The Day-Ahead Energy Market (DAM) is a financial market where market participants purchase and sell energy at financially binding day-ahead prices for the following day. The DAM is the financially binding schedule of commitments for the purchase and sale of energy that is developed by ISO New England each day based on the bid and offer data submitted to the DAM by the market participants. A supply offer or a demand bid will clear the DAM if its associated price is less than or equal to the hourly Locational Marginal Price (LMP) at its location, as system conditions allow.

The DAM allows buyers and sellers to lock in their price and hedge against volatility in the Real-Time Energy Market.

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ISO New England has three primary responsibilities to maintain reliability throughout the region:

• Manage New England's marketplace to ensure a fair and reasonable marketplace
• Develop Manage long-term planning process in New England
• ISO-NE uses a security-constrained economic energy dispatch model to dispatch generators based on the least production cost basis that considers many variables, including generation offers and congestion impacts on Locational Marginal Pricing (LMP)

The Unit Commitment takes into account all of the costs of producing the energy, including no-load costs and start-up costs. At the same time, it respects each resource's characteristics such as minimum up time, minimum down time.

• Parameters Used in Unit Commitment
• Incremental Energy Offer Curves
• Start-up Costs $ (Hot, Cold, Intermediate)
• Costs incurred per startup of the resource
• Type of start is based upon number of hours down since previous run
• No-Load Costs $
• Fixed cost that is incurred every hour the resource is running
• Minimum Run Time (in hours or fractions of hours)
• Minimum Down Time (in hours or fractions of hours)
• Economic Minimum and Economic Maximum

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The hourly clearing in the DAM describes the hours of commitment for real time. Real time dispatch of capability above the EcoMin to the EcoMax is performed based on economics. Participants have the option of declaring a self-schedule to ensure a minimum level of operation in amounts cleared in the DAM.

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The DAM commits resources with the goal of minimizing total production cost for the New England Control Area. Therefore, there may be a number of reasons why a unit was not committed: the start-up and no-load costs cause an increase in total production costs.

The resource may have been in merit for a few of the hours, but due to its minimum run time it was not in-rate for additional hours. As a result, commitment for the whole of the unit's minimum run time causes total production costs to increase.

The commitment of the unit may aggravate a transmission constraint that causes an increase in total production costs.

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Self-schedules are always committed at their EcoMin and dispatched up to EcoMax if economical. (Review the unit in eMarket application - Bids and Offers located in the tab titled Generation).

NOTE: eMarket Hierarchy for Generation ALWAYS looks at unit hourly updates first, if nothing there, it defaults to Schedule Detail and if nothing there, defaults to Unit Manager.

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The dispatching software has committed your unit on because of reliability issues.

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Demand schedules for dispatchable loads are only used in the DAM for establishing a day-ahead financial commitment at that asset's node. These schedules are not used in real-time operation. In order to ensure that a dispatchable load that is scheduled in the DAM will run, it must be self-scheduled in the Real-Time (Balancing) Market.

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A generator committed economically by the DAM can clear to a value no greater than the larger of:  60 X MRR (Manual Response Rate) or EcoMin.

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A non-dispatchable asset can offer in the Day-Ahead Energy Market and will be settled at the nodal price.

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