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
~0.50 pu, ~0.15 sSPP demand-facility ride-through floor (0.90-1.10 pu continuous; short excursions to ~0.5 pu)
18 / 15 / 10 GWcurtailment-enabled headroom at 0.5% in PJM / MISO / ERCOT (SPP also ~10 GW; Southern ~8 GW)