Daily meter (dm) 

A Daily Meter Supply Point that has a yearly consumption of more than 58,600,000kWh (2,000,000 therms per year), will have a mandatory data logger fitted to record, store and transmit daily readings and measurements. A daily meter is recorded every day.

Non-daily metered (ndm)

A Non-Daily Metered Supply Point has its consumption read on a monthly, quarterly or longer basis.

Data Aggregator (DA)

A Data Aggregator (DA) aggregates the metering data from the Data Collector (DC) and provides this into the balancing and settlement process.

Data Collector (DC)

A Data Collector (DC) is an agent appointed to retrieve and validate your metering data. The data they collect is sent to the Data Aggregator (DA).

Distribution losses

Distribution losses are charges related to energy losses in the distribution system that occur as it is transported from the grid to your meter. They are revised annually in April by the Distribution Network Operator (DNO).

Distribution use of systems (duos)

A Distribution Use of System, or DUoS, charge is included in a business’ electricity invoice to cover the cost of supplying their electricity through their supplier’s regional network.

What a duos charge covers

DUoS charges cover the cost of receiving your electricity from the national transmission system and feeding it directly into your business through the regional distribution networks. It covers the costs of installing, operating and maintaining the regional distribution network, to ensure a safe and reliable electricity supply.

Duos availability charges (or kva or supply capacity)

This is the charge for the power capacity held available for a supply point, its charged in £/kVa/day whether you use it or not. If the capacity is breached and excess availability is used, this is chargeable as an excess availability capacity charge. It’s important that you set your kVA at the correct level, so you do not pay for capacity that you don’t need. You can contact your local Distribution Network Operator (DNO) directly to discuss your kVA requirements.

Duos excess capacity charge

The DUoS Excess Capacity charge is levied by the DNO when the monthly maximum demand exceeds the agreed DUoS Capacity.

Duos reactive charges

This is the measure of ‘non-working’ power. Some electrical equipment, typically motors and transformers, require reactive power to function effectively. Reactive power is chargeable if it exceeds limits set by the DNO. If your site has a poor power factor (ratio of active power to reactive power), it is possible to mitigate these costs by installing Power Factor Correction equipment.

Distribution use of system (duos) unit charges

The traffic light DUoS charges (green, amber, red and super red) relate to different periods of usage on the network and their associated unit rate prices. They will vary depending on whether it’s a weekday, weekend or the time of the day itself. Green band charges are incurred during periods of lower demand, for instance, evenings and weekends. Amber band charges apply to weekday daytime. Red band charges are incurred during peak periods of demand such as between 4pm and 7pm on a weekday. Super red charges are rare and only apply to Extra High Voltage (EHV) sites.

What is a distribution network operator?

Your distribution network operator (DNO) is the company that owns and operates the power lines and infrastructure that connects homes and commercial properties in your area to the electricity transmission network. They can help you with queries such as moving your meter, connecting your property, or with a power cut.

Visit the Energy Networks Association website to find out who your network operator is. Find out more about your Network Operator’s standards here.

Domestic or non-domestic supply

A Supply Point with an AQ of 73,200 kWh (2500 th) or less, is deemed as a domestic site. It’s important to note that this does not necessarily mean a residential site. A supply point with an AQ of over 73,200 kWh is deemed as non-domestic.


Electricity charges

Non-commodity electricity charges are added to an electricity invoice by the government and third parties such as distribution companies. There are a variety of non-commodity charges attached to electricity.

Electricity market reform (emr)

The Electricity Market Reform (EMR) is a significant piece of government policy designed to improve affordability, reduce carbon emissions and keep the lights on. Key elements of EMR include Contracts for Difference (CfD) and the Capacity Market (CM).

Elexon fee

The Elexon fee recovers the running cost of Elexon. Elexon administers the Balancing and Settlement Code (BSC) and provide and procure the services needed to implement it.

Energy Intensive Industry (EII)

Visit our dedicated page, to find out more about Energy Intensive Industry (EII)

Excess capacity charge

See DUoS Excess Capacity Charge.