CAISO Day-Ahead Binding Constraints

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

Congestion & Constraints data CAISO 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

463,496 rows, 2015-01 to now. Columns: event_time, constraint_name, shadow_price_usd_mwh, plus constraint_cause. 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.

CAISO MCP API reference

HTTP endpoint

POST /api/v1/datasets/caiso_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)

constraint_causeLowCardinality(String)

shadow_price_usd_mwhNullable(Float64)

Sample data

event_time	constraint_name	constraint_cause	shadow_price_usd_mwh
2026-10-12 05:00:00.000000	7820_TL 230S_OVERLOAD_NG	Base Case	-2.62498
2026-10-12 05:00:00.000000	7690-CONTRL-INYOKN_EXP_NG	Base Case	0
2026-10-12 05:00:00.000000	32225_BRNSWKT1_115_32222_DTCH2TAP_115_BR_1 _1	Base Case	26.88696
2026-10-12 05:00:00.000000	31336_HPLND JT_60.0_31370_CLVRDLJT_60.0_BR_1 _1	PG1 EGLRK-SLVR-FLTN 115_M	246.82198
2026-10-12 05:00:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	SD1 LCOCHS-GR-MIGUEL 69	19.33305
2026-10-12 04:00:00.000000	7820_TL 230S_OVERLOAD_NG	Base Case	-1.90829
2026-10-12 04:00:00.000000	7690-CONTRL-INYOKN_EXP_NG	Base Case	0
2026-10-12 04:00:00.000000	32225_BRNSWKT1_115_32222_DTCH2TAP_115_BR_1 _1	Base Case	28.5222
2026-10-12 04:00:00.000000	31336_HPLND JT_60.0_31370_CLVRDLJT_60.0_BR_1 _1	PG1 EGLRK-SLVR-FLTN 115_M	266.86533
2026-10-12 04:00:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	SD1 LCOCHS-GR-MIGUEL 69	13.72829
2026-10-12 03:00:00.000000	7690-CONTRL-INYOKN_EXP_NG	Base Case	0
2026-10-12 03:00:00.000000	32225_BRNSWKT1_115_32222_DTCH2TAP_115_BR_1 _1	Base Case	25.98305
2026-10-12 03:00:00.000000	31336_HPLND JT_60.0_31370_CLVRDLJT_60.0_BR_1 _1	PG1 EGLRK-SLVR-FLTN 115_M	269.48135
2026-10-12 03:00:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	SD1 LCOCHS-GR-MIGUEL 69	41.91586
2026-10-12 02:00:00.000000	7690-CONTRL-INYOKN_EXP_NG	Base Case	0
2026-10-12 02:00:00.000000	34101_CERTANJ2_115_34116_LE GRAND_115_BR_1 _1	Base Case	0.11665
2026-10-12 02:00:00.000000	32225_BRNSWKT1_115_32222_DTCH2TAP_115_BR_1 _1	Base Case	26.10744
2026-10-12 02:00:00.000000	31336_HPLND JT_60.0_31370_CLVRDLJT_60.0_BR_1 _1	PG1 EGLRK-SLVR-FLTN 115_M	272.87762
2026-10-12 02:00:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	SD1 LCOCHS-GR-MIGUEL 69	63.05939
2026-10-12 01:00:00.000000	7690-CONTRL-INYOKN_EXP_NG	Base Case	-57.04508
2026-10-12 01:00:00.000000	32225_BRNSWKT1_115_32222_DTCH2TAP_115_BR_1 _1	Base Case	10.60139
2026-10-12 01:00:00.000000	31336_HPLND JT_60.0_31370_CLVRDLJT_60.0_BR_1 _1	PG1 EGLRK-SLVR-FLTN 115_M	271.24316
2026-10-12 01:00:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	SD1 LCOCHS-GR-MIGUEL 69	69.31605
2026-10-12 00:00:00.000000	7690-CONTRL-INYOKN_EXP_NG	Base Case	-56.24937
2026-10-12 00:00:00.000000	35618_SN JSE A_115_35616_SNJOSEB _115_BR_1 _1	PG1 LOSEST-METCLF 230	12.08183

Coverage

100.0% complete2 gap days4,301 days with data

Show coverage history

Coverage: 100.0%Days with data: 4,301Gaps: 2

2026

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2015

gaplessmore

Related congestion & constraints data

Related congestion & constraints data
Dataset	Description
CAISO Real-Time Binding ConstraintsCAISO · 5-minute	Which transmission facilities bound in CAISO's real-time market and what each one cost, one row per interval and constraint. 6.43M rows, 2015-01 to now. Columns: event_time, constraint_name, shadow_price_usd_mwh, plus constraint_type ('intertie', 4.06M rows, or 'nomogram', 2.36M), direction, and constraint_cause. 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.
Constraint Shift Factor RunsCAISO · nightly (one row per completed run)	One row per COMPLETED nightly estimation of CAISO 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.caiso_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)CAISO · nightly (60-day rolling estimation window)	Estimated sensitivity of every CAISO 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 CAISO's INTERTIE AND NOMOGRAM constraints, not internal transmission branches, over roughly 19,400 pricing nodes. CAISO publishes no contingency or terminal names on this feed, so contingency_name, from_station and to_station are always empty. 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.
Intertie Constraint Shadow Prices (5-minute)CAISO · 5-minute	CAISO OASIS 5-minute real-time shadow prices on intertie / scheduling-point constraints, by tie and flow direction. The shadow price is the marginal cost of a binding intertie limit, so this is the direct signal for congestion between CAISO and neighboring balancing areas: a non-zero price means an import/export path is constrained and is shaping locational prices at the border. Traders use it to explain inter-BAA basis and to see which ties are binding and in which direction, and operators use it to track where transfer limits are actively holding back scheduling. History spans 2015 to present at ~99% daily coverage. The official source is CAISO OASIS.