Overview

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.

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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_rt/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

Schema6

Column

Type

event_timeDateTime64(6, 'UTC')

constraint_nameLowCardinality(String)

constraint_typeLowCardinality(String)

directionLowCardinality(String)

constraint_causeLowCardinality(String)

shadow_price_usd_mwhNullable(Float64)

Sample rows

event_time	constraint_name	constraint_type	direction	constraint_cause	shadow_price_usd_mwh
2026-08-28 02:25:00.000000	34724_KRN OL J_115_34736_MAGUNDEN_115_BR_1 _1	nomogram		PG1 WESTPK LD2 115_M	25.46197
2026-08-28 02:25:00.000000	34418_KINGSBRG_115_34428_CONTADNA_115_BR_1 _1	nomogram		PG1 MCCALL-MSTANS 230	28.95977
2026-08-28 02:25:00.000000	34101_CERTANJ2_115_34116_LE GRAND_115_BR_1 _1	nomogram		PG1 MCCALL-MSTANS 230	304.68693
2026-08-28 02:25:00.000000	31486_CARIBOU _115_30255_CARBOU M_ 1.0_XF_11	nomogram		Base Case	41.44382
2026-08-28 02:25:00.000000	31336_HPLND JT_60.0_31370_CLVRDLJT_60.0_BR_1 _1	nomogram		PG1 EGLRK-SLVR-FLTN 115_M	269.37622
2026-08-28 02:25:00.000000	30060_MIDWAY _500_24156_VINCENT _500_BR_2 _3	nomogram		SC1 MIDWAY-WHIRWD_1 500	106.20994
2026-08-28 02:20:00.000000	7690-CONTRL-INYOKN_EXP_NG	nomogram		Base Case	-2.33425
2026-08-28 02:20:00.000000	34724_KRN OL J_115_34736_MAGUNDEN_115_BR_1 _1	nomogram		PG1 WESTPK LD2 115_M	19.75505
2026-08-28 02:20:00.000000	34418_KINGSBRG_115_34428_CONTADNA_115_BR_1 _1	nomogram		PG1 MCCALL-MSTANS 230	26.92807
2026-08-28 02:20:00.000000	34101_CERTANJ2_115_34116_LE GRAND_115_BR_1 _1	nomogram		PG1 MCCALL-MSTANS 230	298.77749
2026-08-28 02:20:00.000000	31486_CARIBOU _115_30255_CARBOU M_ 1.0_XF_11	nomogram		Base Case	40.71797
2026-08-28 02:20:00.000000	31336_HPLND JT_60.0_31370_CLVRDLJT_60.0_BR_1 _1	nomogram		PG1 EGLRK-SLVR-FLTN 115_M	264.4511
2026-08-28 02:20:00.000000	30060_MIDWAY _500_24156_VINCENT _500_BR_2 _3	nomogram		SC1 MIDWAY-WHIRWD_1 500	105.88435
2026-08-28 02:20:00.000000	LDWP_IPP_NORTH	intertie	import	Base Case	-33.67002
2026-08-28 02:15:00.000000	7690-CONTRL-INYOKN_EXP_NG	nomogram		Base Case	-39.58718
2026-08-28 02:15:00.000000	34724_KRN OL J_115_34736_MAGUNDEN_115_BR_1 _1	nomogram		PG1 WESTPK LD2 115_M	20.21586
2026-08-28 02:15:00.000000	34418_KINGSBRG_115_34428_CONTADNA_115_BR_1 _1	nomogram		PG1 MCCALL-MSTANS 230	25.63531
2026-08-28 02:15:00.000000	34101_CERTANJ2_115_34116_LE GRAND_115_BR_1 _1	nomogram		PG1 MCCALL-MSTANS 230	294.8128
2026-08-28 02:15:00.000000	31486_CARIBOU _115_30255_CARBOU M_ 1.0_XF_11	nomogram		Base Case	40.1792
2026-08-28 02:15:00.000000	31336_HPLND JT_60.0_31370_CLVRDLJT_60.0_BR_1 _1	nomogram		PG1 EGLRK-SLVR-FLTN 115_M	260.27182
2026-08-28 02:15:00.000000	30060_MIDWAY _500_24156_VINCENT _500_BR_2 _3	nomogram		SC1 MIDWAY-WHIRWD_1 500	99.52025
2026-08-28 02:15:00.000000	LDWP_IPP_NORTH	intertie	import	Base Case	-31.64504
2026-08-28 02:10:00.000000	7690-CONTRL-INYOKN_EXP_NG	nomogram		Base Case	-52.83818
2026-08-28 02:10:00.000000	34724_KRN OL J_115_34736_MAGUNDEN_115_BR_1 _1	nomogram		PG1 WESTPK LD2 115_M	24.39547
2026-08-28 02:10:00.000000	34418_KINGSBRG_115_34428_CONTADNA_115_BR_1 _1	nomogram		PG1 MCCALL-MSTANS 230	31.94554

Coverage

100.0% complete1 gap days4,257 days with data

Show coverage history ▾

Coverage: 100.0%Days with data: 4,257Gaps: 1

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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 Binding ConstraintsWhich 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 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.