CIM
Common Information Model
IEC 61968/61970 data model for power system assets, topology and limits. Underpins LTDS.
Digital
If the physical layer is pipes and wires, the digital layer is everything that tells an operator what is happening inside them. CIM describes assets. LTDS publishes network models. BMRS streams real-time market data. DIP routes MHHS messages. DCC moves smart-meter readings. This route is the reference map.
17Route 17 · FoundationsAfter this route you will be able to
21 March 2024MHHS Update 38 · programme slips 12 months
Market-wide Half-Hourly Settlement is the biggest digital-layer reform of the 2020s. Every GB meter moves to settlement at 30-minute granularity. The change requires coordinated release across suppliers, DNOs, DCC, Elexon, and the new Data Integration Platform. In
The reason was not technology. Smart meters were in the ground. Settlement IT was built. The physical layer was ready. What slipped was data readiness: 60 organisations needed to agree on schemas, test interface behaviour under load, and redevelop consumer-side processing for half-hourly volumes. The hard part of digital-layer reform is not the code. It is the data.
The MHHS delay is a preview of every future digital-layer reform. Governance can set direction. Physical assets can be installed. But until the data flow through the seven industry codes and the dozen core systems is verified, integrated and tested, the reform is not real.
The digital layer is where GB energy reform lives or dies. What are the systems, what do they carry, and where do they interlock?
The answer is a small set of named systems. Each has a purpose. Each has a standard. Most interlock with at least one other.
Section 01 · The ten systems
Each of the systems below is a necessary part of the 2026 digital landscape. Understanding which function each delivers is the quickest route to reading any GB reform announcement.
CIM
IEC 61968/61970 data model for power system assets, topology and limits. Underpins LTDS.
LTDS
Annual DNO network data in CIM. v2-1-0 uses EQ v7, SCR v3, SYSCAP v5, Header profiles. SHACL-validated.
BMRS
Half-hourly GB balancing, generation, demand, price data. Free and open.
DIP
Hub-and-spoke message routing for MHHS. Replaces bilateral integration across suppliers and DNOs.
DCC
Smart-meter comms network. Moves ~2.7 bn readings/day between meters and suppliers.
SCADA
Real-time transmission and distribution telemetry. Sub-second sampling for operational control.
BSC IT
Settlement engine for GB electricity. Reconciles metered energy against contracted at half-hourly granularity.
Carbon API
30-minute grid carbon intensity with regional breakdown. Public and free. 48-hour forecast horizon.
FES
NESO's annual planning scenarios. Inputs to strategic decisions at DESNZ, Ofgem, investors.
Capacity reg.
Register of contracted capacity, auction results, delivery milestones. Transparency feed.
Not exhaustive but covers the core of any 2026 conversation about GB energy data. The seven industry codes (BSC, Grid Code, CUSC, DCUSA, STC, UNC, SEC) govern interactions between these systems.
Section 02 · The standards
The digital layer is held together by standards. Understanding which standard governs which system is the minimum literacy for reform analysis.
IEC 61968 / 61970 (CIM family). The canonical power-system data model. CIM describes how an asset, a topology or a limit is represented so multiple parties can share the same picture. LTDS is a CIM profile that GB DNOs publish annually.
SHACL. A W3C standard for validating RDF data against shape constraints. LTDS uses SHACL to check that submitted data meets the profile's structural requirements. The LTDS validator tool is a SHACL engine with the Ofgem profiles loaded.
BSC. The Balancing and Settlement Code. Defines metering, settlement, imbalance prices. Any new tariff or new settlement arrangement touches the BSC. MHHS is a BSC-anchored reform.
ISO 27001 and UK GDPR. Information security and personal-data protection. Half-hourly consumption is personal data under UK GDPR; the Smart Energy Code adds sector-specific rules on top.
Data submitted under the Long Term Development Statement must conform to the published CIM profile for the relevant release version. Non-conforming submissions shall be rejected and returned for correction.
Ofgem LTDS data submission requirements (Distribution Licence Standard Condition 25)
Section 03 · Data quality incident
A SCADA reading shows 420 MW at a 132 kV substation. The settlement engine records 405 MW. Which layer investigates first?
Check your understanding
Real-time balancing and market data.
Primary real-time data reference.
30-minute GB carbon intensity.
Primary API reference.
MHHS governance, timeline, DIP specification.
Primary reform reference.
DNO annual network data publication.
Regulatory source.
Personal data treatment rules.
Privacy regulator.
Continue with the operating model. How the institutions in the governance layer coordinate the physical and digital.