High-Elevation Hydropower and Climate Warming in California

In California Climate warming is expected to shift the runoff peak from spring to winter from a reduction in snowpack. For high-elevation hydropower plants, this shift can have important effects on power generation and its economic value. With over 150 hydropower plants in California, estimation of climate warming effects by conventional simulation or optimization would be tedious and expensive. Two approaches are suggested to estimate climate warming effects on high-elevation hydropower in California. The first (No-Storage) approach neglects available storage capacity and produces an upper bound estimate of lost generation and hydropower revenues from climate warming. The second (No-Spill) approach estimates the available energy storage capacity assuming that existing capacity is enough to avoid spill from high-elevation reservoirs with historical mean flows, providing a lower bound estimate of generation and economic losses. The generation changes in dry and wet climate warming scenarios at different elevation ranges are simulated in aggregate for several climate change scenarios and compared to the historic generation.