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Glossary of Terms

Energy jargon explained in less than 20 words

All you need to know in the time you can spare.
  • Advanced Meter - Meters that automatically pass accurate meter readings to energy suppliers
  • Amp - An amp is electrical current
  • Annualised Advance - The actual rate of consumption over a period between two actual meter readings 
  • AQ (Annual Quantity) - The term used to describe the annual consumption of a gas customer’s meter
  • Apparent Power - Apparent power is equal to the product of volts and amps
  • Applying supplier - The future supplier of a meter, also known as the incoming supplier or new supplier when subject to a transfer
  • Available Supply Capacity (ASC) - The maximum amount of electricity that can be drawn via the meter at any point. Measured in KVA
  • Balancing and Settlement Code (BSC) - The rules that govern the settlement and metering systems in the electricity market. Managed by ELEXON
  • Big 6 - The major energy suppliers in the UK: BGB, SSE, nPower, E.ON, Scottish Power and EDF
  • Buy-Out Fund - Where a supplier is unable to meet the RO they must make payments into a fund for renewable investment
  • Calorific Value (CV) - The quality of gas measured by the release of energy when gas is completely combusted under specified conditions
  • Capacity - As ASC, the maximum amount of electricity that can be drawn via the meter at any point. Measured in KVA
  • Change of tenancy - The situation where a business energy customer moves in to a premise without a contract being in place
  • Climate Change Levy (CCL) - Introduced in 2001 and levied on businesses to incentivize the use of renewable to increase efficiency and reduce carbon emissions
  • Communications Service Providers (CSP) - The telecommunications businesses, Arqiva  & Telefónica who will facilitate the full functionality of smart metering
  • Consumption - The absolute usage of a meter, derived from the meter advance and applicable to any time period, most often annual 
  • Contract End Date - The end of a fixed price period, the supplier will supply past this date until the supply end date
  • Contracts for Differences (CfDs) - Replacement for RO, mechanism for top-up payments to renewable plants when electricity price is below a set level
  • Correction Factor - The measure used to convert cubic meter gas units into kWh, the standard correction factor is 1.02264
  • Credit Score - A snap shot indicator of a business’ credit worthiness used to determine the products, rates and terms suppliers will offer 
  • D0010 – Meter Readings - The flow that communicates Meter Readings taken from a customer meter to the industry
  • D0019 - Metering System EAC/AA Data - Derived from the D0010, the flow communicates the estimated annual consumption of a meter
  • D0036 - Validated Half Hourly Advances for Inclusion in Aggregated Supplier Matrix - The flow that contains the meter readings, demand and advances of a Half Hourly Meter
  • D0055 - Registration of Supplier to Specified Metering Point - Registers the supplier’s intent to register a meter to their portfolio
  • D0057 - Rejection of Registration - Reports a rejection of the D0055 because certain critical industry data does match that held by MPAS
  • D0058 - Notification of Termination of Supply Registration - Informs the incumbent supplier that the new supplier is intending to take ownership of the meter on the date stated
  • D0064 - Notification of an Objection to Change of Supplier Made By the Old Supplier - Notification that the incumbent supplier is ‘objecting’ to the transfer of the meter point to the new supplier
  • D0067 - Notification of an Objection to Change of Supplier Sent to the New Supplier - Sent to the new supplier to inform them that the incumbent supplier has objected to the transfer of the meter
  • Data Aggregator (DA) - The entity that sums the meter readings gathered in order to identify the demand levels in any combination of meters
  • Data Collector (DC) - The entity that collates the meter readings and attributes them to metering systems, customers and suppliers
  • Data and Communications Company (DCC) - The entity responsible for linking the 53 million smart meters with the systems of the energy suppliers and network operators
