Wind turbine location suitability

Introduction

With the growing expansion of the city, Ottawa energy capacity requirements have become an important issue. Energy Ottawa currently supplies a majority of its energy to the city through what is known as the ‘run-of-the-river’ generating system. This is a series of small scale hydroelectric dam facilities spread out across the region's watershed (Energy Ottawa, 2010).

This method of energy generation is considered a green means of producing energy, as it does not typically involve emitting pollution into the atmosphere when compared to coal, petroleum, or natural gas. What is often overlooked is the negative affects that hydroelectric dams pose to the health of a watershed, impacting many aspects of both the natural and social environment. These adverse affects have caused the number of hydroelectric dams being built to be drastically reduced in Canada (Natural Resources Canada [NRC], 2009).

This has led many municipal and provincial governments to seek alternative green energy production techniques. Wind energy has come to the forefront of this search. Wind energy is, however, not without its negative implications as well. Recent studies have been produced which link the construction of wind farms to the degradation the environment in sensitive areas, as well as possibly having negative implications for human health due to prolonged exposure in close proximity to wind turbines. To mediate these concerns, the Government of Ontario has imposed various restrictions, limiting areas in which the construction of wind farms is permitted.

Objective

The objective of this tutorial is to demonstrate a technique which identifies spatial regions deemed as potentially suitable locations for the development of wind energy production. In evaluating regions where wind turbine projects have been proposed, the technique will take into consideration the restrictions imposed by the provincial government on wind turbine locations. The desire in this particular case is to identify suitable locations for wind energy production in Ward 21 of the Ottawa, Ontario region.

Restrictions

The Government of Ontario has provided the following restrictions in relation to the spatial placement of wind energy turbines for use in commercial applications:

• 135 m from all existing public roadways

• 135 m from all existing railway lines

• 1000 m from all existing transmission lines

*These restrictions are relative to the turbine specifications of the Vestas V90, 3 megawatt model

These restrictions were provided by:

• Renewable Energy Approvals
• Technical Bulletin Six: Required Setbacks for Wind Turbines
• Drafted by the Environmental Registry March 1, 2010

In addition, in 2016, the Ontario government provided a location and site considerations checklist for alternative energy projects, including wind turbines. It covered noise and odour, ecological, and infrastructure site considerations. In terms of ecological considerations, site selection had to consider impacts on significant wildlife habitats, wildlife corridors, known provincially significant wetlands, significant woodlands. provincially significant areas of natural and scientific interest, water bodies (lakes, streams, seepage areas) and provincial parks or conservation reserves. Specific limitations on site selection included:

• 30-120 m from water bodies
• 50-120 m from significant natural heritage features (woodlands, wildlife habitat, wetlands, etc.)

Methods

The following will thoroughly demonstrate the techniques involved in an approach for identifying suitable wind energy production sites in the Ottawa city area. This example looks specifically at Ward 21, Rideau-Goulbourn.

Data Used

The first step is to gather all necessary data appropriate for the purpose of this exercise. This example uses vector shapefiles which include:

• Ottawa city wards boundary - City of Ottawa "Wards" data set from Open Ottawa: https://open.ottawa.ca/datasets/wards
• Transmission lines - "Transmission Lines line" data set from DMTI Spatial Inc.: http://geo.scholarsportal.info/#r/details/_uri@=3726223876
• Railways - City of Ottawa "Railway Lines" data set from Open Ottawa: https://open.ottawa.ca/datasets/railway-lines
• Roads - City of Ottawa "Road Centrelines" data set from Open Ottawa: https://open.ottawa.ca/datasets/road-centrelines
• Water - City of Ottawa "Water" data set from Open Ottawa: https://open.ottawa.ca/datasets/water
• Wooded areas - Wooded area data set from the Ontario Ministry of Natural Resources: http://geo.scholarsportal.info/#r/details/_uri@=1335213247

These data can be gathered at https://open.ottawa.ca/ or at http://geo1.scholarsportal.info/

Software Used

The exercises demonstrated are completed using the Quantum GIS 3.8.1 Zanzibar software interface. These are open source software materials which are freely accessible and available online. For new users it is suggested to use the standalone installer.

This is available by clicking this hyperlink. Click this!

