Active Power

Also known as ‘Real Power’ or simply ‘Power’. Active power is the rate of producing, transfer or using electrical energy. Measured in watts and often-expressed in kW or MW.

Agreed Capacity

An agreed amount of electrical load for a property, as stated in the property’s Connection Agreement with the local Distribution Network Operator (DNO).

Annual Quantity (AQ)

It is the sum of the annual consumption of all meters on a site. This comes from National Grid, and is based on historical usage from previous years. Measured in kWh (electricity) or Therms (gas). Supply Point AQ is the total annual consumption of all meters on a site. Meter Point AQ is the AQ for a particular Meter Point.

Apparent Power

The product of the voltage (volts) and the current amps. Comprises both active and reactive power. Measured in kVa or MVa.

Automatic Meter Read (AMR)

AMR is the term given to a system that provides automatic meter readings remotely. It uses telephone technology and holds the ability to transfer data into a billing system.

Availability (KVA)

Availability (kVA) or Agreed Capacity refers to the limit of capacity for a site. E.g. if a site has an Availability of 150 kVA then maximum demand should not exceed that figure at any time. It is set and charged by the local Distribution Network Operator (DNO), according to the kVA of a premise. This fee covers investment and maintenance of the electricity network and can also be called the Capacity Charge. Customers pay a fee (per unit) according to the agreed capacity for that site. In theory, maximum demand should not exceed the agreed capacity at any time.

Available Supply Capacity (ASC)

Also known as the Agreed Capacity, this is an agreed amount of electrical load for a property, as stated in the property’s Connection Agreement with the local Distribution Network Operator (DNO).

Balancing Mechanism

The mechanism used by the National Grid Company to balance the supply and demand of electricity.

Base Load

Base load is the level below which electricity demand never drops, i.e. a site with a high maximum demand of 750 kVa whose demand never drops below 250 kVa would have a base load of 250 kVa.

Calorific Value (CV)

Amount of heat given by the specified quantity of gas. This is used to calculate the energy consumed based on the volume of gas used. It is measured in joules per kilogram.

Capacity Charge

A set charge by the local Distribution Network Operator (DNO) for investment and maintenance of the electricity network, based on the Agreed Capacity of a property. This can also be called the Availability Charge.

Climate Change

The variation in the Earth’s global climate over time. Man-made climate change is a variation directly attributable to human behaviour.

Climate Change Agreement

An agreement between the Government and a business user, whereby a reduced rate of Climate Change Levy is payable in return for a commitment by the user to achieve certain pre-determined targets for energy usage or carbon emissions.

Climate Change Levy (CCL)

CCL is a government-imposed tax to encourage reduction in gas emissions and greater efficiency of energy used for business or non domestic purposes.  CCL is chargeable only on units/kWh used and not on any other component of the bill, e.g. standing charge.  The rate of CCL is now index-linked and therefore likely to increase on 1 April each year.

Under current legislation:

  • where VAT is charged at the standard rate, CCL (plus VAT on CCL) will usually be added to the bill
  • where VAT is charged at the reduced rate, the supply is automatically excluded from CCL
  • green energy (i.e. from renewable sources) is automatically exempt from CCL.

Where VAT is charged at the standard rate but sites are entitled to full or partial relief from CCL, you will need to submit a PP11 Supplier Certificate for each site to advise us what percentage of relief is applicable.  PP11s are only available from HM Revenue & Customs (HMRC) and can be downloaded from their website  Please note that PP11 Supplier Certificates are not transferable between suppliers.

Climate Change Programme

Published in 2000, sets out the Government and Devolved Administration strategic approach to tackling Climate Change and meeting the UK’s Kyoto target of a 12.5% reduction in greenhouse gas emissions from 1990 levels by 2008-2012 and the domestic goal of reducing CO2 emissions by 20% by 2010.

Combined Half Hourly (HH) Data Charge

Costs associated with collecting and handling metering data from half hourly (HH) read meters.

Commodity Charge

A fee levied by National Grid on the quantity of gas transported through the system.

Confirmation Reference

A unique number assigned by National Grid to a customer.

Connection Agreement

A document which states the Agreed Capacity for a property with the local Distribution Network Operator (DNO).

Contract Price

Price of a unit of gas or electricity which the shipper charges the customer.

