Geographic Information System (GIS) mapping is playing a vital role in Worldwatch’s Low-Carbon Energy Roadmap project in the Dominican Republic. 3TIER – a company that performs renewable energy risk analysis and develops high-resolution mapping – has assisted Worldwatch by providing GIS data and maps for solar and wind resources in the Dominican Republic.
Generally speaking, GIS is a tool that can be used to integrate geographically referenced data. This computer-based system facilitates the collection, storage, manipulation, analysis, and display of information in a geographically organized manner. It is often employed to help visualize patterns, trends, and relationships amongst data and to compare the suitability of many locations for a specific project.
GIS mapping begins with a simple geographic map of a real-world location. Then, any number of datasets can be added to this baseline map, taking the form of additional map layers. Often, GIS maps are interactive. Users can change the amount of information they see in a map as well as zoom in and out.
Google Maps functions as a very simple example of a GIS map. By just going to the website and searching for a location, one is immediately provided with a plain geographic map. Within this simple map, one can then zoom in and out as well as manipulate the types of data that are visible, examples being terrain and current traffic conditions. If you have ever consulted Google Maps to make traveling plans, then you too have taken advantage of the services provided by GIS.
GIS mapping plays a critical role in the siting of renewable energy projects. Governmental, non-governmental, and commercial agencies routinely publish data sets describing the theoretical, technological, and economic potential of different renewable energies in specific locations throughout the world. GIS mapping allows policymakers, utilities, and planning commissions to directly compare these and other variables and to decide which locations make the most sense for renewable energy development.
GIS mapping is often used as a tool to reduce the social and environmental impact of renewable energy projects. By allowing spatial variables to be displayed beyond those that simply affect energy output, GIS maps enable project planners to avoid major project complications. For example, GIS maps have been used to map the migratory paths of the Black-Faced Spoonbill, allowing policymakers to avoid conflict with this endangered species when planning renewable energy projects in Taiwan. Often, patterns existing in data become much clearer when viewed through maps. So using GIS maps can highlight details that may have seemed unimportant when looking at them in a less organized fashion.
To date, 3TIER has assisted Worldwatch with its Low-Carbon Energy Roadmaps by providing GIS mapping for Dominican solar and wind resources. For its solar mapping, 3TIER collected solar irradiance, wind speed, and temperature data for the past 13+ years. Three types of solar irradiance – Global Horizontal Irradiance (GHI), Direct Normal Irradiance (DNI), and Diffuse Horizontal Irradiance (DHI) – were collected at half-hourly intervals at a high – 1 kilometer (km) resolution. Wind speeds were collected at a 4.5 km resolution for the past year and at a 13.5 km resolution for the past 13+ years. Using this data, 3TIER was able to create annual and monthly means for each variable and demonstrate how daily irradiation patterns vary throughout the year. Taking all of these factors into account enabled Worldwatch to draw conclusions about the overall strength of the Dominican Republic’s solar resources, and to identify sites with the strongest potential for developing solar projects.
In terms of wind, Worldwatch worked with 3TIER to assess wind resources for six zones in the Dominican Republic. To accomplish this, 3TIER divided each zone into 4.5 km x 4.5 km quadrants and used a mesoscale numerical weather prediction model (NWP), known as the Weather Research and Forecasting Model (WRF) (a description of the model can be found here). This model simulated the meteorology, most importantly the mean wind speed at 80 meters, over each quadrant for a 10-year period from January 1999 to December 2008. With this data, Worldwatch was able to identify the most suitable sites for wind energy development and provide this information to policymakers and project developers.
The siting of solar photovoltaic (PV) systems demonstrates why GIS mapping is important. Even though solar PV panels produce more electricity when they receive higher levels of solar radiation, this can come at a cost. Higher levels of solar radiation often translate into higher ambient temperatures. And because solar PV panels are typically black and absorb a lot of heat, PV panels located in hot areas can often heat up to well beyond 50 degrees Celsius. Problematically, solar PV cell efficiency drops by about 0.5 percent per 1 degree increase in temperature beyond the standard temperature of 25 degrees Celsius.
By displaying multiple datasets on one map, GIS mapping gives project planners the ability to compare solar radiation levels and ambient temperatures in specific locations, allowing them to construct solar power plants in optimal locations.
GIS mapping continues to play a critical role in renewable energy planning. The ability it gives project planners to identify optimal sites for renewable energy production as well as to alert project planners to probable future complications provides an invaluable service to the renewable energy industry.