Starting Map Project

Before beginning it is recommended that you make sure that all shapefiles you will use have sensible and descriptive names, to make sure that you do not get confused. Do the following pre-processing steps to prepare your data:

1. Begin by opening the Quantum GIS software. Select ‘Layer’ from the drop down menu and open the ‘add vector layer’ function or click the ‘add vector layer’ icon on the toolbar. Ensure source type is set to ‘file’. Locate vector dataset by selecting ‘browse’ and open a shapfile which will be used for the project. Click ‘open’ and the shapefile will be added and displayed. Repeat this process until all shapefiles intended for use have been added.
2. Once all vectors have been added, you should set the coordinate reference system (CRS). The best way to do this is to re-save each layer with the desired projection. This can be accomplished by selecting the layer and then selecting the "Save as" option from the Layer drop-down menu located at the top. Select "ESRI Shapefile" from the "Format" dropdown menu, enter the filename, and then select the desired projection through the CRS drop down menu. The recommended CRS is WGS84/UTM Zone 18N EPSG 32618. Press okay.

1. Next the vector files must be clipped to fit within the extent of the Ottawa area. If all your data fit within the boundaries of Ottawa, skip this step.
   1. Select the 'Vector' tab at the top, the 'Geoprocessing' menu and select the Clip tool.
   2. In the 'Input layer' section select the layers that need to be clipped down. Do this individually for each layer that needs to be clipped.
   3. In the 'Clip layer' section select the layer that will act as your extent, the Wards layer.
   4. The next section is for specifying your output. Click the 3-dot button and and select save to file. Name your new file with details (example: TransmissionLinesUTMClipped), and save click save in that new window.
   5. Make sure the box under the output section is checked to allow the program to automatically add it to your working layers.
2. If the clipping tool has a blank output and you get a warning message that the CRS do not align and will cause problems, this is the solution to that problem (skip if the clipping worked):
   1. Click the CRS button on the bottom toolbar of the program, beside the speech bubble. At the top of that popup, you want to enable the 'On the fly' transformation, if it is not enabled already.
   2. From here, select the layer in the Layers Panel that is not aligning with your desired CRS, and right click it. From this menu select the 'save as' option and create the same shapefile with a new name, and with the CRS of the project. This creates the shapefile again, but this time with the CRS aligning with the project, and allowing you to work with the layers using geoprocessing tools.
3. If your layer has a geometry error that prevents clipping (the Water and Wooden Area layer has this problem), the solution to this problem is to create a buffer for the layer with a value of zero. This can be accomplished by selecting the "Vector" from the top menu, the "Geoprocessing" tools from the drop down menu, and then selecting "Buffer". For the input layer, select the layer with the geometry problem that needs to be buffered, and set the Distance at 0 metres. Under "Buffered", click the 3-dot button and and select save to file. Name your new file with details (example: WaterZeroBuffer) and click "Run" in that new window. The buffered layer should then appear in your layer list. It should be renamed accordingly by right clicking on the layer, selecting properties, selecting "source" from the side menu, and changing the layer name in the "Layer Name" box.

Narrowing Results to a Specific Delineation Area

This section focuses on narrowing the view to a specific area of interest. In this case the area of interest is Ward 21, Rideau-Goulbourn. This is a largely rural/agricultural ward of the city, making it a prospective optimal area for the production of wind energy. This process will involve the exporting of the specified area as a new shapefile.

1. The following steps demonstrate the exportation of a specific area of interest as a new shapefile:
   1. Right click the "Wards" layer in the layer panel, and select the " Attribute Table".
   2. Next, select the ward you want to create a new shapefile out of, this time being ward 21.
   3. Close the attribute table and then select the "Save as" option from the Layer drop-down menu located at the top. Select "ESRI Shapefile" from the "Format" dropdown menu, enter the filename, and then check the projection through the CRS drop down menu. The recommended CRS is WGS84/UTM Zone 18N EPSG 32618. Under "Encoding", check-off "Save only selected features" Press okay.
   4. Add the newly created shapefile to the map project if not already present.
2. With the new ward extent shapefile, you want to trim the extra data down to fit within it.
   1. It is similar to the clipping tool, but this time select the 'Intersection' tool.
   2. Input the data you want to cut down and show them instead of the full extent shapefiles.

Visualization of Restrictions using a Buffer

This section will demonstrate how to add a buffer region to each of the vector layers representing the limitations imposed by the spatial restrictions set by the Government of Ontario.

1. Open the "Vector" tab and go to the "Geoprocessing" menu, and select the "Buffer" tool
2. To create the railway buffer, select the Railway Lines layer under the 'Input layer' field
   1. Set the 'Distance' field to 135 (this number represents the 135m restriction applied to Railways)
   2. Leave 'Segment' as the default 5, as changing this does not have a significant impact on the end result.
   3. Make sure the dissolve box is checked, which makes the buffer a continuous shape, instead of separate entities.
   4. Click the 3-dot button and and select save to file, name your new file with details (example: RailwayLinesUTMClippedBuffer135m), and click save in that new window.
   5. Click Run, and wait for the output to successfully finish (this may take an extended period of time depending on the size of the input vector layer
3. 
4. Complete this process for Road Layers, again setting the 'Distance' to 135 as the restriction for roads is the same as railways.
5. When completing this process for the Transmission Lines layer, make sure to change the 'Distance' parameter to 1000 to meet the 1000m restriction imposed on this infrastructure.
6. For both "Water" and "Wooded Area", make sure to change the "Distance" parameter to 120 metres to meet the 120 m restriction imposed on these areas.

