ArcNews Online

Fall 2009

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GIS to Meet Renewable Energy Goals

Throughout the developed world, there is ongoing interest in renewable energy as a replacement for traditional fossil fuel. Wind farms are cropping up around the world, and the sunniest spots are slated for solar power potential, while additional significant strides are being made to expand geothermal, tidal, biomass, and other types of generation. Motives for renewable energy development vary from place to place, but the recurring theme is a reduction in greenhouse gas emissions—a smaller carbon footprint. All agree on the need to tread more lightly, and with GIS technology, the path to renewable energy is becoming clearer.

  example of vento ludens web site
vento ludens: Protected areas and minimum distances combine in one map to display suitable areas in white.

The identification of areas technically suitable for renewable generation involves the collection of existing information, such as historical wind speed and direction, terrain and slope information, and solar radiation. Data must be analyzed for currency, accuracy, and completeness. Further data collection may be required.

Once base data is available, specific generation requirements can be modeled and applied against that base data. With wind generation, wind speed and duration must be sufficient for turbines to work properly. Similarly, for concentrated solar, sun intensity and the number of sunny days dictate the suitability of an area. Applying the technical models against the base data will classify sites that are technically suitable.

As with analysis for technical suitability, a similar analysis is conducted using data that identifies lands of limited or highly undesirable usability. Typically these are lands of cultural importance, such as historical Native American tribal lands, national parks, or other areas of scenic beauty. The area may be a protected animal habitat or migration zone. The result of this analysis indicates geographic areas that represent few or no barriers to renewable generation development.

Merging the datasets from the first two types of analysis will demonstrate where generation facilities could be constructed with confidence that the site is technically appropriate and where there would be no social objections to their presence.

The last step is to consider the proximity to a transmission grid to deliver power into the grid. It would be unusual to find that no transmission lines are required; the goal is to find sites that minimize this construction requirement.

Utilities, governments, and organizations around the world are using ArcGIS technology for renewable energy development. The following examples describe some of these organizations and highlight some of their methods and successes.

vento ludens—Searching for Suitable Sites

The name of German-based renewable energy developer and investor vento ludens GmbH and Co. KG is Latin for "he who plays with the wind." But, vento ludens does much more than play. The company is actively pursuing suitable sites for the production of clean, renewable energy in Germany, Switzerland, Scotland, and the United States.

"The procedure for finding sites for wind farms and solar power plants is basically the same; the only difference is the data used," says Simone Blaga, project manager, vento ludens. "The perfect site for a renewable energy installation needs to fulfill certain conditions. Information, such as land survey data, is evaluated by specific ArcGIS Desktop applications in order to make a site evaluation."

Once an area is determined to have sufficient renewable resources, engineers at vento ludens must determine the most suitable precise location for a production facility. Regional guidelines, for example, prohibit placement of wind turbines in protected wildlife areas. It is also important to maintain prescribed distances from streets and other transportation routes.

With shapefiles of such criteria, vento ludens is able to rule out restricted land by creating buffer zones on its maps using ArcGIS Desktop. Each shapefile is added as a separate layer. All layers of excluded land are then positioned on top of each other to reveal all off-limits terrain. Engineers then activate the layers that show renewable resource potential, such as high wind speed. When the usable land coincides with resource potential, the area is considered a viable site.

Engineers then use ArcGIS 3D Analyst and the extension's ArcScene application to create a 3D model for visibility analysis. The visibility of new sites should be as unobtrusive as possible and with minimal impact on the landscape. A digital terrain model includes the x- and y-coordinates, as well as all geodetic points. For the public, authorities, and landowners involved in a project, this analysis can be very helpful because it reveals how the installation will look and how it will be integrated into the surrounding area.

"GIS makes the site evaluation process a lot easier and helps us continue building new wind farms and solar power plants," says Blaga. "In doing so, we are making a contribution to ensuring a naturally sound and secure worldwide energy supply."

For more information, contact Simone Blaga, project manager, vento ludens GmbH and Co. KG (e-mail:

Solar Boston—Determining Resource Potential

  example of Solar Boston web site map
Users can browse active solar installations throughout Boston.

Through a program known as Solar Boston, the Massachusetts city is using Web GIS technology to map current solar installations and allow Bostonians to analyze their rooftop solar energy potential. Solar Boston's Web application helps the people of Boston easily start learning about the feasibility of solar projects.

