The wholesale information system manager runs the wholesale information and trading system (WITS) used for the 24/7 buying and selling of spot market electricity.
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About the WITS manager
The wholesale information system manager runs the online wholesale information and trading system (WITS).
The WITS acts as a central facility for the receipt and publication of information between, and on behalf of, buyers and sellers in the wholesale electricity market.
The WITS keeps track of wholesale electricity bids and offers 24/7. It publishes real-time pricing information every 5 minutes, as well as the final bids and offers.
Why is this role important?
Electricity sellers and buyers send their bids and offers for energy and reserves to WITS. Bids and offers can be revised up to the start of the next 30-minute trading period.
Bids and offers form part of the supply and demand data required by the system operator to forecast the scheduling of electricity generation and reserves. Schedules are published every half an hour.
When the system operator dispatches generation (usually every five minutes), the resulting prices are sent to the clearing manager and are published on WITS. At the end of each 30 minute trading period, the clearing manager calculates the price for the trading period using these dispatch prices. These are published on WITS as interim prices and are republished at 2.00pm the next day as final prices, allowing time for participants to make a price error claim if the calculation process is incorrect.
The clearing manager sends constrained on/off amounts and block settlement differences to WITS for publication to the market. It also sends invoices to WITS for distribution to participants.
WITS sends compliance information to the Electricity Authority to monitor that participants are adhering to the Code.
Section 13 of the Code requires that the WITS has backup arrangements for alternative submission and publication mechanisms in case of any disruption to the WITS system.
Who is the WITS manager?
The Electricity Authority has contracted NZX as the WITS manager.
Monthly reports are available below on the WITS function. These include service levels against targets, fault response and resolution times.
Service provider agreements
The service provider agreements set out the functions and processes that the WITS manager must perform.