Contract Price Structure

This indicates a supply offer, which has all delivery charges (DUoS & TUoS) built into the unit rates for the supply of electricity.

Corrector Meter

For sites using large amounts of gas it is often deemed necessary to measure the temperature and pressure variations more accurately rather than just applying a fixed conversion factor. In these cases an additional “corrector” meter is attached to the meter.

Cost To Serve

These are the costs that are incurred as an energy supplier. These include the costs of maintaining IT systems, paying staff to manage customer accounts.

CT Metering

Metering that is 100 amp and above.

Daily Meter (DM)

A supply point whose annual quantity (consumption) is greater than 58,600,000kWh (2,000,000 therms per annum), will have a mandatory DM meter fitted.

Data Aggregator (DA)

The agent appointed to aggregate the meter reading data which is received from the Data Collectors (DC) and subsequently forwarded to the Supplier.

Data Collector (DC)

An organisation accredited by the Pool Accreditation Body to carry out Data Collection for Half Hourly (HH) Metering Systems. The DC is appointed by the Suppliers to retrieve and validate metering data and forward it, by Metering System, to the Data Aggregator. The DC may be appointed by the customer but must always be accredited and contracted to the customer’s Supplier.

Data Logger

A device used to record meter readings and automatically transmit them to the meter reading agency.

Deemed Contract

A contract which is deemed to apply when a customer begins a new supply at a property and has not signed a written contract for its supply. These contracts have a defaulted rate for supply until a customer requests a fixed price for a fixed period.

Department of Trade and Industry (DTI)

The Department of Trade and Industry, a UK government department which, among other responsibilities, has a leading role the UK Government oversight of energy policy (UK).

Direct Current (DC)

An electrical current which flows only in one direction in a circuit. Batteries and fuel cells produce direct current.

Distributed and Microgeneration

This is when electricity is generated for local distribution and is not connected directly to the National Grid. Microgeneration is typically used to describe smaller scale generating technology. Both of these types of generation have a role to play in Britain’s energy mix, although it is important to be realistic about the overall size of the contribution they may not be the best economic or most environmentally friendly solution in every case.

Distributed Generation

Electricity generation usually on a relatively small scale that is connected to the distribution networks rather than directly to the national transmission systems.

Distribution Losses (Dloss)

Charges for the loss of distributing power through the wires.

Distribution Network Operators (DNO)

Companies that are responsible for operating the networks that connect electricity consumers to the national transmission system and provide interconnection with embedded generation. There are 14 regional distributors who maintain the electrical network.

Distribution Use Of System Charges (DUOS)

These charges are published costs made by each Distribution Company for delivering electricity from the Grid Supply Point to the customer’s premises.

District Network Operator (DNO)

The DNO manages the installation and upkeep of the cabling, and the distribution of electricity to the grid supply point.

Domestic / Non Domestic Supply

A Supply Point with an AQ of 73,200kWH (2500 therms) or less, is deemed as a domestic site. (This does not mean the user is necessarily residential). A supply point with an AQ of over 73,00kWh is deemed as non-domestic.

Please see “Micro-business”.

Electric Current

The rate at which electricity flows through an electrical conductor, usually measured in amperes (amps).

Electricity Meter

A device that measures the amount of electricity used.

Electronic Data Interchange (EDI)

Allows the transfer of bill data through a secure channel so that customers can receive their bills in a specified format.

Energy Charter Treaty (ECT)

A multilateral treaty to promote trade, investment and transit of energy products between Contracting Parties and sets a standard for non-discriminatory access to energy supplies.

Energy Cost

This is the cost of the electricity purchased on the wholesale market at the Notional Balancing Point (NBP) to cover current and predicted future usage. It is the single biggest component of the unit price and typically accounts for between 60 and 80% of a business’s total bill. In the industry, this element is called Energy at NBP (Notional Balancing Point).

Energy Efficiency

Achieving desired levels of lighting, heating or cooling for minimum energy use. Cutting down on waste energy. A good example is an energy efficient light bulb which produces the same amount of light as a conventional bulb but uses up to 75% less energy to do so.

Energy Efficiency Commitment (EEC)

Formerly known as Energy Efficiency Standards of Performance (EESoP), is an obligation placed on all domestic energy suppliers to achieve a specified energy saving target through the installation of energy efficiency measures in homes across Great Britain.

