Urban network development [distribution networks]

The UK´s rural electricity distribution network has never been in better shape. It has benefited from a decade of regulatory inspired attention and investment that has seen overhead lines refurbished, modernised and rebuilt to reduce faults and boost performance. Urban systems, in contrast, have never been in such a poor state as assets age and investment is diverted to rural areas. Urgent steps are required to address asset ageing before serious public safety problems start to arise. The size and nature of the problem, together with the implications for disruption to essential infrastructure, mean that early action is required. The Regulator must be persuaded that price cuts and supply quality are not the only issues facing the industry; maintaining public confidence in safety critical systems should become a high priority. Two possible solutions are described (distribution automation and voltage controlled protection-VTm), though others undoubtedly exist. Automation provides a flexible solution that builds on existing technology but has little beneficial impact on important safety critical systems. A key disadvantage concerns the increase in operating costs associated with telecommunications and IT infrastructure, and this is only likely to be economic if required for other purposes. VTm is a new system but nevertheless it is likely to prove reliable as a result of its basic simplicity. Its main weakness is the requirement to install new switchgear and protection systems and this also, paradoxically, happens to be its greatest strength.