Issue 109 ‘Treatment of domestic solar self-consumption within Settlement’

Domestic customers with solar PV installations encounter challenges with the Boundary Point Settlement metering system. This system measures electricity import and export instantaneously, but it’s essential to understand that the examples provided aren’t based on specific moments but span an entire Settlement Period. While Half Hourly meters net values instantaneously, they don’t over a 30-minute duration, allowing for both Import and Export within the same half-hour. This distinction has led to potential discrepancies in energy billing and management.

The proposed solution aims to determine a customer’s Import and Export volumes based on the total energy generated and consumed across the entire Settlement Period, without focusing on the exact timing of these events. The introduction of the term ‘Reflux’ represents the netted energy exchanged between a home and the main electricity system within this period. A critical aspect of the discussion is analysing the costs associated with ‘Reflux’ energy to comprehend the relevant system charges. The Issue Group’s primary goal is to understand the impacts of this system, such as on Use of System charging, and to explore better alternatives, like those in CVA. The discussion will also consider which market segments are affected and how to best address their needs.

The first Issue 109 Workgroup meeting was held on Friday 3 November 2023.

Issue 109 was raised on 8 September 2023.