NYISO Day-Ahead Binding Constraints

Which transmission facilities bound in NYISO's day-ahead market and what each one cost, one row per interval and constraint.

Congestion & Constraints data NYISO market

Query with the agent

Native record

constraint x delivery hour

hourly publication cadence

Evidence

Cleared day-ahead market

A market outcome, not a physical observation

Time basis

Interval-start records

UTC · event_time

Overview

1.02M rows, 2001-08 to the next delivery day. Columns: event_time, constraint_name, shadow_price_usd_mwh, plus contingency. The shadow price is the marginal cost of the binding limit — what the market would have saved from one more megawatt of capability on that element. This is the table that answers WHY congestion appeared; a price spread between two locations shows that they separated but not which facility separated them.

Query contract

A row means this constraint was binding in this interval. Absence of a row means it was not binding, not that it does not exist.

Analysis rules

Rank constraints by summed or averaged shadow price over a window, and say which — a constraint that binds rarely but hard ranks differently from one that binds constantly and cheaply.
Count binding INTERVALS, not rows, when describing how often a constraint bound.

Related analysis

explaining why a location's congestion component moved in an interval · align on event_time; the constraint explains the market-wide congestion pattern, not one location's share of it

Interpretation

A shadow price is the marginal value of relaxing the limit. It is not the amount of power that flowed, not a measure of how loaded the line was, and not a dollar cost anyone paid.
This table names the binding element. Attributing a specific location's congestion to a specific constraint additionally needs a shift factor, which is not published here.

Access

Query from your own tools

Use the guarded HTTP endpoint directly, or connect an MCP client and load the dataset contract with describe_data before calling query_data.

NYISO MCP API reference

HTTP endpoint

POST /api/v1/datasets/nyiso_constraints_da/query

Need the full history of this dataset in Snowflake, Databricks or your own storage? Data services delivers it on a schedule.

Schema4

Column

Type

event_timeDateTime64(6, 'UTC')

constraint_nameLowCardinality(String)

contingencyLowCardinality(String)

shadow_price_usd_mwhNullable(Float64)

Sample data

event_time	constraint_name	contingency	shadow_price_usd_mwh
2026-10-13 03:00:00.000000	FALCONER 115 MOONROAD 115 2	MOONROAD-FALCONER_115_175	-47.58
2026-10-13 02:00:00.000000	FALCONER 115 MOONROAD 115 2	MOONROAD-FALCONER_115_175	-48.76
2026-10-13 01:00:00.000000	LAKSUCSS 138 SHORE_RD 138 1	BASE CASE	-28.53
2026-10-13 01:00:00.000000	FALCONER 115 MOONROAD 115 2	MOONROAD-FALCONER_115_175	-51.57
2026-10-13 00:00:00.000000	LAKSUCSS 138 SHORE_RD 138 1	BASE CASE	-27.31
2026-10-13 00:00:00.000000	HQTL ACTIVE DNI	ACTIVE DNI	-8.18
2026-10-13 00:00:00.000000	FALCONER 115 MOONROAD 115 2	MOONROAD-FALCONER_115_175	-63.13
2026-10-12 23:00:00.000000	DUNWODIE 345 DUNWOODN 345 1	SCB:DUNW(4):W73&W89&Y50&BKS1	0.15
2026-10-12 23:00:00.000000	LAKSUCSS 138 SHORE_RD 138 1	BASE CASE	-8.01
2026-10-12 23:00:00.000000	MOTTHAVN 345 DUNWODIE 345 1	BASE CASE	-0.02
2026-10-12 23:00:00.000000	BARRETT 138 VALLYSTR 138 2	VALLYSTR-BARRETT__138_291	0.14
2026-10-12 23:00:00.000000	SCH - PJ - NY	BASE CASE	-19.58
2026-10-12 22:00:00.000000	SCH - PJ - NY	BASE CASE	-13.51
2026-10-12 22:00:00.000000	LAKSUCSS 138 SHORE_RD 138 1	BASE CASE	-20.89
2026-10-12 22:00:00.000000	RAINEY 138 VERNON 138 1	BASE CASE	-0.02
2026-10-12 22:00:00.000000	BARRETT 138 VALLYSTR 138 2	VALLYSTR-BARRETT__138_291	0.39
2026-10-12 21:00:00.000000	LAKSUCSS 138 SHORE_RD 138 1	BASE CASE	-16.07
2026-10-12 21:00:00.000000	DUNWODIE 345 DUNWOODN 345 1	SCB:DUNW(4):W73&W89&Y50&BKS1	0.15
2026-10-12 21:00:00.000000	NYCA ACTIVE DNI	ACTIVE DNI	0.64
2026-10-12 21:00:00.000000	MOTTHAVN 345 DUNWODIE 345 1	BASE CASE	-0.03
2026-10-12 21:00:00.000000	HQTL ACTIVE DNI	ACTIVE DNI	2.09
2026-10-12 20:00:00.000000	LAKSUCSS 138 SHORE_RD 138 1	BASE CASE	-40.96
2026-10-12 19:00:00.000000	LAKSUCSS 138 SHORE_RD 138 1	BASE CASE	-0.06
2026-10-12 17:00:00.000000	LOCUSTGR 138 SYOSSET 138 1	NRTHPORT_138_138_PS2	-0.8
2026-10-12 16:00:00.000000	MOTTHAVN 345 DUNWODIE 345 1	BASE CASE	-0.03

Coverage

100.0% complete0 gap days9,205 days with data

Show coverage history

Coverage: 100.0%Days with data: 9,205Gaps: 0

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Related congestion & constraints data

Related congestion & constraints data
Dataset	Description
Available & Total Transfer CapabilityNYISO · hourly / 15-minute market-run timesteps	NYISO available transfer capability and total transfer capability by interface and market run. The source rows are melted so DAM and HAM timesteps can be compared by interface over time.
Day-Ahead Limiting ConstraintsNYISO · hourly (DAM)	NYISO day-ahead limiting-constraint records for the market-clearing plan, including limiting facility, facility PTID, contingency, and constraint cost. Paired with day-ahead LBMP components, it helps explain expected congestion and transfer limits before real-time operations.
NYISO Real-Time Binding ConstraintsNYISO · 5-minute	Which transmission facilities bound in NYISO's real-time market and what each one cost, one row per interval and constraint. 5.87M rows, 2001-06 to now. Columns: event_time, constraint_name, shadow_price_usd_mwh, plus contingency. The shadow price is the marginal cost of the binding limit — what the market would have saved from one more megawatt of capability on that element. This is the table that answers WHY congestion appeared; a price spread between two locations shows that they separated but not which facility separated them.
Pre-Scheduled ATC/TTCNYISO · scheduled	NYISO long-term pre-scheduled available transfer capability and total transfer capability by interface. Use it for forward interface-capability context rather than live flows.