P407 ‘Project MARI’

Formal title: Project MARI (Manually Activated Reserve Initiative)

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.

Project MARI webinar


Next Steps

Following the end of the Brexit Implementation Period on 31 December 2020 there is no longer an obligation to comply with Article 20 of the EBGL as this particular article was not retained into UK law. Similarly, there is nothing in the UK/EU Trade and Cooperation Agreement (TCA) that allows for GB’s participation in the mFRR process. As a result, the defects of this Modification no longer exist and unless a new agreement is reached between the UK and the EU, participation in MARI will not be possible. Following discussion with Ofgem, NGESO has therefore withdrawn support of P407.

There may be a requirement for MARI (or a similar product) in the future – this could be a regulatory or operational requirement. If this is the case, new Modifications will be raised and the work that has been completed to date can be repurposed. Our work so far will soon be available on this webpage.

Notice of Modification Withdrawal was sent 10 February 2021 and P407 will officially close at 12:00 on Thursday, 18 February 2021, unless adopted.

No notices were received by 12:00 on Thursday, 18 February 2021 and P407 was officially closed.

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If you have any problems or issues downloading or accessing any of the supporting documents on this page then please contact the highlighted Lead Analyst. Workgroup materials can be found in the Assessment Procedure section below.

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Assessment Procedure


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