What is NYISO
The New York Independent System Operator runs the state's power grid and its wholesale electricity markets — every generator dispatched, every five-minute price, and the summer peak hour that sets a year of capacity bills, for the whole state from Buffalo to Montauk.
One state, eleven zones
NYISO divides New York into 11 load zones, lettered A through K running roughly west to east: Buffalo is Zone A, Albany's Capital region is F, New York City is J, Long Island is K. Prices differ by zone because the wires between them congest — most generation sits upstate, most load sits downstate, and on a hot afternoon the corridors between them run full. The city routinely clears at multiples of the western zones.
The peak that costs money
Once each summer, statewide load hits its annual maximum — recently between 29 and 32 gigawatts, always on a hot business-day afternoon. Your demand during that single hour becomes your ICAP tag, the number capacity charges multiply against for the following year. The ICAP explainer has the mechanics and the math.
Watching it live
NYISO publishes its data openly: five-minute load and prices, hourly forecasts, settled history. The live NYISO dashboard turns that into one answer — will today set the peak? — each business morning by 10 AM ET, with live zone prices and grid conditions alongside, and a public track record grading every call.