To promote the use of solar energy to investors, the Boston Redevelopment Authority (BRA) needed a system to showcase research and analysis in a user-friendly format. GIS was the obvious tool to achieve this end because it started with a visual reference—a map of the entire city showing the buildings that had solar installation potential.

"We needed a baseline, because you can't really get anywhere if you don't know where you are," says Wilson Rickerson, Solar Boston coordinator. "Without GIS, we'd have no concept of the size of the city's solar industry, how fast it had grown, and what potential it had."

GIS analysts at BRA started on the project by using ArcGIS Desktop software's ArcGIS Spatial Analyst extension to calculate the solar radiation available on building rooftops. To do this, they built a digital elevation model (DEM) of the city.

"We took the bare earth DEM and ‘burned' into that the building heights using attributes available in the building footprints, which resulted in a three-dimensional surface model of the city," says Greg Knight, senior GIS applications developer with BRA. "We proceeded with this prepared surface and utilized the solar radiation tools available in the GIS to calculate what the solar radiation availability would be for each rooftop."

The solar radiation tools allowed analysts to model incoming solar radiation and take into account numerous factors, including variation in elevation, orientation (slope and aspect), the shadows cast by topographic features, and changes with time of day or year. After completing the analysis in ArcGIS Desktop, the solar radiation map was published, along with a basemap, other layers of interest (e.g., historic and local electric utility districts), an address locator, and geoprocessing tools, to ArcGIS Server for use by the Solar Boston Web application.

Wrapping the analytics in an easy-to-use Web GIS application was the next step. GIS developers at BRA saw great potential in Esri's new ArcGIS API for Flex, which is a client-side technology rendered by Flash Player 9 or Adobe AIR. Flex gives developers the capability to combine GIS-based Web services from ArcGIS Server with other Web content and display it in a fast, visually rich mapping application that can be deployed over the Web or to the desktop. It was the ideal medium to show investors the logistics of solar energy investment.

For more information, contact Greg Knight, senior GIS applications developer, Boston Redevelopment Authority (e-mail: See Solar Boston's Web GIS in action at

Kyushu University—Airflow Analysis for Wind Power

  a model of a baseball stadium in Japan
Kyushu University: A model of a baseball stadium in Japan, showing the airflow around the stadium. This was created with ArcView, ArcGIS 3D Analyst, and Airflow Analyst.

To harness the power of the wind, one must first study the wind's movement. Takanori Uchida, a professor at the Kyushu University Research Institute for Applied Mechanics in Japan, understands this notion. Uchida works with computational fluid dynamics (CFD) technology and GIS to study and predict wind flow.

Wind flow through an urban landscape can help determine the potential for rooftop windmills. An energy engineer can assess not only the best roof but the best location on the roof to place wind generators, as well as predict what the energy output of the generator might be, given certain conditions.

Energy companies can apply CFD to siting transmission assets or assessing how wind will flow around certain complex shapes, such as various types of power generators. Users may choose to determine a landscape's active wind corridors and combine other information, such as environmental considerations and land titles, to assess the value of a wind farm site.

Uchida and his team have developed a new ArcGIS Desktop extension, Airflow Analyst for ArcGIS, that makes it easier for people to process wind energy data in a GIS environment, turning wind assessment into more practical applications. The extension can model data; perform complex calculations; and generate visualizations in 2D, 3D, animated, and temporal representations. With this extension, researchers can more easily perform risk management wind analysis, such as forecasting diffusion of smoke, noxious gases, and other toxic pollutants.

For more information, contact Environmental GIS Laboratory Co. Ltd (e-mail: or Takanori Uchida (e-mail:

Cascade County—Attracting Renewable Investors

  photo of Horseshoe Bend Wind Farm
Horseshoe Bend Wind Farm in Cascade County, Montana (source: John Godwin).

In the U.S. state of Montana, along the eastern slope of the Rocky Mountains, sits Cascade County, a region known for its powerful Chinook winds. Cascade County Commissioner Peggy Beltrone, who also serves on the U.S. Department of Energy's Wind Powering America steering committee, is leading a wind marketing program for the county that is receiving attention around the globe.

"The way to differentiate the wind that crosses through your county and the next county is to draw attention to it and make it easier for developers to explore your wind resource and see its value," Beltrone says.

