Day Ahead Constraint Flows and Limits

The data below is a snapshot of the limits and flows at relevant boundaries at day ahead stage. These flow values are calculated at Day Ahead and will not reflect any changes in the flows following the publication of this data. The boundary flows are the forecast position after Day Ahead energy scheduling has been run.

Please note that from the 22nd April 2024 the flows no longer consider expected constraint mitigation or optimisation actions. Before this date the data did consider constraint mitigation actions. This change has happened as the software used to collate this information has been updated.

Please Note: The data for the SSEN-S boundary is currently unavailable.

The network diagrams show the constraint boundaries and arrows indicating the positive direction of power flow across each boundary.

Data Explorer

Data Explorer

Table Information

Constraint Group

Title Constraint Group
Type string
Description The geographical area in which the constraint occurred. Each group has its own unique code, which relates to the network diagram linked above. The ten most important boundaries are included in this data file.
Example ESTEX

Date (GMT/BST)

Title Date (GMT/BST)
Type datetime
Description The date and time for the given limit and flow through the constraint boundary. This is given in a MM/DD/YYYY HH:MM format. The flow and limit for each constraint group is given for a day, before moving onto the next day. Data is given on a settlement period (half hourly) basis.
Example 2019-01-10T03:30:00

Limit (MW)

Title Limit (MW)
Type integer
Description The maximum amount of power that can flow through a constraint boundary.
Example 5450
Unit MW

Flow (MW)

Title Flow
Type number
Description A snapshot of the power flows across a number of important constraint boundaries at day ahead. This power flow forecast is created based on the next day’s wind forecast, generation dispatch and demand forecast and is modelled using power system software.