BSC Insights: Imbalance Prices with new CADL and DMAT


Emma Tribe’s insight article highlights the potential impact of changes to the De Minimis Acceptance Threshold and the Continuous Acceptance Duration Limit which take effect on 1 April 2019. The article explains the changes and includes interactive graphs to illustrate how these changes might affect Imbalance Prices.

Published: March 2019

What are the changes?

The changes to these parameters are:

  • The De-Minimis Acceptance Threshold (DMAT) to reduce from 1MWh to 0.1MWh
  • The Continuous Acceptance Duration Limit (CADL) to change from 15 minutes to 10 minutes

These changes will improve the tagging and flagging processes used to determine the Imbalance Price.

Impact on Imbalance Prices

We have recalculated Imbalance Prices since 1 January 2019 with the new parameters (CADL 10, DMAT 0.1), and compared these prices to the live Imbalance Price (CADL 15, DMAT 1).

Average Imbalance Price

This graph shows the average Imbalance Price calculated using the live parameters (CADL 15, DMAT 1) and the future parameters (CADL 10, DMAT 0.1).

From 1 January 2019 to 3 March 2019 the:

  • The average Imbalance Price (£/MWh) is 50.74 -CAD 15, DMAT 10
  • The average Imbalance Price (£/MWh) is 50.51 -CAD 10, DMAT 0.1
  • Average price difference (£/MWh) is -0.23

Graph: Average Imbalance Price (details above)

Maximum changes in Imbalance Price

This graph looks at the differences between the Imbalance Prices calculated with the live parameters (CADL 15, DMAT 1) and the future parameters (CADL 10, DMAT 0.1).

Maximum Price increase (£/MWh) 25.00.

Minimum Price Decrease (£/MWh) -40.25.

Graph: Maximum changes in Imbalance Price (details abvoe)

Percentages of flagged and tagged actions

These graphs demonstrate how the parameter changes will cause fewer actions to be CADL Flagged and DMAT Tagged, as part of the Imbalance Price calculation.

Graph: Maximum changes in Imbalance Price (details abvoe)

Interrogate our data

We haven’t included detailed analysis in this article because the graphs are updated automatically every day and any analysis would soon become invalid. However, there are cards on the graphs that give a brief summary and there are lots of sliders and filters to help you undertake your own analysis.

By default, the graphs are displayed by Settlement Day. However, the data can be displayed by half-hourly Settlement Period by clicking ‘Go to the next level in the hierarchy’ in the top left hand corner of the graph.

Alternatively, by enabling the ‘Click to turn on Drill Down’ on the top right hand corner of the graph, you can drill down into data by clicking on a data point.

You can also adjust the date range shown in the graph by using the Settlement Date range slider. You can select the system length to look at daily average prices when the system is long or short.

In the final graph, the action direction (i.e. whether the accepted action was in the buy stack or sell stack) can be specified using the action direction filter.


Click on the X next to any of the icons to replace them with a short-cut link to the page you are currently on or search for a specific page.