National Grid to use flexible demand to manage voltage in 100 LV zones

National Grid DSO is preparing to use flexible electrical demand to help manage voltage constraints on the low-voltage network, as growing numbers of EVs and rooftop solar change power flows. 

Its new Local Voltage Management service will initially cover 100 LV zones across National Grid Electricity Distribution's four licence areas.

Rather than using the same intervention everywhere, National Grid intends to respond differently depending on what is driving the voltage problem.

In areas with high EV uptake, it will procure ‘Demand Turn Down’ between 17:00 and 19:00, allowing participating assets to reduce consumption during periods of higher evening demand.

In areas with high solar PV uptake, the DSO will instead procure ‘Demand Turn Up’ between 12:00 and 14:00 from May to August. That’s because increasing local electricity consumption during periods of strong solar generation can help absorb more power locally and reduce the risk of voltage rising outside permitted limits.

National Grid describes the service as a way of using flexibility to balance power flows and prevent voltage excursions, while testing whether market-based interventions can complement more traditional network solutions.

The approach could involve a wide range of controllable electrical assets. The DSO says that there will be no minimum asset size, with eligible technologies including batteries, EV charging, heat pumps and storage heaters.

Doerte Schneemann, Head of Flexibility Markets at National Grid DSO, noted, “This year’s tender marks an important step forward with the introduction of our first Local Voltage Management flexibility service. This new service gives us the opportunity to explore whether flexibility can help support voltage management on local networks and complement more traditional network solutions.

“We hope the insights gained will help shape the flexibility markets of the future and inform our thinking as we prepare for ED3.”

It’s no surprise to see National Grid DSO to begin using more flexibility, as Ofgem has decided that voltage management will become an explicit DSO responsibility under the next electricity distribution price control, ED3, which begins in April 2028.

The regulator expects network operators to improve their understanding and control of voltage conditions as increasing numbers of technologies such as EV chargers and PV inverters alter the behaviour of local networks.

National Grid's new service therefore provides an opportunity to test how far flexible demand can form part of that future operating model before ED3 begins.

It’s not the first time the DSO has used flexibility, of course. National Grid's previous long-term round resulted in 196GWh of flexibility contracts, with EV chargepoints accounting for the largest technology category by awarded availability volume.

The new procurement seeks a much larger 2.82TWh across 826 zones, including 99 HV zones and 727 LV zones. That puts the total potential market opportunity from the wider procurement at up to £4.6 million. The Local Voltage Management service itself will operate with a ceiling price of £200/MWh.

The DSO is also preparing a separate high-voltage voltage-management service, potentially from late 2026 or early 2027, which could involve the procurement of reactive power or power-factor adjustment.

The long-term tender opens on September 21 and closes on October 30. Successful providers are expected to be awarded contracts in January 2027, with services running from April 2027 to March 2028.