Electricity supply networks are organized hierarchically. There are low-voltage networks, medium-voltage networks and high-voltage networks. While the latter are designed for overland transmission, medium-voltage networks supply larger industrial customers and large regional utilities, and low-voltage networks, as distribution networks, supply end consumers in a regional area.
Distribution networks are operated, serviced and maintained by distribution network operators (DSOs). They supply customers directly with three- phase electricity. The distribution network operators receive their electricity from the substations, from other distribution network operators or also from end consumers who feed their electricity into the network. This can be electricity from renewable energy, from wind turbines, biogas plants, hydroelectric plants or photovoltaic plants. Battery banks or neighborhood storage facilities can also be connected to such a low-voltage distribution network as energy buffers. The exchange of energy with other distribution network operators ensures the stability and reliability of the supply voltage.