Preliminary Site Selection of Pumped Storage Hydropower Plants - A GIS-based approach

The first stage in development and design of Pumped Storage Hydropower Plants (PSHP) is finding the optimum location. This paper presents a methodology for preliminary site selection of PSHP with the help of geospatial data analysis in a Geographic Information System (GIS) environment. The conventional method of PSHP site selection has certain limitations and is not cost and time effective. The volume of data and the criteria for the site selection of  PSHP causes a lot of difficulties for decision making. However, with the help of GIS as an information technology and with its analytical ability for decision making optimization, we can overcome these difficulties. Every criterion in a GIS can be illustrated as a separate data layer and site selection can be done according to the defined criteria. Overlay is one of the spatial functions that can combine spatial data layers from different sources for the site selection applications. In the process of site selection of suitable PSHP, various factors with different importance are considered.The Zayanderud pumped storage hydropower has been investigated as a case study. Suitable sites were identified based on spatial analysis in GIS environment. The Zayanderud PSHP is located in a dry and hot zone in central Iran and uses the existing Zayanderud dam lake as the lower reservoir. During this study, sites for upper reservoir location have been defined according to the artificial upper reservoir on the bank of the zayanderud reservoir. In this case study, at first, effective criteria for PSHP site location and corresponsive data layers have been defined. Then, data layers have been classified and prepared with respect to main criteria. Finally, results of overlay have been evaluated. The main factors used in PSHP  site selection process were; development pattern (using existing lake, rivers, sea, natural and artificial pools, etc. as upper or lower reservoirs), head, conveyance length-head ratio, slope, power grid situation, roads accessibility, geology and other technical points of view. The above mentioned factors were entered in GIS as data layers. Results of this investigation indicate that by using GIS, more suitable sites can be selected and verified and the feasibility study process can be done in more precise manner. This method can save more time and cost compared to the conventional approach.