Visibility issues at the boundary point led to the P375 Balancing and Settlement Code (BSC) modification P375 being raised last year, with administrator Elexon looking to go "one step beyond" previous modifications to allow individual asset meters to be used for settlement purposes.
This modification brings in multi-use, more complex sites that would have likely been excluded or used on a limited basis, and offers access to the Balancing Mechanism (BM) for smaller players, explained Elexon’s metering manager Iain Nicoll speaking in the first of the Current± Briefings webinar series today.
The modification goes back to Project TERRE, a Europe-wide programme designed to establish a new replacement reserve balancing product in participating countries, which included plans for wider access of the BM through the P344 modification, raised to align the BSC with TERRE requirements.
Prior to P344, in order to participate in the BM sites were required to be registered as a central volume allocation, with these sites now referred to as Primary BM Units. P344 saw the introduction of Secondary BM Units, which used the supplier volume registered boundary point metering systems.
The modification allowed virtual lead parties - participants providing Secondary BM Units - to aggregate a number of Meter Point Administration Numbers (MPANs) to participate in the BM. However, the workgroup involved in the solution for that raised an issue with balancing service being delivered, but not being visible, at the boundary point.
Nicoll offered the example of a pump/compressor delivering a balancing service by reducing import by 2MW, with a process starting on another part of the site using 1.5MW at the same time. This would lead the Boundary Meter to only show 0.5MW delivered.
This resulted in issue group 70, which recommended the raising of modification P375 that will use metering behind the boundary point to settle on Secondary BM Units.
“Rather than having an MPAN for it, you would have an asset metering system identifier and you would pair that up with a boundary point MPAN to identify the connection between the asset and the site boundary point,” Nicoll said.
When it comes to exploring the specific metering equipment, Nicoll explained that one thing Elexon looked at was requiring an approved half hourly meter, however “this would have made it not viable for smaller players” with the half hourly metering solution based around industrial and commercial sites.
This then opened it up into using operational meters and non-BSC approved half hourly meters. The first two were approved by BSC standards, but Elexon “broadened it out into a third category that was particularly aimed at the smaller market where it was a metering device that was embedded with the product, so an electric vehicle (EV) charging unit or a small-scale battery storage unit”.
“It was a bit of a departure from what we would normally deal with,” Nicoll added.
EV charging firms were one of a variety of different players to be involved in the P375 working group, alongside suppliers, virtual lead parties, data aggregators and more.
The EV firms were “heavily involved in it” as a feature of Secondary BM Units is being able to aggregate a small number of components up to a secondary BM unit “to make something that’s of significant value in terms of MW”.
As it stands, the P375 modification was approved by Ofgem on 24 February 2021, with an expected implementation date of 30 June 2022.