IET Voltage Management first report for Ofgem
The IET has agreed to undertake a study for Ofgem regarding emerging concerns over the adequacy of grid voltage management.
At the kick-off meeting with Ofgem on 19 Aug 2025, it was agreed that an IET Voltage Management Task & Finish Group (TFG) would be formed and work towards producing a position paper that would meet the following objectives:
- Define the scope of voltage management concerns.
- Explain the risks and opportunities.
- Explore the current policy context.
- Explore the extent to which the British 50Hz synchronous system might become exposed to a failure mode similar to that which led to the Iberian Peninsula event on 28 April 2025.
- Provide a roadmap of what is possible and realistic in the short and longer term.
This purpose of this interim report is to update Ofgem on the TFG’s progress to date. The report summarises the TFG’s analysis which suggests that a programme of enhanced active voltage management is now both possible and necessary in order to:
- Address current and emerging system operational issues;
- Reduce costs to customers directly through ensuring electrical appliances are operating within a supplied voltage range that enables efficient use of electrical energy;
- Increase grid hosting capacity for low carbon technologies (LCTs) in support of Clean Power 2030 and longer-term energy decarbonisation objectives in support of Net Zero;
- Improve overall grid efficiency in terms of effective voltage control, efficient asset utilisation, and economic management of system losses (hence indirectly reducing costs to customers).
- Increase overall system resilience to shocks arising from displacement of synchronous generation with weather-dependent inverter-based resources (primarily wind and solar generation).