Closed distribution networks, according to European regulations, are those that supply electrical energy to an industrial area. They allow adding small consumers with different network voltages as if they were a single large consumer connected to a higher voltage.
Only industrial companies belonging to category B or C of the National Classification of Economic Activities (CNAE) and those still belonging to groups D and E are counted as industrial for statistical purposes, may form a closed distribution network. Up to 100 non-industrial consumers may participate in the network, as long as they are related to industries, are inside the network or are adjacent to it, and do not represent more than 2% of total electricity consumption.
The industrial owners of the closed network will have to build it or buy it from a distribution company, and will be responsible for managing it, investing in its maintenance and billing for tolls, charges and other costs to connected consumers to it, while marketers who sell electricity to members of the closed network will only bill for the energy consumed.