Energy Only

An offer of electricity that has no delivery charges (DUoS & TUoS) added at the point of quotation.

Energy Performance Certificate (EPC)

EPC is intended to inform potential buyers or tenants about the energy performance of a building, so they can consider energy efficiency as part of their investment or business decision. The scale is from A-G, A being the most efficient.

Energy Saving Trust (EST)

The EST is an independent non-profit organisation, set up and largely funded by the Government to manage a number of programmes to improve energy efficiency, particularly in the domestic sector.

Energy Services Directive (ESD)

The Directive’s full name is the EC Directive on Energy End Use Efficiency anad Energy Services. It aims to promote energy efficiency in the UK by developing a market for energy services and delivering energy efficiency programmes and measures to energy end users.

Environment Agency

The leading public body for protecting and improving the environment in England and Wales.

European Emissions Trading Scheme

The EU emissions trading scheme, introduced in April 2005. See the section on ‘Carbon emissions trading scheme’, above.

Fixed Charge

A daily, monthly or quarterly charge levied by the supplier and is in addition to the standing charge.

Fixed Term Contracts

Supply contract for a fixed price, over a fixed period of time which gives customers a constant price. Fixed Charges include Standing Charges and Availability Charges.

Force Majeure

Unexpected and disruptive event beyond the control of buyer or seller that interferes with a party’s ability to perform under a contract. A force majeure event will typically relieve a party from a contractual obligation.

Fossil Fuel

An energy source formed in the Earth’s crust from decayed organic material. The common fossil fuels are oil, coal, and natural gas.

Fossil Fuel Levy

In England and Wales the Fossil Fuel Levy is set at 0.3%. This levy was introduced to cover the cost of decommissioning the nuclear generating plants. The Scottish equivalent is called the S.R.O. (Scottish Renewable Order) levy which was set at 0.8%

Fuel Cells

Fuel cells produce electricity from hydrogen and air, with water as the only emission. Potential applications include stationary power generation, transport (replacing the internal combustion engine) and portable power (replacing batteries in mobile phones).

Fuel Mix Disclosure (FMD)

The FMD regulations oblige all suppliers to calculate and publish the fuel source and emissions intensity of all the electricity they supply. This includes electricity generated by the supplier and electricity bought from other generators, either through contracts or in the marketplace.

Fuel Standardised Energy Savings

These are energy savings that have been adjusted according to the carbon concentration of each fuel. These coefficients are set out in the EEC Order and are as follows: coal 0.56, electricity 0.80, gas 0.35, LPG 0.43 and oil 0.46

Gas Act Owner (GAO)

The Gas Act Owner only relates to a meter. It is the Organisation or person responsible for providing installed metering for the measurement of gas consumption, and for maintaining the meter in good working order, as required by the Gas Act. The GAO may be Consumer, Supplier or Transporter.

Gas Substation

A pressure reduction station located on customers’ premises where gas is reduced from mains pressure regulated at a medium or low pressure for domestic or industrial use.

Gas Transporter (GT)

Responsible for maintaining a gas supply network. They may also be requested by the Supplier via the Shipper to provide a meter for the consumer’s usage. Requires a GT licence.

Giga Watt (GW)

Giga Watt – 1,000 MW.

Global Warming

The gradual increase in the average temperature of the Earth’s surface and atmosphere. The majority of scientists agree that the current warming we are experiencing is caused by the release of greenhouse gases from the burning of fossil fuels and other industrial processes.

Green Certificates

An official record proving that a specified amount of green electricity has been generated. Green certificates represent the environmental value of renewable energy production. The certificates can be traded separately from the energy produced.

Greenhouse Effect

The way gases in the earth’s atmosphere trap heat. The build up of these gases, especially carbon dioxide, are thought to cause global warming.

Greenhouse Gas (GHG)

A gas that absorbs infra-red radiation (i.e. the sun’s heat and energy) in the atmosphere. Greenhouse gases include water vapour, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), halogenated fluorocarbons (HCFCs), ozone (O3), perfluorinated carbons (PFCs), and hydrofluorocarbons (HFCs). These gases contribute to the ‘greenhouse effect’.

