Effect of floating photovoltaic system on water temperature of deep reservoir and assessment of its potential benefits, a case on Xiangjiaba Reservoir with hydropower station

Abstract

As green energy, the floating photovoltaic (FPV) system has many advantages. Taking Xiangjiaba reservoir as an example, a Ce-qual-W2 model was established to evaluate the potential impact of the FPV system on water temperature and its potential benefits. The result showed that: (1) FPV system could reduce the water temperature, water age, and relative water column stability of the reservoir; (2) the influence range of FPV on water temperature will not exceed 20% of reservoir length outside the coverage area in the flow direction. (3) FPV system would delay the reaching time of critical temperature threshold and accumulated temperature threshold for Coreius heterodon spawning, shorten the spawning period. The delay time of AT and CT under 100% coverage are 20.3 and 7 days respectively compared with no FPV condition; (4) FPV system can play a great role in power generation and emission reduction. Under 100% coverage, the power generation can reach 17.2 billion kW·h, reduce 14.4 million tons of carbon emissions and save 35.12 million m3 of water. This study can provide a reference for the impact assessment of the FPV project on the water environment and the formulation of the FPV coverage scheme.