  • Data Flow - Flows transmitted between the MOP, DC, DA, MPAS, Supplier and Distributor via the DTN facilitating actions in the competitive market
  • Data Retriever (DR) - The ‘man in the van’ who reads meters; in a Smart Meter this can simply be a SIM card
  • Data Service Provider (DSP) - The entity that operates the system controlling the movement of smart meter messages, a smart meter era DR and DC
  • Data Transfer Catalogue (DTC) - The dictionary of the various flows, activities and participants within the DTN
  • Data Transfer Network (DTN) - The data network that enables automated communications between the relevant market participants facilitating change of supplier activity
  • DECC (Department of Energy & Climate Change) - The government department led by Ed Davey responsible for the energy industry & which controls Ofgem
  • Deemed rates - Standard charges applied to Change of Tenancy customers before they agree or refuse a contract with the incumbent supplier
  • Delphi - The numeric score provided by Experian to represent a business’ credit worthiness
  • Distribution Network (Distributor) - The 14 ‘regional’ networks that connect to the transmission system and manage electricity distribution to homes and businesses
  • DUoS (Distribution Use of System) - The charges related to a meter’s usage of the distribution network representing around 18% of the average business energy bill
  • Economy 7 Meter - A two-rate meter to provide cheaper energy off-peak between 1am and 8am and commonplace in bakeries and take-aways
  • ELEXON - The party that manages the BSC focusing on settlement processes, metering systems & managing supplier adherence to industry rules
  • Embedded generation - Small scale generation, often renewable, that is in place at a site of an energy consumer and not a generator
  • Energy Ombudsman - Part of the Ombudsman Service covering  the communications, energy, property and copyright licensing industries to whom escalated complaints are made
  • Energy Supplier - The entity that is the retail business who bills and services end user customers e.g. BGB, nPower, E.ON
  • EAC (Estimated Annual Consumption) - The term used to describe the forecast annual consumption of a electricity customer’s meter in lieu of an Annualised Advance
  • Evening Weekend Meter - A two-rate meter measuring day & evening / weekend usage. Commonplace in bakeries and take-aways
  • Evening Weekend & Night Meter - A three-rate meter measuring day evening / weekend & night usage. Commonplace in pubs, nightclubs and restaurants
  • Feed in Tariff (FIT) - A scheme to incentivise renewable energy generation. Levied on all consumers to reward those businesses with eligible generation
  • Fossil Fuel Levy (FFL) - A forerunner of Climate Change Levy, introduced in 1989 and which has been rated at 0 since 2002
  • GEMSERV - The private business contracted to operate the MRA as MRASCO and the SEC
  • Generators - The producer of electricity using coal, gas, hydro, oil, wind or waves but whose fundamental principle remains the same
  • GWH (Giga Watt Hour) - 1,000,000 kWh, 1,000 MWH
  • Global Complex - The connected nature of the globalised energy market whereby e.g. demand in Japan can affect supply and price in the UK
  • Grid - The network that transports energy from source to destination. Also describes the payment market between suppliers & generators
  • GSP (Grid Supply Point) - The point in each regional distribution network where the transmission network connects to it
  • Half Hourly Data (HHD) - Data sourced from a half hourly meter delivering 17,520 recordings of demand from each meter
  • Half Hourly Meter (HH Meter) - A high demand meter (>100kW) that records and transmits usage every half hour
  • Higher Distribution Cost Levy (Assistance for Areas with High Electricity Distribution Costs) - A charge to reduce the cost of the distribution of electricity in certain areas such as the North of Scotland.
  • Incumbent supplier - The current supplier of a meter, also known as the outgoing or old supplier when subject to a transfer
  • Industrial & Commercial - Those customers that consume more than 300,000kWh of gas or electricity per annum and often those electricity customers fitted with a half hourly meter.
