Theories and methodology of complementary hydro/photovoltaic operation: Applications to short-term scheduling

The recently implemented Longyangxia 320 MW complementary hydro/photovoltaic (PV) project provides a novel operation mode for utility-scale PV power plants. In this paper, the principle of complimentary hydro/PV operation is presented. In short-term scheduling, hydropower can improve the power quality of PV by compensating for the sawtooth-shaped power output curve of PV and for the intermittent and random output of PV. Conversely, in mid- to long-term scheduling and during peak load regulation, PV can compensate the hydro energy deficiency of hydropower via the electricity generated. The concept of virtual hydropower is also proposed. The ability of hydropower to compensate for PV is analyzed, and curtailment situations for solar energy and water as well as their causes are detected. Finally, a calculation model for complementary hydro/PV operation is developed based on the Longyangxia project. The results show that complementary hydro/PV operation can remarkably improve the power quality of PV and is better able to reduce the peak load than a standalone hydropower plant. (C) 2015 AIP Publishing LLC.