Utilities Glossary and industry jargon definitions

The utilities industry is awash with jargon and apparently meaningless abbreviations. We aim to explain what some of them mean. Please use either the search box (above and right) or the A to Z matrix to the left.



The 21st Century Network (21CN) programme is the network transformation project of the UK telecommunications company ...


3G is third-generation technology in the context of mobile phone standards. The services associated with 3G include w...



The Association of Cost Management Consultants. The professional body that regulates the conduct of members who provi...

Annual Quantity

The Annual Quantity (more commonly referred to as the AQ or Annual Offtake) is the amount of gas that National Grid (...


The agreed level of electricity supply capacity provided by the networks and the energy suppliers to meet the consume...


Balancing and Settlement Code (BSC)

The Code governing the operation of the balancing mechanism and the imbalance settlement process and the relationship...

Balancing mechanism

System used by electricity generators and suppliers to balance their supply and demand positions. Operated by Nationa...


The load continuously supplied by generators into the electricity networks over a period of tirne that demand does no...


BlackBerry Enterprise Server. The middleware software package that is part of the BlackBerry wireless platform from R...

BES Express

Blackberry Enterprise Server Express is a "cut-down" version of BES, with only 35 configurable security rules (the on...


The BlackBerry is a wireless handheld device introduced in 1999 which supports push e-mail, mobile telephone, text me...

BlackBerry Prosumer

A mobile email solution for smaller organisations who cannot justify the relatively high price of BlackBerry Enterpri...


Bluetooth is an industrial specification for wireless personal area networks (PANs). Bluetooth provides a way to conn...


Climate Change Levy

Tax intraduced in April 2001 to incentivise energy efficiency and help meet the UK's environmental commitments made a...

Connection agreement

Contract between electricity consumer and distribution network operator establishing the terms on which the customer'...


Carrier Pre-Select is a term relating to the telecommunications industry. It is the process where by a telephone subs...


The area of land within a boundary surrounding a property when not crossed by public highways, rail lines etc. Gas me...


Daily metered

A gas supply point whose consumption is measured each day by means of a data logger.

Daily metered customer

An interruptible gas supply point or a gas supply point with an annual consumption greater than 58,600,000kWh which i...

Data aggregator

The organisation appointed to aggregate electricity meter reading data received from data collectors to forward to su...

Data collector

The organisation responsible for collecting, processing and validating the meter reading data which is then passed on...

Data Logger

A data logger is a device which directly connects to either a gas, electricity or water meter to constantly record us...


Display Energy Certificates - From 01 October 2008 all large public sector buildings in the UK will have to display a...


DECT or Digital Enhanced Cordless Telecommunications is an ETSI standard for digital portable phones, commonly used f...

Demand level

The consumption of electricity in half-hourly intervals actually used on a national basis.

Demand side management

Refers to measures that can be taken on the customer's side of the meter to change the arnount or timing of consumption.

Distribution losses

Charges relating to electrical losses that occur as electricity is transmitted through the lines of the DNO (see below).

Distribution use of system

Charge levied by the DNO for the transmission of electricity through its local network.


Manages the installation and upkeep of their cabling and the dlstibution of electricity from the point where it leave...



Extra High Voltage.


The balancing and settlement code company that procures and provides services to administer and implement the balanci...

Emission allowance

Typically, emissions reduction schemes set a cap for total emissions for each participant over a period and allocate ...

Emissions cap

The limit on emissions applicable to a participant over a period of time used to allocate emissions allowances.

Emissions credit

Countries and companies can earn tradable emissions credits by undertaking projects that reduce emlssions over and ab...

Emissions trading

Countries and companies can trade emissions allowances and emissions credits. Emissions trading is one of the Kyoto m...

Emissions trading scheme

Scheme for trading emissions allowances and emissions credits.

Entry capacity

The quantity of gas that a shipper is entitled to put into the system at a particular input point on a day.


The Directive on the energy performance of buildings (EPBD) is the Directive 2002/91/EC (EPBD, 2003) of the European ...


The European Telecommunications Standards Institute (ETSI) is an independent, non-profit, standardization organizatio...

Exit capacity

The quantity of gas that a shipper is entitled to withdraw from the national transmission system in order to meet the...

Exit zone

A geographical gas distribution area wholly contained within a local distribution zone which groups supply points tog...


Firm gas

A guaranteed supply of natural gas that will not be subject to interruption.

Fossil fuel

Coal, natural gas and fuels derived from crude oil.


Factors other than psychological or technical that influence the price development on the physical or futures market,...


Gas Producer

A Company that explores for gas, drills the wells and extracts the gas from the seabed.

