based on the mean slope within a 500m radius. Two mean slope thresholds are available - less than 10 degrees and less than 15 degrees.

Minimum area criteria:
A viable wind farm requires a minimum area size to ensure economies of scale. Two approaches to calculating area are used. The first is based on the size of clustered patches. In this situation there may be many small areas in close proximity that in total provide a viable economic size. The total area was calculated by summing the area of suitable sites within 400 hectares (based on a 200m by 200m search neighbourhood). The second approach uses contiguous area and calculates the total area of potential sites that are connected. Two thresholds are available for clustered patches – more than 100 ha and more than 200 hectares, and two thresholds are available for contiguous patches – more than 200 ha and more than 400 hectares.

Indigenous vegetation:
Areas of indigenous vegetation are automatically excluded as potential wind farm sites. Information on indigenous vegetation is based on areas identified as indigenous forest or scrub in the Landcover 2 database.

Land use conflict:
Sites of potential land use conflict are automatically excluded as potential wind farm sites. These sites include important archaeological sites identified from the NZ archaeological database. A 500m buffer around those sites was used.