Greenhouse Gas (GHG) Protocol

A widely used standard for emissions reporting. The protocol covers project emissions reporting and corporate emissions reporting. The corporate emissions reporting standard provides a methodology for calculation of a carbon footprint. The protocol was developed by the World Resources Institute and the World Business Council for Sustainable Development.

Grid Supply Point (GSP)

The (GSP) is the point at which energy is taken from the National Grid transmission system into a local distribution system.

Grid Trading Master Agreement (GTMA)

A standardised agreement for trading UK power at the National Balancing Point.

Half Hourly (HH) Meters

A communication device connected to the meter allowing the data collector to remotely connects to the meter, obtaining half-hourly consumption.

Half Hourly Data (HHD)

HHD is the product of the half-hour data meter. The data is usually made available to end users by way of a spreadsheet. A full years’ half-hour data will be a spreadsheet with approximately 18,520 cells of data.

Half Hourly Meters

Since April 1998, code 5 meters have been mandatory for all sites over 100 kva, and voluntary for sites under 100 kva. This meter sends your consumption record by telephone or radio every half-hour to a central data bank. The supplier will then receive this information from the data collector and bill the client accordingly.

Hand Held Reads In Outstations

No comms installed, a meter reader will attend weekly to read the meter.

HDC Levy

HDC is a levy enforced by the DTI on all electricity suppliers across Great Britain. It is a tax that has been generated to assist areas with high electricity distribution costs.

Heat Rate

Energy input per unit of time, usually expressed in kWh\h or BTU\h

High Voltage (HV)

High Voltage (11,000 Volts or above).


Where a site consumes electricity as opposed to generating and exporting power. Import is the most common type of site.

Independent Public Gas Transporter (IGT)

An independent company who has responsibility of the maintenance of a gas supply network.

Infrastructure Costs

These relate mostly to the costs of providing the infrastructure required to deliver power. They include the cost of energy lost as heat as it travels from the power station down the transmission and distribution wires to you (which we call Tloss and Dloss), and charges for using the transmission and distribution networks (which are called TUoS and DUoS).

Kilovolt Amperes (KVA)

Also known as Total Power. The resultant effect of the active (kW) and reactive (kVAr) power is the total power measured in kVa. Kva = kW/power factor.

Kilowatt / Hour (KW / A)

A standard unit of electrical power equal to 1,000 watts. Kilowatts are the units used to measure Maximum Demand. Kilowatt hour is a unit of energy consumed.

Kyoto Accord

Agreed in Japan 1997 targets ‘carbon-rich’ gases and commits 38 industrialised countries to emissions cut of 5.2% by 2010.

Kyoto Protocol

In 1997, representatives from over 170 nations met in Kyoto, Japan to put together a new global treaty – the Kyoto Protocol to the United Nations Framework Convention on Climate Change (UNFCCC) – laying down legally binding reductions in greenhouse gas emissions throughout developed countries emissions by an average of 5.2 per cent below 1990 levels over the period 2008-2012.

Levy Exemption Certificates (UK)

Organisations that pay the CCL can enter into agreements with suppliers to purchase renewable electricity. The Levy Exemption Certificates (LECs) are evidence of CCL exempt electricity supply generated from qualifying renewable sources. LECs will be redeemed by suppliers to HM Customs and Excise to demonstrate the amount of non-climate change electricity able to be levied that had been supplied to non-domestic customers in the given period.

Line Loss Factor

Line Loss Factor codes are used to calculate the related DUoS charges for an MPAN. The figure gives us the voltage scale of the Mpan and reflects both the amount of transmission infrastructure used to supply the point and the amount of energy lost through heat etc


The amount of electric power delivered or required at any specific point or points on an electrical system. The requirement originates at the energy-consuming equipment of the customer.

Load Factor

Measures the relationship between unit consumption and maximum demand and is the percentage capacity utilisation figure of a site’s power consumption. To calculate load factor take the total number of units of consumption, divide by the maximum demand, divide by the number of hours in the period, and multiply by 100.

Load Management

Where sites are flexible as to when they use their electricity. This means that they can schedule their production and shift patterns according to the price of pool electricity. Consumers who can load manage are able to significantly reduce their consumption at the three times in the year when the National Grid takes the Triad maximum demand readings which are used to calculate the transmission charges.

Local Distribution Zone (LDZ)

Local Distribution Zone is a Transco defined area for which the total input and output demand can be measured each day.

