ERCOT Real-Time Binding Constraints

Which transmission facilities bound in ERCOT's real-time market and what each one cost, one row per interval and constraint.

Congestion & Constraints data ERCOT market

Query with the agent

Native record

constraint x dispatch interval

5-minute (SCED) publication cadence

Evidence

Observed market data

Published observations from the named source

Time basis

Interval-start records

UTC · event_time

Overview

8.42M rows, 2014-05 to now. Columns: event_time, constraint_name, shadow_price_usd_mwh, plus contingency (the outage the limit is evaluated against), from_station and to_station (the ends of the constrained element), limit_mw and flow_mw. 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.

ERCOT MCP API reference

HTTP endpoint

POST /api/v1/datasets/ercot_constraints_rt/query

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

Schema8

Column

Type

event_timeDateTime64(6, 'UTC')

constraint_nameLowCardinality(String)

contingencyLowCardinality(String)

from_stationLowCardinality(Nullable(String))

to_stationLowCardinality(Nullable(String))

shadow_price_usd_mwhNullable(Float64)

limit_mwNullable(Float64)

flow_mwNullable(Float64)

Sample data

event_time	constraint_name	contingency	from_station	to_station	shadow_price_usd_mwh	limit_mw	flow_mw
2026-10-12 09:55:19.000000	WESTEX	BASE CASE	∅	∅	0	9873.6	7905.8
2026-10-12 09:55:19.000000	TREADW_YELWJC1_1	DBUCRGP5	TREADWEL	YELWJCKT	59.64016	204.8	204.8
2026-10-12 09:55:19.000000	SN_STR26_A	SNEWGLF8	SN	STR	27.39368	291.9	291.9
2026-10-12 09:55:19.000000	KLNSW_MR1H	DSALKLN5	KLNSW	KLNSW	217.04822	745.6	745.6
2026-10-12 09:55:19.000000	HHGTOM_1	BASE CASE	HHGT	OMEGA	66.82891	750.5	750.5
2026-10-12 09:55:19.000000	CROSSO_PALOUS1_1	SWOLPAL8	PALOUSE	CROSSOVE	0	182.8	172.1
2026-10-12 09:55:19.000000	BLESSING_1382	DSTPSTA5	BLESSING	BLESSING	0	425.2	413.1
2026-10-12 09:55:19.000000	6437__F	DMTSCOS5	SCRCV	KNAPP	0	229.9	206.9
2026-10-12 09:55:19.000000	138_FWP_MNL_1	SALVTNN8	FRWYPARK	MAINLAND	0	383.8	199.5
2026-10-12 09:55:19.000000	1020__A	DELMWWE8	ELMOT	MCTYE	33.14442	217.9	217.9
2026-10-12 09:50:19.000000	WESTEX	BASE CASE	∅	∅	0	9873.6	7868.4
2026-10-12 09:50:19.000000	TREADW_YELWJC1_1	DBUCRGP5	TREADWEL	YELWJCKT	59.53268	204.8	204.8
2026-10-12 09:50:19.000000	SN_STR26_A	SNEWGLF8	SN	STR	20.04672	291.6	291.6
2026-10-12 09:50:19.000000	KLNSW_MR1H	DSALKLN5	KLNSW	KLNSW	216.85191	745.5	745.5
2026-10-12 09:50:19.000000	HHGTOM_1	BASE CASE	HHGT	OMEGA	66.79801	750.5	750.5
2026-10-12 09:50:19.000000	CROSSO_PALOUS1_1	SWOLPAL8	PALOUSE	CROSSOVE	0	182.8	172.4
2026-10-12 09:50:19.000000	BLESSING_1382	DSTPSTA5	BLESSING	BLESSING	0	425.1	414.6
2026-10-12 09:50:19.000000	6437__F	DMTSCOS5	SCRCV	KNAPP	0	230	206.6
2026-10-12 09:50:19.000000	138_FWP_MNL_1	SALVTNN8	FRWYPARK	MAINLAND	0	384	81.8
2026-10-12 09:50:19.000000	1020__A	DELMWWE8	ELMOT	MCTYE	32.92673	217.9	217.9
2026-10-12 09:45:19.000000	WESTEX	BASE CASE	∅	∅	0	9873.6	7891.5
2026-10-12 09:45:19.000000	TREADW_YELWJC1_1	DBUCRGP5	TREADWEL	YELWJCKT	59.46072	204.8	204.8
2026-10-12 09:45:19.000000	SN_STR26_A	SNEWGLF8	SN	STR	2.68494	291.6	291.6
2026-10-12 09:45:19.000000	KLNSW_MR1H	DSALKLN5	KLNSW	KLNSW	216.63338	745.6	745.6
2026-10-12 09:45:19.000000	HHGTOM_1	BASE CASE	HHGT	OMEGA	66.85232	750.5	750.5

