Ofgem has approved new rules requiring NESO and electricity network operators to exchange detailed planning data more routinely from 6 August.

Grid Code modification GC0139 is intended to give the system operator and network companies a clearer view of electricity flows across the boundary between the transmission and distribution systems.

The change replaces parts of the existing annual submission process with a more structured, two-way exchange of solved power system models. These models will use the Common Information Model format, supported by updated data schedules and technical documentation.

Ofgem said the existing arrangements placed limits on the planning information exchanged between NESO and network operators.

The new process is designed to improve visibility of neighbouring networks and provide a more consistent basis for planning infrastructure across transmission and distribution boundaries.

That is becoming increasingly important as more wind farms, solar projects, batteries and smaller generators connect directly to local distribution networks rather than the high-voltage transmission system.

This distributed generation can make it harder for NESO to understand exactly how much electricity is being produced and consumed across Great Britain.

The decision comes amid wider scrutiny of NESO’s forecasting and operational visibility following pressure on the electricity system during June’s extreme heat.

A confidential report commissioned by NESO reportedly warned that the rapid growth of smaller and decentralised energy resources, was making it more difficult to calculate how much power was required to balance the system.

GC0139 was originally proposed by Electricity North West in February 2020 and was unanimously recommended for approval by the Grid Code Review Panel.

The change focuses on long-term planning rather than real-time control room operations but better network models could improve decisions on reinforcement, connections and future system needs.

It should also help operators understand how changes on one part of the network could affect another as Britain moves towards a more decentralised and flexible electricity system.

The new requirements will enter the Grid Code on 6 August.