Coupled Simulation

This page explains the working of the coupled simulation.

Bids

Annular performs a simulation based on the principles of the EPEX day-ahead market. A satellite model expresses its (flexible) demand by submitting bids to the market. These bids can be expressed as a table with the following structure:

exclusive_group_id	profile_block_id	sense	timestamp	quantity	acceptance_ratio	price
…	…	…	…	…	…

The column names are accessible through ALL_BID_COLUMNS.

Where

• sense indicates demand or supply bids. See the documentation for Sense.

• quantity is the amount requested to supply or demand. Needs to be non-negative.

• acceptance_ratio is the minimum acceptance ratio, and needs to be 1 in current versions.

• price is the supply or demand price.

Block bids are defined by (exclusive_group_id, profile_block_id, sense). Within block bid, price and acceptance_ratio need to be the same for all rows. For more information on the exclusive_group_id and profile_block_id columns, see the sections on Profile Block and Exclusive Group bid types below.

Bid types

Annular currently supports the following bid types, as introduced on the EPEX website:

Profile Blocks

Classic block orders encompass several hours at the same price with flexible volume profiles and are executed at the same ratio on all its hours.

Each row in the bids table only specifies a bid for a single timestamp. Since bids for single timestamps are independent by default, such bids do not support any behavior with temporal dependencies.

Profile blocks are a solution to this: a multi-timestamp profile of demand or supply bids can be submitted to be executed in an All-or-None manner. All bid rows that share a profile_block_id will be treated as a single profile and will therefore be executed together.

Important

A profile may only contain one bid per timestamp per sense.

Note

Reusing Profile block IDs When using an exclusive group, all IDs for the Profile blocks are only used within that exclusive group. This means that the same profile_block_id can be used multiple times, as long as they are in different exclusive groups.

Exclusive Groups

Exclusive blocks: group of blocks within which a maximum of one block can be executed, so your electricity is traded at the most profitable moment

An exclusive group of blocks is specified when bids in the table share the same exclusive_group_id. Within an exclusive group, at most one profile will be accepted. By itself, an exclusive group gives no guarantee that any of its profile blocks are actually accepted.

Looped Blocks

Loop blocks: families of two blocks which are executed or rejected together. They allow to bundle buy and sell blocks to reflect storage activities.

In annular, only demand and supply bids/blocks can be ‘looped’ together. To do so, they must share the same profile_block_id and exclusive_group_id.

Note

Acceptance guarantees A demand bid/block at ceiling price that is looped with a supply bid/block is no longer guaranteed to be accepted. Since both the demand and supply side must be executed simultaneously, if the supply side cannot be executed, it will prevent the demand side from being executed too.

Curtailable Blocks

Curtailable blocks: set of blocks which can be either entirely executed or entirely rejected (All-or-None); or executed above a minimum acceptance ratio defined by traders.

Although the bids table specification already includes a column acceptance_ratio, curtailable blocks are not yet supported. All bids must use a value of 1 in the acceptance_ratio column, and will be executed on an All-or-None basis.

Not Implemented

Linked Blocks and Exclusive Links are currently not supported by annular.

Example

This example illustrates a valid bid:

exclusive_group_id	profile_block_id	sense	timestamp	quantity	acceptance_ratio	price
1	1	1	0	30	1	30
1	1	1	1	10	1	30
1	1	1	2	50	1	30
1	1	-1	5	9	1	14
1	1	-1	6	8	1	14

There are two profiles, a demand profile for the first 3 hours at a price of 30, and a supply profile at hours 5 and 6 for a price of 14. Because they have the same profile_block_id, they are either rejected or accepted together.