Low Voltage (LV)

Low Voltage, normally at 240 or 415 Volts.

M Number Database

A web based application held by National Grid used by suppliers to view basic site details of sites not in their ownership. See xoserve.

Maximum Annual Quantity (MAQ)

Total quantity of gas to be delivered to the customer sites during the contract year. Usually defined in a Take or Pay clause.

Maximum Demand

Maximum Demand is the highest peak of usage (kWH) in any Half Hour during a calendar month or between two meter readings measured in either kW or kVA. This value is multiplied by 2 to give the MD on an hourly basis.

Mega Watt (MW)

Mega Watt – a measure of power, one million watts.

Meter Asset Manager (MAM)

A role that can be taken on by a number of parties who will manage a portfolio of meters on behalf of their client. They could control the meter replacement program, arrange Meter Work. The MAM will act as the point of contact for a meter point and can supply all known information regarding that meter point.

Meter Asset Provider (MAP)

The party responsible for the ongoing provision of the meter installation at that meter point. Where a MAP provides the meter, the MAM may be the owner (title owner) of the meter or the MAM could lease or rent the meter from a third party.

Meter Operator (MOp)

The organisation appointed to maintain metering equipment.

Meter Operator Charges (MOp Charges)

This charge covers the cost of maintaining metering equipment.

Meter Point Administration Number (MPAN)

An MPAN (Meter Point Administration Number) is 21 digits in length and should be printed in the format below on a recent electricity bill.

Meter Point Administration Service (MPAS)

Organisation that holds all information of MPANs.

Meter Point Reference Number (MPRN)

MPRN (Meter Point Reference Number) is the unique reference number for your gas supplies. They are unique to your property. You can find it on your gas bill.

Meter Serial Number

The number stamped on the front of the meter. This changes when meter is exchanged.

Micro Business customers


Gas: Consumes not more than 293,000 kWh per year; or
Electricity: Consumes not more than 100,000 kWh per year; or


Employ fewer then 10 employees (or FTE equivalent) and
Their annual turnover or balance sheet is not greater than €2 million

Million Cubic Meters (MCM)

1 MCM is approximately 360,000 therms.


Mega Watt hour, one thousand kWh. A 1 MW power-generating unit running for 1 hour produces 1 MWh of electrical energy

National Balancing Point (NBP)

The point where wholesale gas is traded within the UK.

National Grid

The National Grid owns the main transmission systems and is responsible for transmitting the electricity from the generator to the local RECs area. All electricity generated in mainland UK is put into the National Grid before fed into distribution networks.

Network Code (NWC)

The rules and procedures that govern the way National Grid and all shippers operate within the deregulated market.

New Electricity Trading Arrangements (NETA)

In England and Wales these arrangements replaced ‘the pool’ from 27 March 2001. The arrangements are based on bi-lateral trading between generators, suppliers, traders and customers and are designed to be more efficient, and to provide greater choice for market participants.


A notice to National Grid from a Shipper to indicate the request for the offer details for a supply point (transportation, metering, capacity, commodity costs, etc.).

Nomination Flow

A notice to xoserve from a Shipper to indicate the request for the offer details for a Supply point (transportation, metering, capacity, commodity costs, etc.)

Non Half Hourly (NHH) Meters

Unlike HH meter a meter reader must visit the site to obtain readings. There are different tariffs (SSC) available.

Non-Daily Metered (NDM) Supply Point

Volume of gas consumed at supply point is recorded at monthly, quarterly or longer intervals by traditional meter reading.

Notional Balancing Point (NBP)

NBP is where entry gas is brought to a virtual point in the system from which network users can transport to an exit point, thus becoming a trading hub.


A notice from XOSERVE to a Shipper in response to a nomination indicating the charges to be levied on a Supply Point.

Office Of Gas And Electricity Markets (OFGEM)

OFGEM is the government regulator for Gas and electricity markets.


Gas consumed by a site or customer.

Pass Through Charges

Charges that appear on bills to cover the costs of third parties involved in the energy supply chain to deliver power.

Peak Demand

Point of maximum electricity demand on the national system.

Percentage Day

This refers to the percentage ratio of electricity used in the daytime against that used in the night. This information is used by suppliers to quickly identify the type of profile.