  • Interruptible Supply - Specialised contracts for intensive gas users to cut demand in peak periods to balance the network 
  • kVA (Kilo volt amperes) - A measure of the difference between real and apparent power arising because of inefficiencies in electrical transmission
  • kW (Kilowatt) - A measure of power output or demand of a particular item, it is equal to one thousand watts
  • kWh (Kilowatt hour) - A measure of power taken over time; 1,000 watt-hours or 3.5 mega joules
  • Levy Exempt Power - Electricity from a non-fossil fuel source of generation e.g. renewable energy and therefore not liable for CCL
  • Line Loss Factor (LLF) - A multiplier applied to a meter & used to estimate the losses in transporting energy along the distribution network
  • Liquidity - Availability of commodity in a traded market, the higher, the stronger liquidity and lower the influence of a single transaction
  • LNG (Liquid Natural Gas) - Gas converted & compacted to less than 1/600th of its gaseous state to facilitate ease of transportation over long distances
  • Load Factor - The absolute consumption divided by the maximum energy ‘demanded’ at a specific point as measured by a Maximum demand meter 
  • Load Profile - The pattern of a meter’s electricity usage by period to a half hour granularity. Eight profile classes represent standard profiles 
  • Losses - Energy is lost during transportation, metered demand is therefore subject to a loss factor to gross up demand to include losses 
  • Maximum Demand (MD) - The maximum energy ‘demanded’ by a metering system at a specific point
  • Maximum Demand Meter (MD Meter) - A meter that measures the maximum energy ‘demanded’ at specific points & the absolute consumption to provide the load factor
  • Measurement Class - The aggregation & settlement classification for a meter i.e. Non Half Hourly or Half Hourly
  • MWH (Mega Watt Hour) - 1,000 kWh 
  • Meter advance - The gap between two meter readings derived by subtracting the earlier read from the later 
  • Meter Asset Manager (MAM) - The entity who maintain the meter installed in a premise 
  • Meter Asset Provider (MAP) - The entity who owns the meter installed in a premise 
  • Meter Operator (MOP) - The collective name for the MAM and MAP, the owner and maintainer of a the meter installed in a premise 
  • Meter Serial Number - The non-unique serial number of a gas or electricity meter, used to identify the meter and not the supply point 
  • Meter Timeswitch Code (MTC) - Identifies the rate/time periods that a meter will support to measure meter consumption across differing periods
  • Micro Business - A business using under 100,000kWh of electricity, 293,000kWh of gas, with fewer than 10 staff and turnover less than €2m
  • Micro Watt Hour - 1,000,000th of a kWh 
  • Milli Watt Hour - 1,000th of a kWh
  • M Number (MPRN, Meter Point Reference Number) - The unique reference applied to the gas supply point in a premise, the gas industry version of the S Number 
  • MPAN Core - The unique reference for a metering system at a supply point. The ‘bottom line’ of the S Number 
  • MPAS - The 14 regional areas that hold centralised data about each customer meter and supply point 
  • MRA (Meter Registration Agreement) - The rules that govern the DTN and underpin the registration processes of the electricity market. Managed by MRASCO.
  • MRASCO - The organisation that is contracted to develop and manage the MRA. Operated by GEMSERV. 
  • National Grid - The Company that owns the electricity transmission network and the gas pipeline network 
  • Network Code (The Uniform Network Code) - The legal framework of the gas industry designed to facilitate competition. 
  • Objection - The process within the registration window where the supplier blocks the transfer due to debt or contracts being in place 
  • Ofgem - The non-customer facing industry regulator responsible for the competitive energy market, a non-ministerial government department reporting to DECC 
  • Out of Contract rates - Punitive rates charged to customers who have refused contract terms yet remain on supply with the supplier. 
  • Pass Through Charges - Elements of the energy price that can be changed and passed through under the contract terms e.g. levies, transportation & metering costs. 
  • PWH (Peta Watt Hour) - 1,000,000,000,000 kWh, 1,000,000,000 MWH, 1,000,000 GWH, 1,000 TWH. 
  • PP10 - HMRC’s Climate Change Levy Relief Supporting Analysis document intended to prove, via supporting analysis, a business’ claim for relief. 
  • PP11 - HMRC’s document to inform an energy supplier of the level of relief to be applied against a business’ CCL liability.
  • Producer - The entity who extracts gas through on and offshore wells and deliver it to the market. 
  • Profile Class - A classification representing one of 8 generic demand shapes approximating when a typical customer uses their energy.
  • Profile Class 1 - A standardised load profile for domestic unrestricted customers using a single rate meter
  • Profile Class 2 - A standardised load profile for domestic unrestricted customers using an economy 7 two-rate meter
  • Profile Class 3 - A standardised load profile for non-domestic unrestricted customers using a single rate meter
  • Profile Class 4 - A standardised load profile for non-domestic unrestricted customers using an economy 7 two-rate meter
  • Profile Class 5 - A standardised load profile for non-domestic Maximum Demand (MD) with a Peak Load Factor (LF) of less than 20%
  • Profile Class 6 - A standardised load profile for non-domestic Maximum Demand (MD) with a Peak Load Factor (LF) of between 20% and 30%
  • Profile Class 7 - A standardised load profile for non-domestic Maximum Demand (MD) with a Peak Load Factor (LF) of between 30% and 40%
  • Profile Class 8 - A standardised load profile for non-domestic Maximum Demand (MD) with a Peak Load Factor (LF) of over 40%
  • Reactive Power - Created when current and voltage are not in phase, measured in var and also known as apparent power 
  • Real Power -  Real power is the amount of actual power that can be drawn from a circuit. 