Gas year

The period commencing 06:00hrs 01 October through to 06:00hrs 01 October the following year.


Producer of electricity

Gershon Review

The Gershon review was a review of efficiency in the UK public sector conducted in 2004-5 by Sir Peter Gershon. Gordo...


General Packet Radio Service is still the most widely used mobile data service in use, but is rapidly being overtaken...

Grid supply point

Point between transmission and distribution systems where responsibility for electricity supply transfers from Nation...


The Global System for Mobile communications (GSM: originally from Groupe Spécial Mobile) is currently still the most ...


Gigawatt = 1,000 MW


Half Hourly electricity supply

A half-hourly electricity supply is usually greater than 70kVA in size, and the meter is able to record usage data ev...

HH data

Half-Hourly data. Electricity consumption data recorded every half hour and collected by the metering system.


HM Revenues and Customs

Host REC

A historic term used to describe the Regional Electricity Companies in the Electricity Act 1989.


High Speed Downlink Packet Access is currently the fastest mobile internet service readily available in the UK. It pr...


High Voltage. Supply voltage over 1,000 volts (1kV).



Industrial and Commercial (non-domestic sector).


Situation where there is a difference between the amount of power produced (supply) and the amount of power contracte...

Imbalance cost

The cost to the energy supplier of being in an imbalance situation.


The International Mobile Equipment Identity number, or IMEI number, is unique to every GSM and UMTS mobile phone. It ...


A gas pipeline linking the UK and the Continent e.g. from Bacton to Zeebrugge.

Interruptible gas

Gas supply that may be interrupted by Transco or the supplier to maintain the transmission/distribution system to all...



Kilovoltampere. Unit of measurement for electricity available capacity and in some cases maximum demand. Referred to ...


A unit of power equal to 1,000 Watts. A watt is the standard power unit and a measurement of demand, including maximu...


Kilowatt Hour. A measurement of energy consumed. The amount of energy used in an hour. Energy (kWh) = Power (kW) x Ti...


Least Cost Routing

In international voice telecommunications, least cost routing (LCR) is one of the processes that can provide organisa...


Levy Exemption Certificates provide exemption from the Climate Change Levy for electricity supplies from renewable an...

Levy exemption certificate

Exemption from the Climate Change Levy on the electricity to which the LEC relates. LECs are issued for electricity g...

Line loss factor

Indicator within the electricity supply number of distribution line loss for a meter point.

Line pack

Method used for providing short-term gas storage in which natural gas is compressed in transmission pipelines, provid...

Liquified Natural Gas

Oilfield or naturally occurring gas, chiefly methane, liquefied for transport or storage.

Load Factor

Ratio between average electricity usage and maximum demand. Calculated by the formula:Load Factor = (Total Units / No...

Local distribution zone

A geographic area for which the total input and output demand for gas can be measured each day. LDZs are supplied by ...


Low Voltage. Electricty supply voltage below 1,000 volts.


Maximum annual quantity

Annual quantity of gas multiplied by the MAQ percentage.

Maximum daily quantity

Maximum aggregated daily quantity of gas to be delivered to a supply point.

Maximum Demand

The highest average electricity demand occurring in a half hour period. Maximum demand tariffs comprise of a) fixed m...

Meter operator

The organisation appointed to install and maintain metering equipment.

Meter Operator Agreement

Agreement between the customer and the nominated meter operator.


Multimedia Messaging Service (MMS) is a standard for telephony messaging systems that allows sending messages that in...


A Meter Point Administration Number also known as MPAN, Supply Number or S-Number is a 21 digit reference, used in Gr...


Meter Point Administration Service. Provides information regarding electricity supply to properties in their distribu...


The Meter Point Reference Number is the equivalent for gas supply to the MPAN used for electricity supply.


Megawatt = 1,000 kW


Megawatthour = 1,000kWh


National Grid Transco

Operates the high voltaae national electricity transmission network and the gas transportation networks in England an...

National offtake

A gas metering point defining the boundary between the national transmission system and theLocal Distribution Zone.

National transmission system

The high-pressure network of pipes that transports gas between terminals, storage facilities and Local Distribution Z...

Network code

Legal and operational framework that defines the right and obligations of National Grid Transco and gas shippers/supp...


Non- Geographic Number e.g. a number prefixed 0800, 0845, 0870, 0871 etc. which is not geographically tied to a parti...

NHH supply

A Non-Half Hourly electricity supply is one where the meter is incapable of passing usage information by remote commu...

Nominated consumption

Annual quantity of gas nominated by the customer as their annual estlmated consumption requirement.

