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glossary of energy terms

The energy world can be a mine field of jargon and acronyms, which, combined with the difficulty of deciphering your energy bill can push even the most patient person over the edge!

Our Energy experts have compiled a handy glossary to help guide you through the most common Energy terms. 

  • 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)

AQ 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. Clients 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).

  • 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 (KVA)

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 or KVA. 

  • Climate Change Levy (CCL) 

CCL is a Government imposed tax to encourage reduction in gas emissions and greater efficiency of energy used for business on non domestic purposes. CCL is chargeable only on units/kWh used and not on any other component of the bill, e.g. standing charge.

  • COT 

Change of Tenancy.

  • Distribution Network Operators (DNO) 

Companies 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.

  • EAC 

Estimated Annual Consumption (electricity usage).

  • Feed in Tariff (FiT)

FIT payments are made on a quarterly basis (at least) for the electricity your installation has generated and exported. Payments are made based on the meter reading you submit to your energy supplier (we call them your FIT licensee). FIT payments are made by your energy supplier from the date you become eligible for the scheme.

  • Half Hourly (HH) meters

A communication device connected to the meter allowing the data collector to remotely connect 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.

  • 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.

  • 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.

  • 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.

  • 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.

  • 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 Service (MPAS) 

Organisation that holds all information of MPANs.

  • Meter Serial Number (MSN)

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

  • MPAN

Meter Point Administration Number (electricity supply ID).

  • MPR

Meter Point Reference (gas supply ID).

  • MTC

Meter Time-switch Code – second three digits of MPAN.

  • MWh

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

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

  • Pass Through Charges 

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

  • Photovoltaic (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 clients for this through power factor charges.

  • Reactive Charges 

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

  • Renewables Obligation (RO)

The Renewables Obligation is the main support framework to incentivise the construction and generation of large-scale renewable electricity in the UK. The deadlines for application for new generating capacity has now closed however as electricity users this non-commodity charge will continue to make up part of your energy bill.

  • Shipper 

A shipper buys gas from producers/importers, transports this through the gas network by National Grid, and sells the gas to its clients. The shipper may have a contract directly with the client, 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).

  • 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.

  • 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 client. The transportation charge consists of three elements, which are dependent on the locations of the particular terminal and off take site: capacity charge; commodity charge; and site charge.

  • 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.

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