Curtailment by ISO
SPPSouthwest Power Pool
Sep 19, 2026Solar curtailed
660 MWh
Wind curtailed
27.2 GWh
Solar · 30d27.7 GWh
Wind · 30d424.3 GWh
90-day trend
SolarWind
SPP · kardashev-data
CAISOCalifornia
Sep 18, 2026Solar curtailed
18.0 GWh
Wind curtailed
315 MWh
Solar · 30d141.2 GWh
Wind · 30d3.4 GWh
90-day trend
SolarWind
CAISO · kardashev-data
What is Published Curtailment?
When the grid can't absorb all available solar and wind, operators instruct generators to produce less, even when the sun is shining. These pages show Published Curtailment at the ISO/fuel grain the ISO already publishes. Negative prices are Markets stress, not curtailment.
CAISO leads in solar curtailment (the duck curve). SPP leads in wind curtailment across the Great Plains.
