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.

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).

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.

Carbon Reduction Commitment (CRC)

The CRC is a UK government emissions trading scheme for large organisations which are not eligible for EU Emissions Trading. This includes banks, large offices, universities, large hospitals, large local authorities and central government departments. The scheme is mandatory.

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 (CCA)

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 supplier.

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.

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.

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

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

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.

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.

Fuel Mix Disclosure

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.

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.

Half Hourly Data (HDD)

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.

High Voltage (HV)

High Voltage (11,000 Volts or above).

Independant Public Gas Transporter (IGT)

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

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 (KWH)

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.

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 e

Low Voltage (LV)

Low Voltage, normally at 240 or 415 Volts.

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 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 (MPAN)

Supply Number or S-Number, is a reference number used to uniquely identify electricity supply points.

Meter Point Reference Number (MPRN)

Is a reference number used to uniquely identify gas supply points.

Meter Serial Number

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

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.

Non Half Hourly (NHH) Meters

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

Office of Gas and Electricity Markets (OFGEM)

OFGEM is the government regulator for Gas and electricity markets.


This is a new mandatory regulation which affects the way all electricity suppliers settle electricity consumption for businesses within a specified energy use. This will result in sites being migrated from non half hourly meters (NHH) to half hourly meters (HH), and enable suppliers to produce more accurate bills.

Pass Through Charges

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

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.

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.

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.

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).

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

A contract provision obligating the buyer to pay for a certain minimum quantity of product, whether or not the buyer actually takes that quantity during the stated period. Under a take-or-pay clause, the minimum amount of product that the buyer is obligated to pay for whether or not the buyer actually takes that amount of product, usually stated in terms of an absolute quantity, or a percentage of total contract quantity, over a specific period of time, usually a year.


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

Transmission Use of Systems (TNUOS)

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.