Nominated interruption

The designation by National Grid Transco of a gas supply point as being interruptible, allowing Transco the right to ...

Non-daily metered

Gas supply point whose meter is not fitted with a data logger and is read monthly, six monthly or at longer intervals.


Offtake point

Outlet of any control valve at any gas supply meter point.



A Private Branch eXchange (PBX) is a telephone exchange that serves a particular business or office, as opposed to on...


Public Electricity Supply company.


A personal information manager (PIM) is a type of application software that functions as a personal organizer. As an ...

Power factor

The proportion of total electricity supplied to a site that is converted into useful energy output, as opposed to the...

Public Gas Transporters

Licensed gas pipeline operators.

PUK Code

A Personal Unlocking Key code is used in GSM mobile phones, and some smartcards. Most mobile telephones offer the fea...


Reactive power charge

Charge for reactive energy if the average power factor falls below a preset level, normally 0.9

Regional electricity company

Local electricity distribution monopoly.

Renewable energy

Generation of electricity from infinite resources. e.g. wind power or hydro-electricity.

Renewables obligation

An obligation on electricity suppliers to ensure that a specified percentage of the total electricity supplied to the...


The Renewables Obligation (RO) is designed to incentivise the generation of electricity from eligible renewable sourc...



See Supply Number or MPAN

Settlement charge

A flat fee to cover the collection of electricity data by the data collector.

Settlement period

A half-hour period ending on the hour or half-hour.


An organisation that contracts with National Grid Transco for the use of network code transportation and storage serv...

Shipper nominated interruptible

A gas supply that can be interrupted by the shipper to enable it to balance its supply and demand.


A Subscriber Identity Module (SIM) is a removable smart card for mobile phones. SIM cards securely store the service-...

Site nomination

Process by which a shipper informs National Grid Transco it wishes to supply gas to a new customer supply point.

Smart Meter

A Smart meter generally refers to a type of advanced meter (usually an electrical meter) that identifies consumption ...


A smartphone is a full-featured mobile phone with personal computer like functionality. Most smartphones are camera p...


The Short Message Service (SMS) is a means of sending short messages (of up to 160 characters) to and from mobile pho...

Standing charge

A charge designed to average over and recover from all customers on each tariff the elements of cost which are indepe...

Supplementary number

Top line of the MPAN or Supply Number. Indicates the profile class and meter and time switch details.

Supply Number

The Supply Number, or S-Number or MPAN, is the unique reference number of each electricity supply point. The Supply N...


Take or pay

A contract whereby a customer must pay for a specific minimum quantity of gas irrespective of usage.


Published standard charges applied to gas and electricity supplies that are not on a bespoke negotiated contract.


Factors other than fundamental or psychological ones that influence future price developments e.g. trend indicators, ...

Third party access

Right of any gas or electricity supplier to have access to the national transmission system of that energy even thoug...


National network for movement of power between power station and local distribution networks.

Transmission losses

Charges relating to electrical losses that occur as power is transmitted via the National Grid.

Transmission Use of Systems

Charges levied by National Grid Transco for the transmission of electricity through the National Grid.


Movement of gas from the beachhead terminal to Local Distribution Zones.

Transportation charge

The charges associated with transporting gas from the beach to Local Distribution Zones. Prices are based on a distan...

Transporter - gas

National Grid Transco or any other holder of a public gas transporters licence (including the new distribution networ...


The three halt-hourly periods in the year with peak electricity consumption, with each period at least 10 days apart,...


Terrawatt = 1,000GW


Terrawatthour = 1,000GWh



The equivalent of a SIM in UMTS (3G) mobile phones is called the Universal Integrated Circuit Card (UICC).


UK Data Collection Service. Former name of IM-Serv


Universal Mobile Telecommunications System (UMTS) is one of the third-generation (3G) mobile phone technologies in us...


An uninterruptible power supply (UPS), uninterruptible power source or sometimes called a battery backup is a device ...



Voice over Internet Protocol, also called VoIP, IP Telephony, Internet telephony, Broadband telephony, Broadband Phon...


A virtual private network (VPN) is a private communications network often used by companies or organizations, to comm...



WAP (Wireless Application Protocol) or Wait And Pay as it is sometimes caustically referred to, is an open internatio...


Price paid on the open markets for energy only i.e. excluding transportation and distributioncharges, supplier margin...


Wi-Fi was originally a brand licensed by the Wi-Fi Alliance to describe the embedded technology of wireless local are...


A wireless LAN or WLAN is a wireless local area network, which is the linking of two or more computers without using ...



The company that maintains the gas sites and meters database and holds the key supply point data used throughout gas ...

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