  • RECs (Regional Electricity Companies) - The pre-privatisation era description of monopoly regional energy businesses e.g. MEB, now nPower or EMEB, now E.ON
  • Registration - The process by which a customer is transferred from their existing supplier to their chosen new supplier 
  • Registration Window - The 28-day period prior to the intended transfer date within which the new supplier applies for registration of the meter. 
  • Regulator - Ofgem, the non-customer facing industry regulator responsible for the competitive energy market, a non-ministerial government department reporting to DECC 
  • Rejection - The process within the registration window where MPAS rejects the application due to mis-matching industry data 
  • Renewables Obligation (RO) - An obligation placed on UK electricity suppliers to source a set % of their energy from renewable sources. 
  • Renewable Obligation Certificates (ROCs) - Certificates of provenance, under the RO presented to Ofgem to prove the source and status of the energy.
  • Retail Price - The final price for energy that the customer pays. Consisting of wholesale energy, transportation, metering, losses, levies, & supplier margin.
  • Seasonal Time of Day Meter (STOD) - A complex meter with up to 56 rates across night, day, peak & other periods measured separately by season. 
  • Settlement - The process, in the electricity market, total and individual demand is apportioned to each supplier, customer & GSP group 
  • Settlement Period - Each half hour in the electricity market is a settlement period within which total and individual demand is apportioned 
  • Settlement Register - A register on a meter related to a time period & used in the industry settlement process to determine usage
  • Shipper - The entity that arranges for the gas transporter to move the gas from the producer to the customer.
  • Smart Energy Code (SEC) - The multiparty agreement that sets out the contractual relationship between the DCC and the DCC Service Users. Operated by GEMSERV.
  • Smart Meter - Meters that automatically pass accurate meter readings to energy suppliers and which support other functions including enabling smart appliance operation.
  • Smart Meter Roll-Out - The government project to install 53 million Smart & Advanced Meters between 2015 and 2020
  • SME (Small & Medium Enterprise) - Independently owned businesses Small: below £2.8m turnover & 50 employees Medium: below £11.2 million turnover & 250 employees
  • S Number - A unique identifier used in the electricity market to define the supply point for a meter and its generic characteristics.
  • Soft Credit Check - A credit check that leaves no footprint on financial records yet determines the products, rates and terms suppliers will offer
  • Spill - Embedded generators releasing surplus energy to the ‘grid’ to take advantage of price opportunities as a traditional generator would
  • Standard Meter - A single rate meter, providing a single tariff for all units used. Ideal for offices, shops & cafes.
  • Storage - Primarily gas however small amounts of electricity can be stored, with new technologies exploring long-term mass electricity storage. 
  • Supply End Date The final date a supplier supplies a meter, after which they no longer hold responsibility for the energy delivered. 
  • TWH (Tera Watt Hour) - 1,000,000,000 kWh, 1,000,000 MWH, 1,000 GWH 
  • Therm - The historic measure of gas consumption, equal to 100,000 BTU (British Thermal Units) and 29.3 kWh 
  • TPI (Third Party Intermediary) - A broker, consultant, agent or price comparison website, i.e. any non-supplier party involved in the business energy sales process. 
  • TNUoS (Transmission Use of System) - Charges for a meter’s usage of the transmission network, varying by length & location representing 7% of the energy bill 
  • Top Line - The first 8 digits of the S Number displaying Profile Class, Meter Timeswitch Code and Line Loss Factor. 
  • Transco - Part of National Grid, the company that owns the gas pipeline network of the UK 
  • Transmission Network - The wires and pylons that carry electricity from generators to the distribution networks. Owned and managed by National Grid 
  • Transportation - The charges for and process by which gas and electricity is delivered from the generator to the meter point.
  • Transporter - The entity, primarily National Grid Transco, that transports gas from the producer to consumers. 
  • Triad - The three highest demand points between November and February, used to determine transmission charges applied to the largest businesses.
  • Vertical integration (VI) - The principle of a business owning more than one area of the energy chain: generation, transportation, metering and/or supply.
  • Volt - A volt is electrical pressure.
  • Watt - A watt is real power.
  • Wholesale Market - The energy market where suppliers, generators, traders and customers purchase electricity and gas via bilateral contracts or through energy exchanges.