Module 1 of 5 · Foundations

The big picture: why energy data matters

25 min read 3 outcomes Interactive quiz + 5 tensions diagram

By the end of this module you will be able to:

  • Explain what energy system data is using Ofgem's official definition
  • Describe the five key tensions shaping the GB energy data landscape
  • Name the scale of data generation across smart meters, SCADA, and market systems

1.1 What is energy system data?

Every time you switch on a light, boil a kettle, or charge your phone, a chain of events happens that you never see. Electricity is generated at a power station or wind farm, travels through high-voltage transmission lines, steps down through local distribution networks, and arrives at your home through your meter.

Alongside the electricity, there is an invisible river of data. Your smart meter records how much energy you use every 30 minutes. That data travels to the Data Communications Company (DCC), then onwards to your energy supplier so they can bill you, and to Elexon so the national electricity market can be settled correctly. A second river runs in parallel from substation SCADA telemetry to the network operator's planning systems and on into grid investment decisions. Both rivers depend on the same regulator and the same industry codes.

From physical asset to decision input: who handles GB energy data

Four-row map showing where the data originates, who governs the exchange, who consumes it, and which evidence record closes the loop.

Two journeys for GB energy data: consumer bills and network planning Four-region map. A red strip at the top names the regulator Ofgem and the Data Best Practice. Below it the consumer path runs left to right through four cards: smart meter at home, DCC WAN, Elexon settlement, supplier bill. A dashed rule separates the two paths. Below it the infrastructure path runs left to right through four cards: substation SCADA, DNO operational tech, DNO and NESO planning, grid investment. A red-bordered strip at the bottom names the industry codes that govern both paths. REGULATOR · OFGEM DATA BEST PRACTICE 8 Oct 2024 Decision CONSUMER PATH ASSET SMETS 2 Smart meter at home Half-hourly kWh reads CAPTURE SEC Schedule DCC WAN Authorised messaging FLOW BSC §Q Elexon settlement GSP, BMU, supplier DECISION REC Schedule Supplier bill Imbalance flows in INFRASTRUCTURE PATH ASSET DCUSA Substation SCADA 2-10 sec telemetry CAPTURE NCSC OT DNO operational tech Air-gapped OT network FLOW Grid Code DNO and NESO planning FES, SSEP, CSNP inputs DECISION RIIO-3 Grid investment Reinforce, defer, flex INDUSTRY CODES · BSC · SEC · REC · GRID CODE · DCUSA built by ransfordsnotes.com

The bill and the network plan both depend on the same regulated data flows. Source: Ofgem Data Best Practice Guidance, BSC, SEC, REC, Grid Code.

In everyday language, energy system data is any information created because energy is being generated, transported, or consumed. It includes everything from smart meter readings to the technical specifications of a transformer in a substation, from the price of electricity on the wholesale market to the geographic coordinates of an underground cable.

In the official regulatory world, the definition is precise. Ofgem, the energy regulator, changed it formally on 8 October 2024 so that the regulated scope is no longer limited to data needed for the operation of the system.

Energy System Data means any data relating to the energy system, whether produced by, for, or about the energy system.

Ofgem - Decision on Data Best Practice Guidance, 8 October 2024

The broader definition captures everything: meter readings, network models, market data, planning forecasts, asset registers, consumer consent records and innovation datasets. It replaced a narrower definition that only covered data necessary for the operation of the energy system.

Energy system data: the definition Ofgem broadened in October 2024

Side-by-side comparison of the data Ofgem covered under the Data Best Practice before October 2024 and the data covered after the definition was widened.

Ofgem's 2024 broadening of the Energy System Data definition Two parallel stacks. The left stack shows the narrow pre-2024 scope of Energy System Data: operational meter data, network operations and settlement reads, drawn with dashed borders. The right stack shows the broad post-October-2024 scope with the same three categories kept plus four new categories highlighted in red soft: planning data, consumer consent records, asset registers and innovation datasets. A brand-red band below states the decision date 8 October 2024. BEFORE · NARROW SCOPE Operational data only AFTER · BROAD SCOPE Produced by, for, or about Operational meter data DCC reads, telemetry Network operations SCADA, switching Settlement reads MHHS half hours out of scope before 2024 out of scope before 2024 out of scope before 2024 out of scope before 2024 Operational meter data DCC reads, telemetry Network operations SCADA, switching Settlement reads MHHS half hours Planning data Capacity scenarios, FES NEW Consumer consent records CCS, opt-in registers NEW Asset registers Substation, cable, transformer NEW Innovation datasets Network Innovation, SIF NEW KEPT KEPT KEPT DECISION · 8 OCTOBER 2024 Ofgem broadened the Energy System Data definition built by ransfordsnotes.com

Ofgem's 8 October 2024 decision moved planning data, consent records, asset registers and innovation datasets into scope. Source: Ofgem Decision on Data Best Practice Guidance.

The definition matters because it determines which data falls under Ofgem's Data Best Practice Guidance, the rules that govern how energy data must be managed. Under the old definition, many valuable datasets were outside scope. The new definition brings them all in.

