Role of GIS in Promoting a More Sustainable Future in Energy: A case study of theStädteregion Aachen in Germany
In the last decades, the world has experienced unprecedented population growth. Populations in the cities have doubled up with more than 74% of the country’s population live inside urban centres in developed countries. In developing countries, approximately 44% of the population are living in urban settings. With the influx of people in urban areas, there has been an increase in the consumption of energy. With increased use of fossil fuel, there has been constant pollution by gases like carbon dioxide, which has led to increased global warming and other associated pollution effects (Ramachandra and Shruthi, 2007). This paper seeks to employ GIS in planning and supporting renewable energy production and understanding the environmental impact associated with the production of with energy.
Methodological Framework
The methodological framework which is applied to this study can be summarized using figure 1 below. The key steps include, defining the criteria, assigning of value score, determination of exclusion areas, determination of rated are and deriving a suitable are for the location of wind energy source (Ramachandra and Shruthi, 2007).
Exclusion area
AHP Criteria
The next step is to undertake criteria to establish the suitability of the selected region. This criteria involve assigning value to every region and using those values as codes as the reference points. Every point is rated in accordance with the level of social acceptability. Those that are most accepted are given the first number and the number increases with the decrease in the social acceptability. By the use of ArcGIS, the distances between the criteria are calculated. The value cores are assigned to criteria using the reclassifying tools. By so doing, the assigned value score is numbered in accordance with its importance (Cowell, 2010). The resultant map will provide for weighted value scores for every study area.
The potential of wind energy
The speed and strength of wind is a key criterion in locating a wind turbine. It is the strength and the speed of wind, which determines the acceleration and hence the amount of Mega Watts produced by the turbine. Wind energy is therefore incorporated in every study and believed that is the most important criteria. Various areas with different strength of the wind are marked and then mapped. Areas which have an average speed of wind to be less than 6 meters per seconds are ruled to be uneconomical. Uneconomical in the sense that the amount of megawatts, which will be produced will not be commensurate with the amount of resources used to produce it. It is therefore important to mark and create value scores for every region with specific speed of wind. The value scores are then mapped using ArcGIS and used as a reference tool (Cowell, 2010).
Distance from road networks
Accessibility is also an important aspect in locating a wind turbine. Turbines constructed in area far from the road costs a lot in in constructing new roads. It is therefore imperative that wind farms be located in area closed to all weather roads. The roads must be tarmacked and should be at least 4 meters in width (Cowell, 2010). According to the German regulation, there should be a 2 meter gap between the road and the tip of the rotor blade connected to the wind turbine. In cases where the roads are state roads or district roads, the gap should be increased to 40 meters minimum. There is no set maximum distance between the road and the wind turbines; however, the nearer the roads, the less cost of constructing another access road.
Distance from electricity grids
For wind firm to be operational there has to be a constant supply of electricity. There is need to locate the wind firm in areas which have a close proximity electrical grid. This will reduce the cabling cost, hence reducing the average cost of constructing the firm. The location of a wind firm in relation to electric grid depends on the number of turbines. Where there are many turbines, there is a need to locate near the high voltage grid; while where there are few turbines, the medium voltage grid can work. There is no standard distance between the firm and electricity grid, however, numerous literatures have given an average of 200 m to be the maximum distance (Haaren, and Fthenakis, 2011). This means that the nearer to the grid the better in terms of cabling cost.
The Terrain of the land
The firm should be located in areas with gentle slopes. The threshold of the terrain should range from 10% to 40% (Haaren, and Fthenakis, 2011). Areas with steep terrains are quite inaccessible by the trailers and the construction bulldozers. This will in turn increase the cost of constructing the turbines. In regard to this study, a maximum threshold of 30% has been considered. This is what the topographical consultants agreed on, and this maximum will cover a large part of the area of study.
Distance from urban areas
Wind turbines produce a lot of noise which is quite disruptive to human existence. The German regulations have prevented the location of turbines near urban areas that will bring nuisance to urban dwellers. Therefore, in this case study, we excluded areas which were 550 meters away from residential are and 400 meters away from mixed use areas (Archer and Jacobson, 2016).
Distance from natural environment.
The German regulations stipulate that areas, which are allocated for preservation of birds and bats should be kept away from wind turbines. There should be a distance of at least 300 meters between the “no building zones” preserved for birds and bats and the location of the wind firm (Archer and Jacobson, 2016)
A survey was done to examine the relative importance of every criterion used for locating a wind firm. The results of the finding were tabulated as in the Table 2 below.
Using a concentration area map of the importance criterion, several locations were mapped and recorded as the most suitable areas for locating the air firms.
Conclusion
The use of renewable energy in Germany has been an important step towards cubing the environmental issues. With the increased levels of emission of greenhouse gasses and subsequently global warming, the government should opt for renewable energy such as wind. However, factors should be considered in locating the best site for constructing the wind firm. To ensure the stability of wind energy, these sites should be arranged according to their importance criterion and mapped for reference.
References
Höfer, T., Sunak, Y., Siddique, H. and Madlener, R., 2016. Wind farm siting using a spatial Analytic Hierarchy Process approach: A case study of the Städteregion Aachen. Applied Energy, 163, pp.222-243.
Archer, C.L. and Jacobson, M.Z., 2007. Spatial and temporal distributions of US winds and wind power at 80 m derived from measurements. Journal of Geophysical Research: Atmospheres, 108(D9).
Ramachandra, T.V. and Shruthi, B.V., 2007. Spatial mapping of renewable energy potential. Renewable and Sustainable Energy Reviews, 11(7), pp.1460-1480.
Ramachandra, T.V. and Shruthi, B.V., 2005. Wind energy potential mapping in Karnataka, India, using GIS. Energy Conversion and Management, 46(9), pp.1561-1578.
Van Haaren, R. and Fthenakis, V., 2011. GIS-based wind farm site selection using spatial multi-criteria analysis (SMCA): Evaluating the case for New York State. Renewable and Sustainable Energy Reviews, 15(7), pp.3332-3340.
Cowell, R., 2010. Wind power, landscape and strategic, spatial planning—the construction of ‘acceptable locations’ in Wales. Land Use Policy, 27(2), pp.222-232.
