A GIS-based assessment of Tibet's potential for pumped hydropower energy storage

The cost reduction of photovoltaic (PV) module makes solar energy a promising renewable energy for large-scale electricity generation, further controlling the green house gas emissions. A primary obstacle for the connection of PV generation into electric grid is its poor stability, due to the variation of solar radiation, which determines the PV output. Pumped hydroelectric storage (PHS) is an efficient energy storage method to stabilize the intermittent PV output. Tibet, where solar radiation is in abundance, presents an opportunity to install PV stations across China, and unified construction of PHS is necessary for grid-connected utilization of the solar energy there. The objectives of this study are to evaluate the PHS potential in Tibet and to provide promising locations of the PHS stations, through Geographic Information Science (GIS) analyses. A review of the existing GIS methods (T1-T7) for PHS site selection was firstly given. Two new GIS models (S1 and S2) appropriate for Tibetan area were proposed then, and the T1, S1 and S2 were considered for this assessment. Results showed that the total PHS potential in Tibet was about 997.2 GW h, 946.2 GW h and 2552.0 GW h under T1, S1 and S2, respectively. All the promising sites were mapped, and an assessment of these sites were made according to their distances to grid connections. The results were supposed to benefit the planning of the PHS facilities in Tibet.