Day-Ahead Market include a trading process. In this process a has been complete in 6 different steps are as follow:

  • Bidding
  • Calculation
  • Transmission corridor Availability
  • Result
  • Confirmation
  • Scheduling

These are the steps that day-ahead market includes that we will describe in brief here.

• BIDDING :
The buyers and sellers submit their bids anonymously for sale or purchase of power for delivery on the following day. (T+1 day)
They Bids for total of 96 blocks of 15-minute each can entered.
The biding session start from 10:00 hrs. to 12:00hrs. Bids can be single n and/or block including linked bids.

Single bids: In single bids are 15-mintue bids for different price and quantity pairs can be entered through this type of order. Partial execution of the bids entered is possible.

Block bids: Relational Block Bid for any 15-min block or series of 15-min blocks during the same day can be entered. Although no partial execution is possible i.e. either the entire order will be selected or rejected.

The bids are entered during bidding session are stored in central order book. The bids entered during this phase can be revised or cancelled till end of bid call period i.e. 1200hrs. of trading day

• MATCHING :
After bidding process next step in process come matching. At the end of the bidding session, bids for each 15-mintue time block are matched using the price calculation algorithm. (available in IEX bye-laws)
All purchase bids and sale offers are aggregated in the unconstrained scenario. The aggregate supply and demand curves are drawn on Price-Quantity axes. The intersection point of the two curves gives the market clearing price (MCP) and market clearing volume (MCV) corresponding to price and quantity of the intersection point.
MCP and MCV are determined for each block of 15-min as a function of demand and supply which is common for selected buyers and sellers.
Selected members are intimated about their partially or fully executed bids and other trade related information. After this calculation hour transmission corridor required to fulfill successful transactions are sent to NLDC.

• Transmission corridor Availability :
Preliminary MCP and MCV are used to calculate the provisional obligation of the selected participants and the provisional power flow. Funds are available in the settlement accounts of the participants are verified based on the provisional obligation. In case of insufficient funds in the account, the bids entered by that participants are deleted.
Required corridor capacity and provisional power flow sent to NLDC for scrutiny and corridor allocation is requisitioned based on availability. By 1400hrs. NLDC reverts with actual transmission corridor availability during all 15-min time blocks across congestion prone bid areas.

• RESULTS :
Based on the reserved transmission capacity intimated by NLDC, IEX recalculates MCP and MCV as well as area clearing price (ACP) and area clearing volume(ACV).
ACP used for the settlement of the contracts. On receipt of final results, obligations are sent to the clearing banks for pay in from buying members at 14:30hrs. and the bank is asked to confirm the same.

• CONFIRMATION & SCHEDULING :
After result step next step is confirmation and scheduling step. In confirmation step schedule is confirmed by NLDC. Then After that finally schedule to RLDC’s.