PJM Day-Ahead Ancillary Prices

Cleared day-ahead ancillary-service capacity prices in PJM, one row per hour, reserve zone and product.

Ancillary Services data

Download data

Native record

product x region x delivery hour

hourly (day-ahead) publication cadence

Evidence

Cleared day-ahead market

A market outcome, not a physical observation

Time basis

Interval-start records

UTC · event_time

Overview

173,760 rows, 2022-10 to the next delivery day. Products: spin, primary_reserve, operating_30. 2 PJM reserve zones (RTO, and the Mid-Atlantic/Dominion subzone). primary_reserve is PJM's own name and is NOT the same set as another market's non_spin: it is the TOTAL 10-minute requirement, synchronized plus non-synchronized, so it overlaps spin rather than complementing it — spin + primary_reserve double-counts in PJM where it is additive elsewhere. Regulation is deliberately absent: PJM prices it in a separate feed (pjm.reg_prices) whose RMCP/RMCCP columns have not been mapped to this table's vocabulary with confidence. 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.

Query contract

Select one product and one region before aggregating. Each row is already the canonical cleared price for that combination.

Analysis rules

Never sum prices across products. Reserve products are separately procured markets and their prices do not add to a meaningful total.
Never sum or average across reserve zones without saying so; 2 pjm reserve zones (rto, and the mid-atlantic/dominion subzone). primary_reserve is pjm's own name and is not the same set as another market's non_spin: it is the total 10-minute requirement, synchronized plus non-synchronized, so it overlaps spin rather than complementing it — spin + primary_reserve double-counts in pjm where it is additive elsewhere. regulation is deliberately absent: pjm prices it in a separate feed (pjm.reg_prices) whose rmcp/rmccp columns have not been mapped to this table's vocabulary with confidence.

Interpretation

price_usd_mw is $/MW of capacity held, not $/MWh of energy. Do not compare it directly to an LMP, and do not multiply it by megawatt-hours.
A cleared price is what the day-ahead market settled at. It is not the quantity procured, not a scarcity measurement, and not evidence that reserves were short.

Schema4

Column

Type

event_timeDateTime64(6, 'UTC')

regionLowCardinality(String)

productLowCardinality(String)

price_usd_mwNullable(Float64)

Sample data

event_time	region	product	price_usd_mw
2026-09-21 01:00:00.000000	Mid-Atlantic/Dominion Reserve Subzone	spin	1
2026-09-21 01:00:00.000000	PJM RTO Reserve Zone	operating_30	0
2026-09-21 01:00:00.000000	Mid-Atlantic/Dominion Reserve Subzone	primary_reserve	1
2026-09-21 01:00:00.000000	PJM RTO Reserve Zone	primary_reserve	1
2026-09-21 01:00:00.000000	PJM RTO Reserve Zone	spin	1
2026-09-21 00:00:00.000000	PJM RTO Reserve Zone	spin	0.14
2026-09-21 00:00:00.000000	Mid-Atlantic/Dominion Reserve Subzone	spin	0.14
2026-09-21 00:00:00.000000	PJM RTO Reserve Zone	primary_reserve	0
2026-09-21 00:00:00.000000	PJM RTO Reserve Zone	operating_30	0
2026-09-21 00:00:00.000000	Mid-Atlantic/Dominion Reserve Subzone	primary_reserve	0
2026-09-20 23:00:00.000000	Mid-Atlantic/Dominion Reserve Subzone	spin	60.21
2026-09-20 23:00:00.000000	PJM RTO Reserve Zone	operating_30	0
2026-09-20 23:00:00.000000	PJM RTO Reserve Zone	primary_reserve	60.21
2026-09-20 23:00:00.000000	PJM RTO Reserve Zone	spin	60.21
2026-09-20 23:00:00.000000	Mid-Atlantic/Dominion Reserve Subzone	primary_reserve	60.21
2026-09-20 22:00:00.000000	Mid-Atlantic/Dominion Reserve Subzone	spin	32.07
2026-09-20 22:00:00.000000	PJM RTO Reserve Zone	primary_reserve	0
2026-09-20 22:00:00.000000	PJM RTO Reserve Zone	spin	32.07
2026-09-20 22:00:00.000000	PJM RTO Reserve Zone	operating_30	0
2026-09-20 22:00:00.000000	Mid-Atlantic/Dominion Reserve Subzone	primary_reserve	0
2026-09-20 21:00:00.000000	PJM RTO Reserve Zone	operating_30	0
2026-09-20 21:00:00.000000	PJM RTO Reserve Zone	primary_reserve	23.87
2026-09-20 21:00:00.000000	PJM RTO Reserve Zone	spin	23.87
2026-09-20 21:00:00.000000	Mid-Atlantic/Dominion Reserve Subzone	spin	23.87
2026-09-20 21:00:00.000000	Mid-Atlantic/Dominion Reserve Subzone	primary_reserve	23.87

Coverage

100.0% complete0 gap days1,452 days with data

Show coverage history

Coverage: 100.0%Days with data: 1,452Gaps: 0

2026

2025

2024

2023

2022

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Related ancillary services data

Related ancillary services data
Dataset	Description
Regulation PricesPJM · hourly	PJM hourly regulation results by area, including market clearing price, capability clearing price, cleared regulation quantity, and regulation requirement. These are different measures and must not be added together. Source: PJM Market Data.
Ancillary Service Market Clearing PricesSPP · 5-minute (RTBM) and hourly (Day-Ahead)	Cleared ancillary-service prices by SPP reserve zone for both the real-time balancing market and the day-ahead market. SPP's product set does not map onto other ISOs': regulation clears as a separate service (capacity) price and mileage price in each direction (reg_up_service, reg_up_mile, reg_dn_service, reg_dn_mile), alongside ramp up and down, spinning, supplemental, and uncertainty products. IMPORTANT: reserve_zone mixes two grains. It carries the numeric ancillary reserve zones (1 through 5 under the SPP balancing authority, 21 under the separate SWPW balancing authority) AND the two balancing-authority roll-ups, 'SPP' and 'SWPW', whose prices equal those of their member zones. Aggregating across every value of reserve_zone double-counts the market.
Ancillary Service PricesERCOT · hourly (DAM)	Hourly market clearing prices for the ancillary services ERCOT procures alongside energy in its Day-Ahead Market, broken out by product: Regulation Up (RegUp), Regulation Down (RegDown), Responsive Reserve (RRS), Non-Spinning Reserve (NSPIN), and the ERCOT Contingency Reserve Service (ECRS). These prices represent what the grid pays per megawatt to hold capacity in reserve for frequency control and contingency response, separate from the energy itself. Watching them shows when reserves are scarce and expensive (often during tight or volatile conditions), which informs how generators and storage operators allocate capacity between energy and reserve markets, and gives researchers a read on the cost of keeping the Texas grid reliable. ECRS, added in 2023, is the newest of these products and has at times cleared at notably high levels.
Ancillary-Service Clearing PricesCAISO · hourly	CAISO ancillary-service market clearing prices by delivery hour, market run, region, and product. Despite the legacy column name mw_or_price, values in this table are prices in USD/MWh; zero is a valid clearing price.