Now that we have the official definition, the next question is scale. The numbers are larger than most people expect.

1.2 The scale you need to understand

Great Britain's energy system generates an extraordinary volume of data. Five scale indicators bound the engineering challenge:

  • 40 million smart meters each recording 48 readings per day produce 1.92 billion readings per day, roughly 700 billion per year. Under Market-wide Half-Hourly Settlement (MHHS, cutover July 2027), every one of these will flow through the entire settlement chain.
  • Thousands of SCADA-monitored substations, each sampled every 2 to 10 seconds, produce approximately 69 million data points per hour for a large DNO. This data flows over air-gapped Operational Technology networks, physically separated from the internet.
  • About 20 gas chromatographs at National Transmission System entry points continuously measure the exact calorific value of gas flowing into the national pipeline system, determining how every gas bill in GB is calculated.
  • 13 authoritative categories covering 87 distinct data types, each with a defined producer, consumer, governing instrument, and sensitivity classification.
  • Seven major industry codes (BSC, REC, SEC, Grid Code, DCUSA, CUSC, UNC), each governing specific aspects of data creation, flow, and use.

What the GB energy system produces every day, by the numbers

Five scale indicators that bound the engineering challenge: smart meter reads, SCADA points, gas chromatographs, authoritative data categories and industry codes.

Five scale indicators bound the GB energy data engineering challenge A vertical matrix of five rows. Each row pairs an indicator (smart meter reads, SCADA points, gas chromatographs, data categories, industry codes) with the headline number in a numeric pill, the unit and period of measurement, and the authoritative source. The smart meter reads row is emphasised because it dominates volume. INDICATOR HEADLINE NUMBER UNIT AND PERIOD SOURCE SCALE A Smart meter readings 1.92 bn PER UNIT per day across 40m meters SOURCE DESNZ Smart Meter Stats Q4 2025 SCALE B SCADA telemetry points ~69 m PER UNIT per hour, large DNO SOURCE DCUSA, licence SpC 9.5 SCALE C Gas chromatographs (NTS entry) ~20 PER UNIT continuous calorific value SOURCE Uniform Network Code §H SCALE D Authoritative data categories 13 PER UNIT covering 87 data types SOURCE Ofgem Data Best Practice SCALE E Industry codes touching data 7 PER UNIT BSC, SEC, REC, GC, more SOURCE Ofgem code registry built by ransfordsnotes.com

Sources: DESNZ smart meter statistics, MHHS programme, Ofgem Data Best Practice Guidance category list, and the seven industry codes registry.

Managing this volume reliably, securely, and accurately is one of the greatest data engineering challenges in UK infrastructure.

Licensees shall collect, manage and share data in accordance with the Data Best Practice Guidance published by the Authority, and shall publish a Digitalisation Strategy and Action Plan.

Ofgem - Distribution Licence Condition SpC 9.5

This licence condition makes data governance a regulated obligation for all distribution network operators, not a voluntary commitment. Non-compliance can trigger formal enforcement action by Ofgem.

Check your understanding

Why did Ofgem broaden the definition of 'energy system data' in October 2024?

Understanding the volume is one thing. Volume alone does not explain why energy data is genuinely difficult to govern. Five unresolved tensions shape every policy and technical decision in this landscape.

1.3 Five key tensions you need to know

The GB energy data landscape is defined by genuine, unresolved tensions. Understanding these helps a learner read every other module in this course in context. These are not academic debates. They affect how data flows, who can access it, and what happens to personal privacy.

Five unresolved tensions shaping GB energy data

Each tension is shown as a force pair. The arrows point at the legitimate goal on each side; the centre band names the policy or technical question left open.

Five force pairs that shape every GB energy data decision Five horizontal rows, each a tug-of-war between two legitimate goals. The left card names one side with its detail and citation. A central red-soft band states the tension title and the open question. The right card names the opposing side. Short arrows point outward from the centre toward each side card, showing equal-weight pull with no clean winner. The tensions are open vs secure, centralised vs federated, consent vs system need, innovation vs price control, national standard vs local variation. FIVE TENSIONS · EACH SIDE A LEGITIMATE GOAL TENSION 1 DBP GUIDANCE §2 Open by default Reuse and innovation OPEN vs SECURE Where does open data end and operational risk begin? NCSC OT GUIDANCE Restricted for security SCADA, network topology TENSION 2 ELHUB POLICY Centralised hub Norway's Elhub model CENTRALISED vs FEDERATED One hub, or five governed platforms with discovery? DSI (INTERIM) Federated platforms DCC, DIP, ETS, RECCo, NESO TENSION 3 UK GDPR ART 6 Individual consent Personal data baseline CONSENT vs SYSTEM NEED Is half-hourly settlement data consent-bound or BSC-bound? BSC §Q System obligation Settlement under BSC TENSION 4 DIGITALISATION REPORT Move at AI speed Twin, model, deploy INNOVATION vs PRICE CONTROL Can a 5-year RIIO cycle keep up with monthly model drift? OFGEM RIIO-3 SSMD 5-year price control RIIO-3, baseline funding TENSION 5 IEC 61970 Common model IEC 61970 CIM, CGMES NATIONAL STANDARD vs LOCAL VARIATION Will 14 DNOs converge on one schema, or remain mostly compatible? OFGEM LTDS DIRECTION DNO-specific schemas LTDS stages 1.3 to 3 built by ransfordsnotes.com

Each row shows two legitimate goals pulling against each other. The diagram makes the trade-offs visible. Source: Energy Digitalisation Taskforce report (2022), Ofgem Data Best Practice Guidance.