Photovoltaics (PV)

The direct conversion of solar radiation into electricity by the interaction of light with the electrons in a semiconductor device or cell.

Power Factor

This relates to how efficiently electricity is used on your site. Certain types of equipment cause poor power factor which reduces the capacity of the network to supply power. Distribution Network Operators’ (DNO) can charge customers for this through power factor charges.

Public Registration System (PRS)

Used to register suppliers, meter operators and distribution companies for settlement purposes for all premises in the UK.

Reactive Charges

Charges applied to a client’s invoice in cases where certain suppliers and distribution companies enforce a penalty for Reactive Power use.

Reactive Power (KVAR)

This is the difference between the electricity supplied and the electricity converted into useful power. If the difference is large, i.e. there is a large amount of power being wasted, its puts an additional strain on the distribution network. The loss of power can be caused by kinetic energy (heat) or through defective machinery. This is measured via the Reactive register on a meter and is charged to the customer depending on how much they accumulate.


OFGEM is the Office of Gas and Electricity Markets, regulating the gas and electricity industries in the UK. This is a statutory body representing the interests of gas and electricity consumers in the UK.

Remote Non Half Hourly Meters

These meters have a NHH set up but they are connected to a communication device.

Renewable Energy

‘Renewable energy’ is used to describe the energy produced using naturally replenishing resources. This includes solar power, wind, wave and tide and hydroelectricity. Wood, straw and waste are often called solid renewable energy, while landfill gas and sewerage gas can be described as gaseous renewables.

Renewable Energy Certificates (REC’s)

RECs, also known as ‘Green Certificates’, green tags, or tradable renewable certificates, represent the environmental attributes of the power produced from renewable energy projects and are sold separate from commodity electricity.

Renewable Energy Guarantee of Origin (REGO)

Electronic certificate used to provide evidence that a unit of electricity has been produced by a renewable generator. One REGO representing one kilowatt/hour of electricity. In some countries they are called Guarantees of Origin – GoOs.

Renewable Obligation (RO)

This is the main government market mechanism to support renewable energy. It is an obligation on all electricity suppliers to supply a certain amount of their electricity sales from accredited renewable sources under the Climate Change Levy exemption scheme.

Renewable Power Association (RPA)

The Renewable Power Association is a trade association open to all companies supportive of the UK renewable energy industry.

Renewables Obligation (UK)

The new Renewables Obligation and associated Renewables (Scotland) Obligation came into force in April 2002 as part of the Utilities Act ( 2000 ). It requires power suppliers to derive a specified proportion of the electricity they supply to their customers from accredited renewable sources. This starts at 3% in 2003, rising gradually to around 10% by 2010 and 15.4% in 2015/16.

Renewables Obligation Certificate (ROC)

Eligible renewable generators receive Renewable Obligation Certificates (ROCs) for each MWh of electricity generated. These certificates can then be sold to suppliers. In order to fulfil their obligation, suppliers can either present enough certificates to cover the required percentage of their output, or they can pay a ‘buyout’ price of £34.30 per MWh (set by Ofgem for 2007-2008) for any shortfall. All proceeds from buyout payments are recycled to suppliers in proportion to the number of ROCs they present.

Service Industry Code (SIC)

The SIC is a standard classification code which identifies the types of business conducted at the site.

Settlement Agency Fee

Elexon, the UK’s Balancing and Settlement Code Company, charge for making sure all parties involved in distributing, supplying and measuring energy supply are paid appropriately.

Settlements Agency

This is the body that “settles” the distribution of electricity to establish where and to whom the generated load has been distributed to.


A shipper buys gas from producers / importers, transports this through the gas network by National Grid, and sells the gas to its customers. The shipper may have a contract directly with the customer, or may act on behalf of a 3rd party.

Smart Metering

The ability to remotely read non-half hourly (NHH) meters. Data is more reliable and more accurate bills are produced.

Standing Charge

Is a daily or monthly charge to contribute towards installation, maintenance and administration costs for the local Distribution Network Operator (DNO).

Sub Station

These play an important part of the national grid. They contain transformers which increase or decrease the voltage of an electric current.


The term often used when a property owner installs a separate meter to monitor the consumption of a utility such as water, gas or electricity.


A person authorised by a supply licence to supply electricity or gas to the National Grid Network, via the Shipper.

