The Technical Consultant

Glossary of Terms

Availability Charge
A charge for the amount of power made available to the customer’s property, it is expressed in £/kVA and relates to the contractually authorised supply capacity (ASC).

Power delivered at a flat rate throughout a specified delivery period i.e. March baseload.

Bid Price
The price at which a buyer is prepared to purchase a given volume of a commodity.

Climate Change Levy – a tax on the business use of energy – applicable to gas, electricity, coal and LPG.

Combined Heat and Power – a highly efficient technology for generating electricity and heat in a single process.

Carbon Dioxide - a Greenhouse gas.

Connection Agreement
Agreement between client and the local distribution company (for example Central Networks in the Midlands) setting out the terms and conditions with which each are bound concerning the provision and use of the connection.

Data aggregator – the organisation appointed to aggregate collected data received from the appointed DC, also responsible for calculating distribution lines losses.

Data collector – the organization responsible for collecting, processing and validating meter data, estimating non-half hourly consumption and passing information to the DA.

The interruption of supply, so that electricity cannot flow from the network to the premises.

The requirement for power/gas.

The permanent removal of the meter, cabling and service from the property once it is established that a supply will not be required in the future.

Distribution System
The local wires, transformers, substations and other equipment used to distribute and deliver energy to consumers. The system is low voltage – 132kV and below.

Distribution Use of System - the charges incurred by suppliers for distributing electricity across the local area system to the supplied premises.

Estimated Annual Consumption - a projection of annualised consumption for a customer without half-hourly metering. It is derived from profile information and the latest meter advance.


Grid Supply Point – a point of supply from the national transmission system into a local distribution

Gigawatt hour – a unit of energy consumption equal to 1,000,000 kilowatt hours or 1,000 megawatts hours. 1 GWh is equivalent to the total electricity typically used by 250 homes in one year.

Half-Hour Data - this is the product of half-hour data meter, which records and stores data for each half hour period throughout the day. The data is then used for invoicing, tendering and reporting purposes and is mandatory for all users above 100kW demand.

High Voltage - Normally exceeding 1,000 Volts.

Interruptible Gas
Gas supplied to a customer on the basis that the supply might be interrupted for a specified period. The site will have an alternate fuel source and generally incurs a lower charge for transportation.

Kilovolt Amperes – Unit of Apparent power. Used by electrical engineers to rate equipment as this measure takes into account both active and reactive energy.

Kilowatt – a standard unit of measure of power equal to 1,000 watts (103) or to energy consumption at a rate of 1,000 joules per second.

Kilowatt hour – unit of energy consumption, equivalent to 1kW of power expended for 1 hour of time. A typical home uses around 3,300 kWh of electricity per annum.


Line Loss Factor – the factor used to calculate the losses in the distribution network lines.

Low Voltage – normally exceeding 50 volts, often 240 or 415 Volts.

One million cubic feet – commonly used as a measurement of gas.

Maximum demand – the highest average demand (in kW or kVA) registered in a half hour period throughout a month. The annual MD is the highest recorded in any half hour period during the year.

Measurement Class (see also Profile Class)
A code indicating the method of measuring electricity usage for a particular supply.

Meter Operator - the organisation appointed to install, maintain and remove metering equipment.

Meter Point Administration Number – a unique identifier for the supply to a particular address. It is divided into two parts, the MPAN Core (a 13-digit number forming the bottom line of the Supply Number) and the supplementary data (an 8-digit number on the top line). 

Meter Point Reference Number - a unique reference number identifying each meter (gas) and used in the preparation of supply tenders.

Megawatt – a standard unit of measure of power equal to 1,000 kilowatts.

Megawatt hour – a unit of energy consumption equal to 1,000 kilowatt hours.

Top of page

National Grid
Previously National Grid Transco, National Grid own, operate and develop the high-voltage electricity transmission network in England and Wales and Great Britain's principal natural gas transportation system.

National Balancing Point – a notional point on the UK gas or electricity system through which all gas/electricity pass for the purposes of balancing and accounting.

New Electricity Trading Arrangement – came into force in March 2001 to replace the Pool system. A market based mechanism in which bulk electricity is traded forward through bilateral contracts and on exchanges as other commodities. Covered England and Wales, excluded Scotland.

Network Code
The hub around which the competitive gas industry revolves, comprising a legal and contractual framework to supply and transport gas. In 2005 as a result of the sale of four of the gas distribution networks by NGT, the Network Code was replaced by the Uniform Network Code (UNC).

Offer price
Also referred to as the Ask price – refers to the price at which a seller is prepared to sell a given volume of a commodity.

Office of Gas and Electricity Markets - responsible for regulating the Gas and Electricity Supply Industries in England, Wales and Scotland.

Public Electricity Supplier.

Profile Class (see also Measurement Class)
Profile classes are used for non half-hourly metered supplies providing the electricity supplier with an expectation as to how electricity will be consumed throughout the day.

Power factor
This is the measure of how effectively electricity is being used on a site. Certain types of equipment cause poor power factors, which reduces the capacity of the network to supply power. Distribution companies will charge customers for this through reactive power charges. 

Reactive Power Charges
Reactive Power is measured by the Distributor and billed to the Supplier. Charges will depend on the Power Factor at a site. 

Renewable Energy
Energy derived from resources that are regenerative. This includes solar power, wind, wave, tidal and hydroelectricity. Wood, straw and waste are often called solid renewable energy, while landfill gas and sewerage gas can be described as gaseous renewable.

Standing Charge
A daily, monthly or quarterly charge levied by the local distribution company.

Supply Agreement
A contract between a supplier and the customer to supply energy at an agreed tariff or method for an agreed duration.

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.

The Carbon Trust
The Carbon Trust is an independent, not-for-profit company, which was created by the UK government to help business and the public sector cut carbon emissions.

A unit of measurement for gas, equivalent to 100,000 British Thermal Units (BTUs) or 29.3071 kWh.

A static electric device consisting of a single winding, or two or more coupled windings, used to transfer power by electromagnetic induction between circuits at the same frequency, usually with changed values of voltage and current.

The transfer of electricity at high voltage from the power stations across the UK to the local distribution networks. Known as the Grid System, it is owned and operated by the National Grid (NGT).

TUoS Charges
Transmission use of system charges – raised by NGT to suppliers for their use of the high voltage national grid transmission network.


CTM Logistics