Overview

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.

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Use with MCP

This table is readable two ways, over the same guarded boundary. Over HTTP: POST /api/v1/datasets/caiso_constraints_da/query, described in the API reference. Or from an MCP client: connect a market below, then use search_data or describe_data to load its query contract before calling query_data.

CAISO MCP Server

Schema4

Column

Type

event_timeDateTime64(6, 'UTC')

constraint_nameLowCardinality(String)

constraint_causeLowCardinality(String)

shadow_price_usd_mwhNullable(Float64)

Sample rows

event_time	constraint_name	constraint_cause	shadow_price_usd_mwh
2026-08-27 23:00:00.000000	7690-CONTRL-INYOKN_EXP_NG	Base Case	-25.73822
2026-08-27 23:00:00.000000	39021_SC21ATP _70.0_34888_ARVIN _70.0_BR_1 _1	PG1 WHELRG-WEEDPC 70	912.20335
2026-08-27 23:00:00.000000	36851_NORTHERN_115_36852_SCOTT _115_BR_2 _1	PG1 NRTHRN-SCOTT_1 115	127.71529
2026-08-27 23:00:00.000000	34706_WESTPARK_115_34752_KERN PWR_115_BR_1 _1	PG1 KERNPP-WESTPK_2 115	2.45847
2026-08-27 23:00:00.000000	34116_LE GRAND_115_34115_ADRA TAP_115_BR_1 _1	PG1 MNDOTA-PNOCHE 115	70.89946
2026-08-27 23:00:00.000000	34101_CERTANJ2_115_34116_LE GRAND_115_BR_1 _1	PG1 WILSON-LGRAND 115	2.62823
2026-08-27 23:00:00.000000	31336_HPLND JT_60.0_31370_CLVRDLJT_60.0_BR_1 _1	PG1 EGLRK-SLVR-FLTN 115_M	102.06749
2026-08-27 23:00:00.000000	30060_MIDWAY _500_24156_VINCENT _500_BR_2 _3	SC1 MIDWAY-WHIRWD_1 500	27.76695
2026-08-27 23:00:00.000000	22604_OTAY _69.0_22616_OTAYLKTP_69.0_BR_1 _1	Base Case	2820.99534
2026-08-27 23:00:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	SD1 LCOCHS-GR-MIGUEL 69	253.23869
2026-08-27 22:00:00.000000	7690-CONTRL-INYOKN_EXP_NG	Base Case	-36.91252
2026-08-27 22:00:00.000000	39021_SC21ATP _70.0_34888_ARVIN _70.0_BR_1 _1	PG1 WHELRG-WEEDPC 70	772.80898
2026-08-27 22:00:00.000000	36851_NORTHERN_115_36852_SCOTT _115_BR_2 _1	PG1 NRTHRN-SCOTT_1 115	51.44247
2026-08-27 22:00:00.000000	34548_KETTLEMN_70.0_34552_GATES _70.0_BR_1 _1	Base Case	14.58786
2026-08-27 22:00:00.000000	34418_KINGSBRG_115_34428_CONTADNA_115_BR_1 _1	PG1 MCCALL-MSTANS 230	26.24727
2026-08-27 22:00:00.000000	34116_LE GRAND_115_34115_ADRA TAP_115_BR_1 _1	PG1 MNDOTA-PNOCHE 115	68.60164
2026-08-27 22:00:00.000000	31336_HPLND JT_60.0_31370_CLVRDLJT_60.0_BR_1 _1	PG1 EGLRK-SLVR-FLTN 115_M	117.26655
2026-08-27 22:00:00.000000	29400_ANTELOPE_500_29402_WIRLWIND_500_BR_1 _1	SC1 VINCNT-WHIRWD_1 500	33.40442
2026-08-27 22:00:00.000000	22604_OTAY _69.0_22616_OTAYLKTP_69.0_BR_1 _1	Base Case	1720.12114
2026-08-27 22:00:00.000000	22404_LILAC _69.0_22624_PALA _69.0_BR_1 _1	SD1 PNDLTN-SANLUS 69	10.59711
2026-08-27 22:00:00.000000	22208_EL CAJON_69.0_22408_LOSCOCHS_69.0_BR_1 _1	SD1 LCOCHS-GR-MIGUEL 69	236.8913
2026-08-27 21:00:00.000000	HUMBOLDT_EXP_NG	Base Case	-14.57826
2026-08-27 21:00:00.000000	7820_TL649A_OVERLOAD_NG	Base Case	-7.09866
2026-08-27 21:00:00.000000	7690-CONTRL-INYOKN_EXP_NG	Base Case	-28.47878
2026-08-27 21:00:00.000000	39021_SC21ATP _70.0_34888_ARVIN _70.0_BR_1 _1	PG1 WHELRG-WEEDPC 70	679.67972

Coverage

100.0% complete2 gap days4,255 days with data

Show coverage history ▾

Coverage: 100.0%Days with data: 4,255Gaps: 2

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More data from CAISO

Battery Storage Net OutputObserved five-minute net output from standalone and hybrid battery storage across the CAISO footprint. The total supply_mw field is positive when batteries are discharging into the grid and negative when they are charging from the grid; standalone_batteries_mw and hybrid_batteries_mw are components of that total, not additional generation to add on top. This is the live operating series published in CAISO Today's Outlook, not nameplate capacity or state of charge.CAISO Day-Ahead Ancillary PricesCleared day-ahead ancillary-service capacity prices in CAISO, one row per hour, AS region and product. 2,172,326 rows, 2014-12 to now. Products: reg_up, reg_down, spin, non_spin, reg_mileage_up, reg_mileage_down. 12 CAISO ancillary-service regions (AS_CAISO, AS_NP26, AS_SP26 and their expanded variants). The expanded regions overlap the base ones by design — never sum across regions. price_usd_mw is a price for CAPACITY held in reserve — dollars per megawatt of commitment — not dollars per megawatt-hour of energy delivered. The two are different units and are not comparable to an LMP.CAISO Day-Ahead Load ForecastCAISO's day-ahead demand forecast, one row per forecast hour with a system total and one column per TAC area. 75,727 hours, 2018-01 through the next delivery day. Column-for-column identical to CAISO Load (caiso_load) on purpose: system_mw, pge_mw, sce_mw, sdge_mw, vea_mw, mwd_mw. Forecast-versus-actual is therefore a plain join on event_time with no reshaping on either side. CAISO publishes no issue-time column for this feed, so there is no vintage axis here — this is the day-ahead market run for each hour, not a curve of successive forecasts. CAISO's other horizons (two-day, seven-day, real-time) live in caiso.load_forecast_horizons and only begin in May 2026.CAISO Day-Ahead PricesCAISO day-ahead locational marginal prices, one row per interval and location. 1.21B rows, 2016-01 to the next delivery day. Carries price_usd_mwh only. The component columns exist in the raw CAISO day-ahead feed but are entirely NULL in it, so this table carries no decomposition rather than four empty columns. Locations are node (26k — including the TH_ trading hubs such as TH_SP15_GEN-APND; CAISO has no 'hub' kind), interface (the ties), zone (6 aggregates only); location_id joins atg.caiso_locations for the readable name, and kind is carried inline so a hub-only or zone-only question needs no join at all. Every market's day-ahead price table in this catalog has these same column names, so a cross-market price comparison is a UNION rather than a per-ISO rewrite. Revisions are already collapsed — read it plainly.