Day-Ahead Market

The Day-Ahead Market (DAM) is a voluntary, financially-binding forward energy market. The DAM matches willing buyers and sellers, subject to network security and other constraints, whereby energy is co-optimized with Ancillary Services and certain Congestion Revenue Rights. It provides a platform to hedge congestion costs in the day-ahead of the Operating Day, and instruments to mitigate the risk of price volatility in Real-Time.

Ancillary Service Plans
DAM Ancillary Service Plan View Ancillary Service requirements for each hour of the current and next day.
Percent Change in Load-Provided Responsive Reserve View the total amount of Responsive Reserve Service (RRS) allowed by Load Resources.

Day-Ahead Market Results Displays
DAM Clearing Prices for Capacity Display View the Market Clearing Prices for Capacity for all Ancillary Services for the next day, current day, and previous five days.
DAM Settlement Point Prices Display View the DAM Settlement Point Prices for all Trading Hubs and Load Zones for the next day, current day, and previous five days.

Day-Ahead Market Results Reports
Aggregated Ancillary Service Offer Curve View the aggregated Ancillary Service Offer Curve for the last 30 days on a daily basis which includes the following AS types: OFFNS, ONNS, REGDN, REGUP, RRSGN, RRSLD, & RRSNC.
DAM Clearing Prices for Capacity View the Market Clearing Prices for Capacity for all Ancillary Services from the Day-Ahead Market for the last thirty days on a daily basis.
DAM Hourly LMPs View the Hourly Locational Marginal Prices per electrical bus from the Day-Ahead Market for the last thirty days on a daily basis.
DAM Settlement Point Prices View the Settlement Point Prices for all Resource Nodes, Load Zones, and Trading Hubs from the Day-Ahead Market for the last thirty days on a daily basis.
DAM Shadow Prices View active and binding constraints as well as the associated shadow prices from the Day-Ahead Market for the last thirty days on a daily basis.
DAM Total Energy Purchased View the total amount of energy purchased via valid energy bids per Settlement Point from the Day-Ahead Market for the last thirty days on a daily basis.
DAM Total Energy Sold View the total amount of energy sold via three-part supply offers, energy offer curves, and energy-only offers per Settlement Point from the Day-Ahead Market for the last thirty days on a daily basis.
DAM PTP Obligation and Option Results by Settlement Point View the total amount of PTP Obligation Bids awarded and CRR Offers not awarded in the Day-Ahead Market per Settlement Point where the Settlement Point of the bid or offer is either the Source or the Sink for the last thirty days on a daily basis.
Day Ahead Point-to-Point Option Price Report View the Point-to-Point Option price in dollars identified by Source & Sink Settlement Point calculated by MMS from the Day-Ahead Market for the last thirty days on a daily basis.
Total Ancillary Service Offers View the total quantity in MW of Offers per Ancillary Service per hour from the Day-Ahead Market for the last thirty days on a daily basis which includes the following AS types: REGDN, REGUP, RRS, & NSPIN.
DAM Electrically Similar Settlement Points View the current list of all DAM Electrically Similar Settlement Points (ESSPs) that are used for market processes and transactions. Per protocols, certain transaction are not allowed between ESSPs. In order to support this protocol requirement, a list of ESSPs are posted prior to 0600 as a study for DAM, and also after DAM completion to reflect the ESSP list that was enforced in the DAM solution (recognizing that the network topology and outage changes can add or remove settlement points from the ESSP list on an intra-day basis).
DAM De-Energized Settlement Points in Base Case View the list of settlement points that were de-energized in the base case of the Day Ahead Market.

Day-Ahead Supporting Information
Electrical Bus Mapping for Heuristic Pricing This report shows the heuristic pricing associations on a daily basis that are used in the market solutions for Day-Ahead Market (DAM) and Real-Time Market (RTM). This posting helps the market's understanding of the methodology and values of the published prices.
Load Forecast Distribution Factors View hourly estimates of each load’s proportion of its load zone forecasted value for an entire week.
Settlement Points List and Electrical Buses Mapping View the current list of all Settlement Points that may be used for market processes and transactions.

System Conditions
Actual and Forecasted Regional Wind Production View actual wind-powered production for the last 48 hours and forecasts for the next 48 hours.
Weather Assumptions View forecasted hourly temperature values for the next day for each weather zone.

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Key documents

Methodologies for Determining Ancillary Service Requirements
Find the methodology used to determine the minimum monthly Ancillary Service requirements.
(04/09/13, .zip, 103.5 KB)
Load Distribution Factors Methodology
This methodology describes the TAC approved steps needed to generate and maintain Load Distribution Factors (LDF).
(01/07/13, .doc, 64 KB)
Procedures for Setting Nodal DAM Credit Requirement Parameter
The Procedures for Setting Nodal Day Ahead Market (DAM) Credit Requirement Parameters are approved by the ERCOT Board of Directors and define the credit exposure requirements used during the DAM as required by Protocol Section 4.4.10.
(10/01/12, .doc, 41 KB)