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Industry Jargon Explained

As part of our commitment to providing a transparent service we have created a jargon buster for you. If you have spoken with energy suppliers or consultants you may have come across these terms before

Industry Jargon Phrases - R to Z

Reactive Power

Created when current and voltage are not in phase, measured in var and also known as apparent power

RECs (Regional Electricity Companies)

The pre-privatisation era description of monopoly regional energy businesses e.g. MEB, now nPower or EMEB, now E.ON


The process in which a consumer’s existing supplier applies for an MPAN/MPRN by 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.


Ofgem, the non-customer facing industry regulator responsible for the competitive energy market, a non-ministerial government department reporting to DECC


Where the consumer’s existing supplier rejects the switch of supply during the registration window

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


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


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


Embedded generators releasing surplus energy to the ‘grid’ to take advantage of price opportunities as a traditional generator would


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


How natural gas is measured on the wholesale market. 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

Transmission Network

The wires and pylons that carry electricity from generators to the distribution networks. Owned and managed by National Grid


The charges for and process by which gas and electricity is delivered from the generator to the meter point


The entity, primarily National Grid Transco, that transports gas from the producer to consumers


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


A volt is electrical pressure

Wholesale Market

The energy market where suppliers, generators, traders and customers purchase electricity and gas via bilateral contracts or through energy exchanges


Xoserve is the Central Data Service Provider for Britain’s gas market. They provide a comprehensive range of critically important services to gas suppliers, shippers and transporters it is jointly owned by the five major gas distribution Network companies and National Grid’s gas transmission business, Transco.

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