Coverage

99.7% complete15 gap days4,533 days with data

Show coverage history

Coverage: 99.7%Days with data: 4,533Gaps: 15

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Related congestion & constraints data

Related congestion & constraints data
Dataset	Description
Constraint Shift Factor RunsERCOT · nightly (one row per completed run)	One row per COMPLETED nightly estimation of ERCOT constraint shift factors, and the only record that a run finished. Resolve the latest usable run here — computed_at = (SELECT max(computed_at) FROM atg.ercot_constraint_sensitivity_runs) — and never off max(computed_at) of the sensitivities themselves, because a run writes its rows in blocks that all carry the new timestamp and an unfinished or abandoned run would otherwise look like the newest one. Each row also carries how much evidence that run had: interval_coverage is the fraction of published dispatch intervals that survived admission, intervals_refused_unexplained counts intervals showing congestion with no constraint recorded as binding (an unobserved binding set), constraint_feed_lag_minutes is how far the constraint feed trailed the price feed, and constraints_seen / constraints_in_fit / constraints_reported show how many constraints bound, how many were good enough to control for, and how many earned a published estimate.
Constraint Shift Factors (Estimated)ERCOT · nightly (60-day rolling estimation window)	Estimated sensitivity of every ERCOT pricing location's price to every binding transmission constraint: one row per constraint, contingency, and location, recomputed nightly over a rolling 60-day window. This is what answers 'which nodes drive this constraint' and 'which constraints is this node exposed to'. Covers ERCOT's transmission constraints with their contingency and both named terminals, over 1,123 settlement points. shift_factor is in the ISO's orientation — POSITIVE means an incremental MW injected at that node increases loading on the constraint and the node is paid below system lambda while it binds; NEGATIVE means generation there relieves the constraint and earns a premium. These are ESTIMATES recovered from the price identity LMP = energy - sum(shift_factor x shadow_price), not a published PTDF matrix. They are measured RELATIVE TO THE MARKET'S REFERENCE — the identity yields SF(node) - SF(reference), so a single absolute value should be quoted as 'relative to the system reference' rather than as the node's PTDF, while DIFFERENCES between nodes are exact because the reference term cancels. Three further differences from a published matrix: they describe a NODE (a generator at that node inherits its location's value, and two units at one node are indistinguishable), they reflect the topology actually in effect across the window including outages rather than a stated base case, and every one carries a std_error from a 200-draw block bootstrap that resamples whole days. Read std_error before quoting shift_factor: an estimate whose absolute value is not at least twice its standard error is not distinguishable from zero. estimation_status says why a row has no number — 'thin_support' (in the fit, so it is controlled for, but under 12 binding intervals or under 3 distinct binding days), 'no_support' (under 3 binding intervals; not a regressor), or 'collinear' (it bound in lockstep with another constraint, so the two cannot be separated). Where from_station and to_station are populated they identify the monitored element and are NOT the constrained direction — the sign of shift_factor is what says which way. Every read must pin computed_at to one run, and must resolve that run through the companion atg.<iso>_constraint_sensitivity_runs ledger rather than off max(computed_at) here — rows are written in blocks that all carry the new timestamp, so an unfinished or abandoned run would otherwise look like the newest. Mixing runs averages a node across different network topologies.
CRR Monthly Auction ResultsERCOT · monthly auction posting	Cleared ERCOT monthly Congestion Revenue Right auction awards, one row per source-to-sink CRR and time-of-use block, including awarded MW and the auction shadow price per MWh. This is public auction evidence for who acquired a path and at what clearing price. It does not contain realized day-ahead congestion settlements, fees, later trades, the holder's full portfolio, or net profit, so auction cost must not be described as payout or profitability. The official source is ERCOT report NP7-803-M.
Day-Ahead Shadow Prices & Binding ConstraintsERCOT · hourly (DAM)	Binding transmission constraint and contingency pairs from ERCOT's Day-Ahead Market solution, one row per constraint, contingency, and delivery hour, including the limiting facility, its from and to stations, the constraint limit, flow, and violation in MW, and the shadow price. A row establishes that the named constraint bound in the cleared day-ahead solution for that hour and its marginal system cost. It does not, by itself, identify which settlement point or hub the constraint affected, or establish that the constraint bound in real time; the first requires shift-factor or direct attribution evidence, and real-time binding is recorded in the SCED shadow prices. The official source is ERCOT report NP4-191-CD.