SPP · Southwest Power Pool
The regional grid operator spanning the central US plains, a market regime with its own study sequence, cost allocation, and curtailment obligations.
Current numbers
Maximum 7-year conditional non-firm termSPP CHILLS conditional service term, not a study duration
0.90–1.10 pu continuous; 0.15 s below 0.50 puSPP HILL ride-through (2025-09-23): 0.80–0.90 pu 2.00 s; 0.50–0.80 pu 0.50 s; under 0.50 pu 0.15 s; upper ends exclusive
18 / 15 / 10 GWcurtailment-enabled headroom at 0.5% in PJM / MISO / ERCOT (SPP also ~10 GW; Southern ~8 GW)