SPPSouthwest Power Pool

Jul 28, 2026

Solar curtailed

1.3 GWh

Wind curtailed

3.2 GWh

Solar · 30d34.5 GWh

Wind · 30d392.8 GWh

90-day trend

SolarWind

SPP · kardashev-data

CAISOCalifornia

Jul 27, 2026

Solar curtailed

9.9 GWh

Wind curtailed

129 MWh

Solar · 30d226.3 GWh

Wind · 30d15.2 GWh

90-day trend

SolarWind

CAISO · kardashev-data

The duck curve: midday solar dips net load, evening demand peaks

What is curtailment?

When the grid can't absorb all available solar and wind, operators instruct generators to produce less, even when the sun is shining. High curtailment signals congested transmission, insufficient storage, or poor demand timing.

CAISO leads in solar curtailment (the duck curve). SPP leads in wind curtailment across the Great Plains.

Wind turbines on the Great Plains at dusk

Open source

kardashev-data API · Next.js. CAISO + SPP live. Fork it, add yours.

View on GitHub↗

Curtailment by ISO

What is curtailment?

Open source