Fig. 3: Water sustainability value of VRE.
a, Annual hydropower production and water savings (scaled by circle size) versus VRE generation across all carbon emission reduction scenarios. The trend line (dashed line) was obtained by ordinary least-squares linear fitting between VRE generation and hydropower generation. b, Stacked area plot showing how the planned capacity of different technologies in 2050 varies with the degree of decarbonization. c, Variation of water savings with VRE generation and reservoir inflow. Each dot represents a combination of a carbon emission reduction scenario and an inflow scenario. Dots of the same colour represent one inflow scenario across all carbon emission reduction scenarios. The black dashed lines (from top to bottom) are linear fitting lines for scenarios with 40% wetter, normal and 40% drier inflow conditions. The black solid lines represent a certain carbon emission reduction scenario (that is, 20%, 60% and 100%). d, Uncertainties in the WSV across a dry inflow (brown line; n = 8), a wet inflow (green line; n = 8) and an inflow considering interannual variability (light-blue violin-shaped area; n = 100) for different ranges of decarbonization. The median values of WSV estimated from dry inflow, wet inflow and inflow with interannual variability are represented by brown dots, green dots and vertical blue lines, respectively. The black squares represent the WSV under normal inflow conditions. The brown and green triangles represent the values of WSV estimated from dry inflow and wet inflow used to derive statistics.