Representation of the Resulting Layers:

Creation of Total Suitable Areas Using an Overlay

This section will demonstrate the use of vector overlay techniques in order to visualize the suitable areas for wind turbines that are free of spatial restrictions.

Using Union to Create a Merged Buffer Layer

1. Select the 'Vector' tab, select 'Geoprocessing tools' and select 'Union' as the last part of the menu.
   1. Under the 'input layer' field choose the Railway Buffer layer.
   2. Under the 'input layer 2' field choose the Transmission Lines Buffer layer.
   3. Under the 'Union' field provide an output name (example: RailwayTransmissionLinesUnion)
   4. Click run, and wait for the output to successfully finish.
2. Return to the 'Union' tool.
   1. Under the 'Input layer' field choose the Union layer just created (example: RailwayTransmissionLinesUnion).
   2. Under the 'Input layer 2' field choose the Roads Buffer layer.
   3. Under the 'Union' field provide an output name (example: RailwayTransmissionLinesRoadsUnion)
   4. Click run, and wait for the output to successfully finish.
   5. Repeat the same process for Water and Wooded Area to add these two buffered areas to the "Union" layer thus creating two more union layers (RailwayTransmissionLinesRoadsWaterUnion and RailwayTransmissionLinesRoadsWaterWoodedAreaUnion). The latter layer is the final merge layer incorporating all five buffers.

Using Dissolve to Clean Up the Final Merged Buffer Layer

1. Return to the 'Geoprocessing tools' tab and select the tool 'Dissolve'. This will clean up the merged layers.
   1. Select the shapefile you just created as the final merge, and check the box 'Dissolve All'.

This process results in the overlay of all five buffer restriction layers providing a total suitability layer which considers all restrictions.

Representation of the Resulting Layer:

Identifying Largest Suitable Area

The Largest suitable area can be identified using the 'measurement tool' located on the toolbar. However, this would take a lot of time to outline each shape, so I will show you a way to calculate each area.

1. The first step is to go 'Vector'>'Geoprocessing'> 'Difference'.
   1. Select the extent area as the input and the merged buffers as the difference.
2. You now can see each individual shape away from the buffers, which allows us to calculate the area of each shape.
   1. First we must separate them in the attribute table, and to do this we must create another shapefile. To do this go 'Vector'>'Geometry'> 'Multiparts to Singleparts'.
   2. Select the created shapefile from the 'Difference' tool and create a new shapefile of separated features.
3. Now turn on editing of this new shapefile, and open the attribute table to reveal the large number of features present in this shapefile.
   1. You can turn on editing by right-clicking the layer in the Layer Panel and selecting the 'Toggle Editing' option.
   2. Once in the attribute table create a new field. You will want to name the field "area" and select 'Decimal Number'. Precision and Length can be left default.
   3. Now open the 'Field Calculator' and select 'Update existing field' and select the field you created.
   4. In the search bar below, type in "area" and select the option named "$area"
   5. press 'OK' and all shapes will have an updated area field in meters squared. Sort the new field to find the largest in terms of area.
4. Once the largest suitable area has been identified, create a new vector polygon to represent this area. This can be done with the same process that was used to create the Ward 21 polygon from the Wards layer.

Representation of the Resulting Layer:

The resulting layer provides the largest suitable area for the specific region of interest with the consideration of all implied restrictions. By combining all the final layers together, you would get a map that shows the most suitable locations for wind turbines, along with the provincial restrictions set in place. This process can be used for any of the wards in the Ottawa region, and it could be used to select different areas with different restrictions, all depending on the data present.

Final output map

References

• Energy Ottawa. (2010). "Green Power". Accessed online: http://www.energyottawa.com/forms/index.cfm?dsp=template&act=view3&template_id=46&lang=e
• Ministry of the Environment, Conservation and Parks. "Location/site considerations checklist for renewable energy projects" Accessed online: https://www.ontario.ca/page/locationsite-considerations-checklist-renewable-energy-projects
• Natural Resources Canada. (2009). “Hydroelectric Generation”. The Atlas of Canada. Accessed online:http://atlas.nrcan.gc.ca/auth/english/maps/freshwater/consumption/hydroelectric/1