dno

DNO is an acronym that most commonly stands for Distribution Network Operator. In the electricity sector, a DNO is the licensed entity responsible for operating and maintaining the local electricity distribution network that carries power from the national transmission system to homes and businesses. Distribution networks are typically regional and cover low- and medium-voltage levels, up to around 132 kV, including substations, cables, and transformers. DNOs also handle customer connections, disconnections, and the integration of distributed generation and demand-side resources.

Role and responsibilities include ensuring safety and reliability of supply, carrying out network planning and reinforcement to meet demand, and coordinating fault responses and outage management. They work with the national Transmission System Operator on system balancing and with local authorities on safety and planning issues. DNOs also manage the process for new connections and set terms for connection agreements, facilitating the connection of customers, installers, and distributed energy resources such as rooftop solar or small wind installations.

Regulation and performance are overseen by the national regulator Ofgem, under price-control regimes such as RIIO-ED1 and RIIO-ED2. DNOs have defined service standards and revenue allowances, and they publish performance data (for example, SAIDI and SAIFI) to monitor reliability and customer service. In Great Britain, there are several geographically defined DNO license areas, reflecting the historic regional structure of the electricity market, though corporate arrangements have evolved over time.

Note: DNO can have other meanings in different sectors; this article focuses on the Distribution Network Operator in the electricity industry.

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