This page details all the relevant data that is available to the industry for the determination of Transmission Loss Factors (TLFs).
The information is in response to Modification P350 ‘Introduction of a seasonal Zonal Transmission Losses scheme’ which introduces a Transmission Loss Factor (TLF) for each TLF Zone and BSC Season.
Implementation
Data available
Accessing the TLF data
The ELEXON Portal is where ELEXON uploads the associated data.
- Portal site structure: Operational Data > TLFs determination
Current data
Data files include:
- Reference Network Mapping Statement (NMS)
- Load Periods (LPs) and Sample Settlement Periods (SSPs)
- Metered Volumes for Sample Settlement Periods
- Transmission Network Data
- HVDC Metered Volume Data for Sample Settlement Periods
- Distribution Network Data
- Total Delivering and Offtaking Metered Volume Data
- Nodal TLFs
- Adjusted Seasonal Zonal TLF (ATLFZs)
- BM Unit Specific TLFs
- Seasonal Zonal TLF (TLFZs)
- Transmission Loss Factor Adjustment (TLFAs)
- Indicative values of TLMij, for every Settlement Period in the Reference Year with TLFij=0
- Indicative values of TLMij, for every Settlement Period in the Reference Year with TLFij≠0
- Adjusted Nodal Power Flows
- Branch Power Flows
- Absolute Nodal Power Flows
Upcoming data timeline
The timeline below shows data files published, or due to be published, for the upcoming BSC Year 2020/21.
By 31 August 2019
- Imbalance Settlement Group (ISG) Decision on LPs/SSPs and methodology
- Actual LPs/SSPs
- Proposed Reference NMS and methodology
By 19 October 2019
- Approved Reference NMS
By 31 December 2019
- All remaining relevant files