Tension 1: Open data vs security risk

Ofgem's Data Best Practice Guidance presumes data should be open by default. SCADA telemetry from substations, however, is a national security concern. The 2015 Ukrainian power grid cyber attack showed what happens when operational data reaches the wrong hands. The Data Triage Playbook tries to square this circle, but the line between "open for innovation" and "restricted for security" remains contested.

Tension 2: Centralisation vs fragmentation

Nordic countries use a single data hub. Norway's Elhub handles all meter data in one hop. GB uses five separate platforms (DCC, Elexon DIP, ElectraLink DTS, RECCo, NESO). The Data Sharing Infrastructure (DSI) aims to connect them, but governance is unresolved. A single hub is simpler, but creates a single point of failure and raises governance questions about who controls it.

Tension 3: Consumer consent vs system need

Ofgem argues half-hourly data is needed for settlement (no individual consent required, it is a legal obligation under the BSC). The ICO argues it is personal data requiring explicit consent. As of early 2026, this debate remains unresolved. The Consumer Consent Service (CCS), being built by RECCo, will eventually formalise the rules.

Tension 4: Innovation speed vs regulatory pace

AI and digital twins can transform grid planning today. RIIO price controls operate on 5-year cycles, and code modification takes 12 to 18 months. The system data infrastructure risks being permanently one regulatory cycle behind the technology curve. RIIO-3 (starting April 2026) includes a substantial digitalisation baseline, but no DSI licence condition.

Tension 5: National standards vs local variation

CIM provides an international data model (IEC 61970). Each of the 14 DNOs implements it differently, with varying maturity levels. The LTDSprogramme is closing the gap. Stage 1.3 completed November 2025, Stage 2 targets May 2026, Stage 3 targets November 2026. Full interoperabilityremains years away.

Common misconception

Energy data is just smart meter readings and monthly bills.

The GB energy system produces 87 distinct data types across 13 categories. Smart meter readings are one type within Category A. The full scope includes SCADA telemetry, gas chromatograph measurements, network topology data, wholesale market clearing prices, and regulatory compliance filings. Ofgem broadened the official definition in October 2024 to capture this full breadth.

Check your understanding

Which tension best describes the disagreement between Ofgem and the ICO about smart meter data?

Having mapped the tensions that make energy data difficult, it helps to know how this course structures the journey through them.

1.4 How to use this course

This course has 15 modules across three stages:

  1. Foundations (Modules 1 to 5): what energy data is, who produces it, how the physical network generates it, the complete 87-type taxonomy, and smart meters.
  2. Applied (Modules 6 to 10): the data lifecycle from meter to market, the regulatory hierarchy, data governance, privacy rights, and settlement mechanics.
  3. Practice and Strategy (Modules 11 to 15): international comparison, transformation programmes, digitalisation governance, CIM interoperability, and strategic planning.

Each module starts with a learning contract (the three outcomes you will achieve), includes inline knowledge checks, and ends with key takeaways. Each stage has a practice assessment you can use before attempting the timed stage test.

Key takeaways

  • Energy system data is any data produced by, for, or about the energy system. Ofgem broadened the definition on 8 October 2024 to cover 87 data types across 13 categories.
  • GB generates tens of billions of energy data points every day: 1.92 billion smart meter readings, about 69 million SCADA points per hour per large DNO, and continuous gas chromatograph measurements.
  • Five unresolved tensions define the landscape: open vs secure, centralised vs federated, consent vs system need, innovation vs price control, national standard vs local variation.
  • No tension has a clean answer. Every decision involves trading one legitimate goal against another.

Standards and sources cited in this module

  1. Ofgem, Decision on Data Best Practice Guidance

    8 October 2024

    Provides the official broadened definition of energy system data and the foundational rules referenced throughout this module.

  2. Energy Digitalisation Taskforce, Delivering a Digitalised Energy System

    Chapter 3: The role of data in the energy transition

    Sets out the case for treating energy data as a strategic national asset. The five tensions explored in this module derive from its analysis of competing stakeholder priorities.

  3. DESNZ, Smart Meter Statistics in Great Britain

    Quarterly publication, latest release Q4 2025

    Authoritative source for the 40 million smart meter installation figure and the 1.92 billion reads per day calculation.

  4. Distribution Connection and Use of System Agreement (DCUSA)

    Schedule 17 (operational data), licence condition SpC 9.5

    Defines DNO obligations for collecting, managing and sharing operational telemetry under Ofgem's Data Best Practice.