Fig. 2: AdaptiveHydro operation reduces system costs.
The AdaptiveHydro scheme reduces total system-wide cost and lowers the curtailment rate of VRE compared with FixedHydro. Such cost savings are driven by AdaptiveHydro and increase with decarbonization effort. a, Total system-wide costs over the entire planning horizon (2018–2050) under FixedHydro and AdaptiveHydro and the corresponding cost savings (yellow area) across different carbon emission reduction targets. b, Decomposition of total cost savings into six categories (that is, investment cost savings of coal-fired plant, investment cost savings of solar, investment cost savings of wind, investment cost savings of pumped storage hydropower, fuel cost savings of coal-fired plants and cost savings of operation and maintenance (O&M)) and how each category varies with the level of decarbonization. Negative cost savings indicate that the cost of a particular technology in the AdaptiveHydro scheme is greater than that of FixedHydro, as is the case with solar power. c, Curtailment reduction (yellow area) of VRE under AdaptiveHydro operation (pink line) compared with FixedHydro operation (blue line) across different decarbonization scenarios. d, Median (bold lines) and uncertainties (shading) of total cost savings under normal, dry (n = 8) and wet (n = 8) inflow conditions, as well as inflow conditions with interannual variability (n = 100) across different carbon emission reduction targets. The light and dark shading represent 95% and 50% confidence intervals, respectively.
