Nomogram Shadow Prices (5-minute)

CAISO OASIS 5-minute real-time interval shadow prices on nomogram constraints.

Congestion & Constraints data

Download data

Native record

nomogram or branch constraint x 5-minute interval

5-minute publication cadence

Evidence

Observed market data

Published observations from the named source

Time basis

Point-in-time records

UTC · event_time

Overview

A nomogram is a multi-element stability or transfer limit (a relationship across several branches or interfaces rather than a single line), so a binding nomogram shadow price flags where a security constraint — not just one overloaded line — is driving congestion cost. Useful for understanding structural transmission limits and stability-driven congestion in the CAISO footprint, complementing the single-branch and intertie shadow prices. History spans 2015 to present at ~99% daily coverage. The official source is CAISO OASIS.

Query contract

Preserve one canonical row per (event_time, nomogram_id) before aggregating.

Analysis rules

Group only after preserving the declared grain: event_time, nomogram_id.

Schema5

Column

Type

event_timeDateTime64(6, 'UTC')

nomogram_idLowCardinality(String)

prcNullable(Float64)

constraint_causeNullable(String)

ingested_atDateTime64(6, 'UTC')

Sample data

event_time	nomogram_id	prc	constraint_cause	ingested_at
2026-09-30 05:45:00.000000	31336_HPLND JT_60.0_31370_CLVRDLJT_60.0_BR_1 _1	236.83393	PG1 EGLRK-SLVR-FLTN 115_M	2026-09-30 05:47:45.406555
2026-09-30 05:45:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	84.53839	SD1 LCOCHS-GR-MIGUEL 69	2026-09-30 05:47:45.406555
2026-09-30 05:40:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	82.48897	SD1 LCOCHS-GR-MIGUEL 69	2026-09-30 05:47:45.406555
2026-09-30 05:35:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	80.82838	SD1 LCOCHS-GR-MIGUEL 69	2026-09-30 05:47:45.406555
2026-09-30 05:35:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	80.82838	SD1 LCOCHS-GR-MIGUEL 69	2026-09-30 05:37:44.791859
2026-09-30 05:30:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	80.86629	SD1 LCOCHS-GR-MIGUEL 69	2026-09-30 05:47:45.406555
2026-09-30 05:30:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	80.86629	SD1 LCOCHS-GR-MIGUEL 69	2026-09-30 05:37:44.791859
2026-09-30 05:25:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	81.8937	SD1 LCOCHS-GR-MIGUEL 69	2026-09-30 05:47:45.406555
2026-09-30 05:25:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	81.8937	SD1 LCOCHS-GR-MIGUEL 69	2026-09-30 05:37:44.791859
2026-09-30 05:25:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	81.8937	SD1 LCOCHS-GR-MIGUEL 69	2026-09-30 05:27:44.177659
2026-09-30 05:20:00.000000	22831_SYCAMORE_138_22124_CHCARITA_138_BR_1 _1	2.67548	SD1 SXCYN-ARTRAN 230	2026-09-30 05:47:45.406555
2026-09-30 05:20:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	80.38901	SD1 LCOCHS-GR-MIGUEL 69	2026-09-30 05:47:45.406555
2026-09-30 05:20:00.000000	22831_SYCAMORE_138_22124_CHCARITA_138_BR_1 _1	2.67548	SD1 SXCYN-ARTRAN 230	2026-09-30 05:37:44.791859
2026-09-30 05:20:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	80.38901	SD1 LCOCHS-GR-MIGUEL 69	2026-09-30 05:37:44.791859
2026-09-30 05:20:00.000000	22831_SYCAMORE_138_22124_CHCARITA_138_BR_1 _1	2.67548	SD1 SXCYN-ARTRAN 230	2026-09-30 05:27:44.177659
2026-09-30 05:20:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	80.38901	SD1 LCOCHS-GR-MIGUEL 69	2026-09-30 05:27:44.177659
2026-09-30 05:15:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	81.16661	SD1 LCOCHS-GR-MIGUEL 69	2026-09-30 05:47:45.406555
2026-09-30 05:15:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	81.16661	SD1 LCOCHS-GR-MIGUEL 69	2026-09-30 05:37:44.791859
2026-09-30 05:15:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	81.16661	SD1 LCOCHS-GR-MIGUEL 69	2026-09-30 05:27:44.177659
2026-09-30 05:10:00.000000	7820_TL 230S_OVERLOAD_NG	-0.12308	Base Case	2026-09-30 05:47:45.406555
2026-09-30 05:10:00.000000	22831_SYCAMORE_138_22124_CHCARITA_138_BR_1 _1	3.61891	SD1 SXCYN-ARTRAN 230	2026-09-30 05:47:45.406555
2026-09-30 05:10:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	133.21371	SD1 LCOCHS-GR-MIGUEL 69	2026-09-30 05:47:45.406555
2026-09-30 05:10:00.000000	7820_TL 230S_OVERLOAD_NG	-0.12308	Base Case	2026-09-30 05:37:44.791859
2026-09-30 05:10:00.000000	22831_SYCAMORE_138_22124_CHCARITA_138_BR_1 _1	3.61891	SD1 SXCYN-ARTRAN 230	2026-09-30 05:37:44.791859
2026-09-30 05:10:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	133.21371	SD1 LCOCHS-GR-MIGUEL 69	2026-09-30 05:37:44.791859

Coverage

99.3% complete32 gap days4,259 days with data

Show coverage history

Coverage: 99.3%Days with data: 4,259Gaps: 32

2026

2025

2024

2023

2022

2021

2020

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2018

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2015

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Related congestion & constraints data

Related congestion & constraints data
Dataset	Description
CAISO Day-Ahead Binding ConstraintsCAISO · hourly	Which transmission facilities bound in CAISO's day-ahead market and what each one cost, one row per interval and constraint. 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.
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.