An Unmetered Supply is provided for electrical equipment where either it is not practical to install a meter and/or the cost of installing a meter is disproportionate to the cost of electricity used by the equipment. Typical unmetered equipment is street lights, traffic signals, illuminated signs and bollards but can also include telecommunication cabinets, CCTV, advertising displays and Electrical Vehicle charging.
Certain conditions apply before equipment can be connected to an electricity distribution system without a meter recording consumption. The main condition is a requirement for the consumption to be logically estimated with a reasonable degree of accuracy and charged to the customer through their appointed electricity supplier.
The legal provision for an unmetered supply is defined by the Electricity (Unmetered Supply) Regulations. The Office for Product Safety and Standards has issued guidance on interpretation of the Regulations.
The Unmetered Supplies Operator (UMSO) is a role defined by the electricity industry to ensure the arrangements for unmetered supplies are correctly applied. Each electricity network operator appoints an UMSO who will:
An accurate inventory of unmetered equipment is based on trust, but the National Terms of Connection enable an audit regime which is defined further in Managing Unmetered Energy Street Lighting Inventories (MUESLI). The MUESLI document also outlines the process for correcting any identified errors with the inventory.
There are two types of electricity network operators, Independent Distribution Network Operators (IDNO) and Distribution Network Operators (DNO). The 14 DNOs cover 14 defined geographic areas of the country. IDNOs have introduced competition into the distribution of electricity and operate across the country. IDNO networks are often referred to as Embedded Distribution Networks because they are generally embedded within a DNO’s network.