Supply Hourly Quantity (SHQ)

SHQ is the maximum hourly consumption for a supply point.

Supply Number

S-Number (also known as MPAN – Meter Point Administration Number). A unique number identifying the distribution company and the location of the metering point.

Take Or Pay

Percentage of gas purchased by the buyer from the seller against the Minimum Bill Quantity.

Tariff Structure

Suppliers quote for electricity in numerous different formats. These range from simple one-rated structures (the same price per kW at all times throughout the year) to complex “Seasonal Time of Day” tariffs which are multi-rated. i.e. the price changes three, six or eight times a day.

Temperature And Pressure

Gas either expands or contracts slightly under varying temperature and pressure. It is also known as the Conversion Factor and usually set at 1.02264. The Conversion Factor is taken into account when converting gas usage from volume to energy.

Thermal efficiency

Quantity of heat produced in relation to fuel input.


A unit of energy measurement. To calculate equivalent value in kWh, multiply by 29.3071.

Time Pattern Regimes (TPR)

Codes that state what date and time the meter registers start and finish.

Title (Meter) Owner

This is also referred to as Legal Title Owner. The person or Organisation to which the asset belongs, and that makes such assets available for the purpose of the Gas Act Owner.


Equipment that is used to change the voltage of an electric current. Transformers can increase or decrease voltage.


The transfer of electricity at high voltage from the power stations across the UK through wires on pylons to points where it can be distributed to users. This is known as the Grid System and is owned and operated by the National Grid Company (NGC).

Transmission Losses (Line Losses)

When transmitting electricity from generator to local distribution network areas some electricity is lost. Specific calculations have to be made by suppliers to determine the level of these losses.

Transmission Use of System (TUoS)

The charges are incurred for transmitting electricity across the National Grid network from the source of generation to the network of the local distribution company.The level of these charges is usually calculated by applying a rate charge to the TRIAD demand level.

Transportation Charge

A charge made by National Grid for the national transport of the shippers’ gas through the gas network (National and Regional Transmission system and the low and medium pressure distribution system) to the customer. The transportation charge consists of three elements, which are dependent on the locations of the particular terminal and offtake site: capacity charge; commodity charge; and site charge.


It is used to calculate TUoS Charges. The TRIAD is calculated by looking at the three maximum demand points (in kW) of the supply at half hourly time periods, and then averaging the total. The figures used are usually selected from winter months, and at peak times, as these periods are set to reflect the point at which the highest demand occurs on the National Grid.

UK Kyoto Target

Kyoto target – all greenhouse gases 12.5% below 1990 levels by 2008-12 National goal – CO2 20% below 1990 levels by 2010 Long-term goal – Reducing CO2 emissions by some 60% from current levels by 2050

UN Framework Convention on Climate Change (UNFCCC)

The international framework established in 1992 to tackle the issue of climate change and greenhouse gas emissions. The UNFCCC aims to prevent dangerous man-made climate change and commits developed countries to take the lead in tackling climate change.

Unit Price

The price per unit of energy which includes 3 components only – energy wholesale price (energy at NBP), infrastructure costs and a cost to serve element

Value Added Tax (VAT)

VAT is a government-imposed tax on the supply of goods and services.  There are currently 2 rates of VAT applicable to supplies of electricity and gas – the standard rate and the reduced rate. On supplies used solely for business purposes, VAT will usually be charged at the standard rate.

Where supplies are wholly or partly for domestic or charitable non-business use, that part of the supply qualifies for the reduced rate of VAT.  This is known as ‘qualifying use’.

Customers with qualifying use will need to submit a VAT Customer Declaration Certificate for each site, to advise us what percentage of the supply meets the qualifying criteria set by HM Revenue and Customs (HMRC).  Please note that VAT Declaration Certificates are not transferable between suppliers.


A unit used to measure the electromotive force of an electric current.

Voltage Scales

The Voltage Scale is not set by the customer, but determined by Networks when the premises supply is connected. Depending on what kVA is requested by the customer, and what Networks are faced with when installing the supply, will determine which voltage scale is required. The voltage scale can also be determined via the Line Loss Factor.

Voltage Transformer

A device that reduces (or increases) the supply voltage for example a 11000/415 Volt transformer would convert volt supply to 415 volt supply.


Xoserve, delivers transportation transactional services on behalf of all major gas transportation companies