P407 ‘Project MARI’

Formal title: Project MARI

The Manually Activated Reserve Initiative (MARI) is the pan-European project to deliver a platform for manually-activated Frequency Restoration Reserve (mFRR) as per Article 20 of the European Balancing Guideline (EBGL). P407 represents the changes to the BSC that are part of the joint BSCCo/National Grid ESO (NGESO) work to enable GB participants to use the platform as well as providing a further balancing product for NGESO.

While there are some similarities to TERRE in that both MARI and TERRE are European balancing products, MARI is a balancing product in it’s own right and should not be considered as being ‘like TERRE’. 

Article 20 of the EBGL (Commission Regulation (EU) 2017/2195) requires Transmission System Operators (TSOs) to establish a platform for the exchange of balancing energy from manually activated frequency restoration reserves (mFRR) by July 2022. To achieve this, the European Network of Transmission System Operators for Electricity (ENTSO-E) launched the Manually Activated Reserves Initiative (MARI) to deliver the European wide mFRR platform. P407 will ensure that the BSC, and associated systems, are amended ahead of go-live.

NGESO raised P407 on 4 May 2020. P407 will run alongside a similar Modification Proposal for the Grid Code. The two Modifications will run together to enable GB market participants to participate in the mFRR platform.

Next Steps

The equivalent Grid Code Modification will be presented to the Grid Code Review Panel on 28 May 2020, which means the first cross-Code Workgroup meeting will be week commencing 22 June 2020, following Grid Code’s three-week period to nominate Workgroup members post Panel.

Current Status

Initial Written Assessment
Assessment Procedure
Report Phase
With Authority
Awaiting Implementation


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.

List of ELEXON insights

ELEXON Circulars

Training services delivered by ELEXON

Market Entry

Charge Codes and Switch Regimes

Add New