Public HIFLD transmission lines and substations across New York, shown with NYISO's eleven load zones. Orient an asset, county, or development area against the network geography, then open the same layers on the live map.
Transmission lines
2,058
Line segments, 69 kV and up
Substations
1,300
100 kV and up
345 kV and above
131
The bulk transfer backbone
| Voltage | Lines | Relative count |
|---|---|---|
| 500 kV and above | 4 | |
| 345–499 kV | 127 | |
| 200–344 kV | 76 | |
| 100–199 kV | 1,655 | |
See it on the live NYISO map, updating as the market publishes.
Open network mapThe transmission-line and substation features available in the Homeland Infrastructure Foundation-Level Data (HIFLD) public inventory, placed beside NYISO market zones on Ask the Grid's interactive map.
New York's transmission picture splits between generation-heavy upstate corridors and the constrained import paths feeding New York City and Long Island. Read the public line and substation geography against the zone boundaries to see which side of that split a site sits on, then take the electrical questions — available capability, constraints, feasibility — to the NYISO and utility study process.
The transmission lines and substations published in the HIFLD public inventory, drawn across NYISO's load zones. It is geographic reference data — the operational network model, line flows, and available transfer capability stay with NYISO.
It shows you where the public network geography runs, which is the starting point. Whether a specific point of interconnection works is settled by the applicable utility's and NYISO's study process.
Yes. The Ask the Grid catalog page documents the HIFLD transmission-line dataset, source, schema, and available coverage.
| 69–99 kV |
|---|
| 196 |
| Owner | Lines | 345 kV+ |
|---|---|---|
| NIAGARA MOHAWK POWER CORP. | 1,165 | 36 |
| NEW YORK STATE ELEC & GAS CORP | 207 | 3 |
| LONG ISLAND POWER AUTHORITY | 168 | 1 |
| CENTRAL HUDSON GAS & ELEC CORP | 88 | 14 |
| ROCHESTER GAS & ELECTRIC CORP | 73 | 2 |
| CONSOLIDATED EDISON CO-NY INC | 50 | 23 |
| PPL ELECTRIC UTILITIES CORP | 13 | 0 |
| ORANGE & ROCKLAND UTILS INC | 3 | 3 |
NYISO load across 11 zones
13,113 MW
As of Oct 12, 5:00 AM EDT
Largest zone right now
New York City
4,088 MW · 31.2% of the total
Zones reporting
11
NYISO's own zonal load feed
| Zone | Load | Share of total |
|---|---|---|
| New York CityN.Y.C. | 4,088 MW | 31.2% |
| Long IslandLONGIL | 1,579 MW | 12% |
| CentralCENTRL | 1,410 MW | 10.8% |
| WestWEST | 1,375 MW | 10.5% |
| CapitalCAPITL | 1,087 MW | 8.3% |
| Hudson ValleyHUD VL | 856 MW | 6.5% |
| GeneseeGENESE | 854 MW | 6.5% |
| Mohawk ValleyMHK VL | 673 MW | 5.1% |
| NorthNORTH | 528 MW | 4% |
| DunwoodieDUNWOD | 480 MW | 3.7% |
| MillwoodMILLWD | 183 MW | 1.4% |
MW, NYISO's published load for each zone at the latest interval.
What Ask the Grid's detectors found in NYISO's published data over the last two weeks. A story that recurred is shown once, at its latest day.
Binding constraint· on 3 days
Real-time dispatch reports Goudey–Laurel L 115 kV circuit 1 with a −$1,000/MWh shadow price under contingency E.TOWANDA-HILLSIDE_230_70&PAR, in the top 5% of what NYISO pays to hold a constraint; the largest of 3 current constraints. It bound on 3 of the previous 30 days.
Local congestion· on 2 days
WEST to CAPITL spans $46/MWh while Goudey–Laurel L 115 kV circuit 1 carries a −$1,000/MWh shadow price. It bound on 3 of the previous 30 days.
Load vs forecast· on 8 days
Actual demand averaged 15,379 MW over the hour the intraday demand forecast describes, against 14,504 MW forecast for it — +875 MW (+6.0%).
Binding constraint
Real-time dispatch reports Chemung–Nwaverly 115 kV circuit 1 with a $550/MWh shadow price under contingency SCB:WATRCURE(69/2B42)69&BK2, in the top 5% of what NYISO pays to hold a constraint; the largest of 3 current constraints. It bound on 12 of the previous 30 days.
Local congestion· on 3 days
WEST to MHK VL spans $39/MWh while Chemung–Nwaverly 115 kV circuit 1 carries a $550/MWh shadow price. It bound on 12 of the previous 30 days.
Local congestion
WEST to MHK VL spans $75/MWh while Barrett–Vallystr 138 kV circuit 2 carries a $110/MWh shadow price. It bound on 6 of the previous 30 days.
Local congestion· on 6 days
WEST to LONGIL spans $43/MWh while Laksucss–Shore Rd 138 kV circuit 1 carries a −$200/MWh shadow price. It bound on 14 of the previous 30 days.
Local congestion· on 2 days
WEST to N.Y.C. spans $107/MWh while E179THST–Hellgate 138 kV circuit 1 carries a −$0/MWh shadow price. It bound on 25 of the previous 30 days.
Local congestion
WEST to N.Y.C. spans $115/MWh while Carlplce–Stewrtav 138 kV circuit 1 carries a −$0/MWh shadow price. It bound on 7 of the previous 30 days.
Local congestion· on 3 days
WEST to DUNWOD spans $127/MWh while Goethals–Linden 230 kV circuit 1 carries a −$4,000/MWh shadow price. It has gone unheld for 5 minutes and bound on 14 of the previous 30 days.
Binding constraint· on 4 days
Real-time dispatch could not keep Goethals–Linden 230 kV circuit 1 within its limit under contingency SCB:RAMAPO(T1500-W72):W72&5018, so its −$4,000/MWh shadow price is NYISO's transmission demand curve rather than the cost of any resource. It has gone unheld for 5 minutes and bound on 14 of the previous 30 days.
Binding constraint· on 2 days
Real-time dispatch reports Hillside–E.TWANDA 230 kV circuit 1 with a −$1,000/MWh shadow price under contingency SHICKSHI-SUSQUEHA_500_5067, in the top 5% of what NYISO pays to hold a constraint. It bound on 9 of the previous 30 days.