The Enduring Auction Capability (EAC), National Grid ESO’s new, in-house platform for procuring frequency response and reserve services, will be launched in October. The EAC will completely change how providers bid for frequency response services.
This article outlines all the new elements to consider for placing bids following its launch.
For a quick summary of what the EAC will bring, read our piece from earlier in the year here.
Want to know what this looks like in practice? Head to our latest deep dive to learn how to turn baskets and substitutable child orders into actual bids for frequency response contracts.
Baskets are key to bidding in the Enduring Auction Capability
In the EAC, bids for contracts will be submitted through baskets.
Baskets are grouped sell orders for a single unit, in a single service type, and over a single service window. “Service type” means one of frequency response (the entire dynamic suite), Quick Reserve, or Slow Reserve. “Service window” refers to the different contracting windows - for frequency response, this is by EFA blocks.
For frequency response, a basket can contain orders in both directions across all three dynamic frequency response services for one EFA block.
When multiple baskets are submitted for one EFA block, these are mutually exclusive with each other.
Although baskets can only be for a single EFA block, they can be connected with another basket from another EFA block. This is called a looped family. Multiple looped family bids for the same blocks are mutually exclusive.
Providers will be able to submit up to 25 baskets, per unit, per day.
Baskets are made up of different orders: parent orders (one per basket), child orders (up to ten per basket), and substitutable child orders (up to ten per basket). Each order can include volume across multiple frequency response services but at one price.
Each of these order types is described in more detail below.
Order types in the EAC
Parent orders
A parent order is non-curtailable and must be accepted in full. Each basket must contain exactly one parent order. In the EAC, a parent order can now be submitted with a volume of 0 MW.
Child orders
A child order is curtailable and may be partially accepted. It can only be accepted if the parent order within the basket is accepted. If a child order includes volume across multiple services, these must all be accepted for the same proportion if curtailed.
Up to 10 child orders can be included within each basket, and multiple child orders can be accepted, each assessed on its own merits. Each accepted child order will stack on top of any others accepted.
Substitutable child orders
A substitutable child order is curtailable and may be partially accepted. These are new to the EAC.
Up to 10 substitutable child orders can be included within each basket, and multiple can be accepted. But in contrast to child orders, substitutable child orders are accepted in relation to each other.
This is achieved by something called the “acceptance ratio”. For each substitutable child order, this is defined as the accepted volume divided by the bid volume. The sum of acceptance ratios for all accepted substitutable child orders in a basket cannot exceed 1.
Want to find out more? Modo Plus and Enterprise users can read our latest Deep Dive - to find out what new bidding strategies will likely emerge when the EAC launches.