Cascade County is using GIS to help wind power developers research available parcels. In addition to attention from regional developers, interest has come from businesspeople as far away as Japan and Ireland.

"We have a lot of people coming into our office looking for data on wind," says Tom Mital, GIS manager for Cascade County. To better serve these interested parties, Mital used ArcGIS Desktop software to create a wind map book that combines wind, transmission, parcel, and road data. The wind speed estimates for an elevation of 50 meters above the ground were produced by TrueWind Solutions using its Mesomap system and historical weather data. The data was then validated with surface data from the National Renewable Energy Laboratory and wind energy meteorological consultants.

A PDF version of the map book is available on the GIS Department Web page of the county Web site at On that Web page, there are also links to a wind power map and wind speed map that visitors can download in PDF format. If someone would like more detail about a specific area, Mital will create a custom map.

"The advantage of using GIS in the marketing of your wind is that it gives developers a lot of information that they need to decide whether or not placing a wind turbine in this area is going to work for their power needs and their budgets," Beltrone says. "One executive told me that the information we provided saved his staff months of work since we did all the work for them. If he can take a look at our resources without having to invest time and money into preliminary research, it's a big draw."

For more information, contact commissioner Peggy Beltrone (e-mail:, Web:

BirkNielsen Sweco Architects—Environmental Impact Assessment

  map showing the visibility of proposed wind turbines
BirkNielsen: The visibility of proposed wind turbines is displayed. From the white areas, you will not be able to see the wind turbines.

Dotting the landscape with wind turbines can adversely affect the environment and cause the community to take umbrage. To ward off such risks, developers enlist the help of people such as Christian Achermann, an urban designer from BirkNielsen Sweco Architects A/S in Denmark, to create an environmental impact assessment (EIA).

"An environmental impact assessment," Achermann says, "should identify, describe, and assess the direct and indirect effect on humans, fauna, flora, soil, water, air, climate, landscape, material assets, cultural heritage, and the interaction between those elements."

For projects with large wind turbines, Achermann says it is especially important to investigate the visual and landscape impact. A visual analysis addresses issues surrounding wind turbine design, size, style, and patterns from a landscape architecture perspective.

For example, when a private builder wants to install wind turbines at a specific site, local politicians and community members need more information to handle the request. They need to know which transportation routes will be traveled by trucks accessing the site, how the site will be restored when or if the turbines are no longer useful, and what changes the area will undergo on account of the wind power facility. An EIA gives them something concrete to discuss.

"If you do not have a fairly accurate picture of how it will look, it becomes pure guesswork," Achermann says. "We use GIS to translate guesswork into something quite specific, and on this basis we can make an assessment as landscape architects."

Achermann and his team use ArcGIS software to create thematic maps with up to 30 layers of relevant data. The maps are shared with interested parties online. The use of GIS-based maps allows politicians and the community at large to understand and visualize the ramifications of a nearby wind facility.

For more information, contact Christian Achermann, urban designer, BirkNielsen Sweco Architects A/S (e-mail:

U.S. National Renewable Energy Laboratory—Economic and Government Considerations

  South Dakota's wind resource map
NREL: South Dakota's wind resource map depicts an outstanding resource. Transmission lines with voltages can also be seen on this map.

The U.S. National Renewable Energy Laboratory (NREL) recently took on the task of updating wind resource maps to educate government decision makers and developers interested in regional renewable energy.

Using ArcGIS Desktop software, the NREL team is able to determine the most favorable locations for wind farms based on the cost of transmission, locations of load centers and wind resources, and the layout of the electric grid. GIS-based modeling enables analysis of terrain, which significantly impacts the quality of wind at a particular site.

The NREL team also examines economic development potential based on strong manufacturing centers and filters the data to exclude sites such as national parks and wilderness areas.

For utility developers, NREL creates forecasting models. Maps include details such as voltage of transmission lines and classes of wind speed and wind power. Forecasts include projected wind capacity by state in 2030 and the expansion of transmission lines that would be required.

For more information, contact Marguerite Kelly, senior project manager, NREL (e-mail:

Renewable Generation Location Summary

As shown in the above examples, the identification of a renewable generation location consists of several common steps: Locate geographic areas that are suitable from a purely technical consideration. Name any factors that would prohibit construction, such as environmentally or culturally sensitive lands. Take into account proximity to the transmission grid to avoid the need for new lines. To make these processes most efficient, GIS can collect and view each group of data for consideration.

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