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Reference library

Energymanagementglossary.

Plain-English definitions of the terms and acronyms used across UK energy management, Net Zero, funded delivery and SECR/ESOS compliance.

SECRStreamlined Energy and Carbon Reporting
UK regulation requiring large companies to disclose energy use and carbon emissions in their Directors' Report.
ESOSEnergy Savings Opportunity Scheme
Mandatory UK energy assessment scheme requiring qualifying organisations to audit their energy use every four years.
EaaSEnergy as a Service
A subscription-based delivery model in which the provider owns and operates energy assets, and the customer pays for the outcome.
PPAPower Purchase Agreement
A long-term contract to buy electricity from a specific generation asset at a fixed price.
PUEPower Usage Effectiveness
A data-centre efficiency metric — total facility power divided by IT equipment power. Lower is better.
BMSBuilding Management System
The controls platform that orchestrates HVAC, lighting and other building services.
BESSBattery Energy Storage System
On-site batteries used for peak-shaving, self-consumption and grid services.
HH dataHalf-Hourly data
Electricity meter readings taken every 30 minutes — the base data layer for any credible energy model.
kWp
Kilowatt-peak — the maximum output rating of a solar PV system under standard test conditions.
LCOELevelised Cost of Energy
The average per-kWh cost of energy over the full lifetime of an asset.
REGORenewable Energy Guarantee of Origin
UK certificate proving one MWh of electricity was generated from renewables.
EPCEnergy Performance Certificate
The A–G energy rating shown on commercial and domestic buildings when let or sold.
MEESMinimum Energy Efficiency Standards
UK regulation setting minimum EPC ratings for let commercial and domestic property.
Scope 1
Direct greenhouse-gas emissions from sources owned or controlled by an organisation.
Scope 2
Indirect emissions from the generation of purchased electricity, steam, heat or cooling.
Scope 3
All other indirect emissions in the value chain, including purchased goods, use of sold products and business travel.
CDP
Non-profit disclosure system that many corporates use to report environmental data to investors and buyers.
SBTiScience Based Targets initiative
Framework for setting corporate emissions targets consistent with keeping warming below 1.5°C.
TCFDTask Force on Climate-related Financial Disclosures
Framework for disclosing climate risk in mainstream financial filings.
IPMVPInternational Performance Measurement and Verification Protocol
The standard M&V methodology used to demonstrate energy savings under performance contracts.
ISO 50001
International standard for energy management systems.
DUoSDistribution Use of System
The charges paid to distribution network operators for using the local electricity network.
TNUoSTransmission Network Use of System
Charges for using the national transmission network, historically driven by demand during Triad periods.
Triad
The three highest half-hour demand periods on the GB transmission network — historically used to set TNUoS demand charges.
G99
The UK grid connection standard for generators over 16A per phase.
PDCPublic Dividend Capital
Long-term public sector capital funding provided to NHS bodies.
M&VMeasurement and Verification
The methodology for quantifying and reporting energy savings from an efficiency project.
HHDHalf-Hourly Data supplier
An electricity supplier providing settlement data at 30-minute resolution.
Net Zero
A state in which residual greenhouse-gas emissions from an organisation are balanced by an equivalent amount of removals.
Digital twin
A calibrated software model of a physical asset used to predict behaviour and evaluate interventions.
IBSGInsurance-Backed Savings Guarantee
An insurance wrapper covering a shortfall between measured and guaranteed energy savings.