Overview
Cleared 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.
Use with MCP
This table is readable two ways, over the same guarded boundary. Over HTTP: POST /api/v1/datasets/caiso_ancillary_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.
Schema4
event_timeDateTime64(6, 'UTC')regionLowCardinality(String)productLowCardinality(String)price_usd_mwNullable(Float64)Sample rows
| event_time | region | product | price_usd_mw |
|---|---|---|---|
| 2026-08-28 06:00:00.000000 | AS_SP26_EXP | non_spin | 0 |
| 2026-08-28 06:00:00.000000 | AS_NP26 | reg_down | 0 |
| 2026-08-28 06:00:00.000000 | AS_CAISO_EXP | non_spin | 7.33578 |
| 2026-08-28 06:00:00.000000 | AS_CAISO | non_spin | 0 |
| 2026-08-28 06:00:00.000000 | AS_NP26_EXP | non_spin | 0 |
| 2026-08-28 06:00:00.000000 | AS_SP26 | non_spin | 0 |
| 2026-08-28 06:00:00.000000 | AS_NP26 | non_spin | 0 |
| 2026-08-28 06:00:00.000000 | AS_CAISO | reg_down | 0.79337 |
| 2026-08-28 06:00:00.000000 | AS_CAISO_EXP | reg_down | 4.65 |
| 2026-08-28 06:00:00.000000 | AS_SP26_EXP | reg_down | 0 |
| 2026-08-28 06:00:00.000000 | AS_SP26 | reg_up | 0 |
| 2026-08-28 06:00:00.000000 | AS_NP26_EXP | reg_up | 0 |
| 2026-08-28 06:00:00.000000 | AS_NP26 | reg_up | 0 |
| 2026-08-28 06:00:00.000000 | AS_SP26_EXP | reg_up | 0 |
| 2026-08-28 06:00:00.000000 | AS_CAISO_EXP | reg_up | 7.33578 |
| 2026-08-28 06:00:00.000000 | AS_CAISO | reg_up | 0 |
| 2026-08-28 06:00:00.000000 | AS_CAISO_EXP | reg_mileage_up | 0 |
| 2026-08-28 06:00:00.000000 | AS_CAISO_EXP | reg_mileage_down | 0 |
| 2026-08-28 06:00:00.000000 | AS_CAISO | spin | 0 |
| 2026-08-28 06:00:00.000000 | AS_SP26 | reg_down | 0 |
| 2026-08-28 06:00:00.000000 | AS_NP26_EXP | reg_down | 0.51536 |
| 2026-08-28 06:00:00.000000 | AS_SP26 | spin | 0 |
| 2026-08-28 06:00:00.000000 | AS_CAISO_EXP | spin | 7.33578 |
| 2026-08-28 06:00:00.000000 | AS_NP26 | spin | 0 |
| 2026-08-28 06:00:00.000000 | AS_NP26_EXP | spin | 0 |