Multi-objective optimization design of a grid-connected hybrid hydro-photovoltaic system considering power transmission capacity

The first step in creating a hybrid system that incorporates the adjustable hydropower station is selecting an appropriate scale of new energy. This study proposed a methodology for optimized design an on-grid hydro photovoltaic (PV) system considering power transmission capacity. The concepts of short-term joint hydro-PV operation were first given. The on-grid hybrid hydro-PV system's two evaluation indicators were then proposed, integrating double carbon targets and new energy power curtailments. Then, an optimization design model was established with maximum carbon emission reductions and minimum PV power curtailments. Finally, the methodologies were applied to a case study in northwest China to test its rationality. Results manifested that (1) PV power curtailments increase with carbon emission reductions under the given PV size and runoffs, and the optimized PV size was 200 MW; (2) the utilization rate of the newly add transmission channel generally decreases gradually with an increase in power transmission capacity expansion, and the optimum power transmission capacity expansion was 10 MW with the maximum utilization rate of 12.36%; (3) the hydro-PV joint production was impacted by both the characteristics of PV output and runoff. Thus, this study helps to the joint development of flexible hydropower stations and volatile new energy sources.