National Grid’s Distribution System Operator (DSO) has secured what it says is its biggest long-term flexibility portfolio to date, awarding 196GWh of flexibility availability through its latest annual tender.

The tender round, which National Grid DSO said closed in November, expands the volume of flexibility it has contracted to help manage constraints on the distribution network – a role that is becoming more important as electrification increases and more renewable generation connects at local level.

Cathy McClay, Managing Director of National Grid DSO, noted, “This year’s results show real momentum behind flexibility as a smarter, more efficient way to operate the electricity network and ultimately drive down costs for consumers.

“We’re delighted to have delivered our largest long-term tender yet and to see such a positive response to our new Flex Up service. It’s a strong foundation as we continue to expand and evolve our local flexibility markets.”

National Grid DSO said the 2025 tender round introduced wider availability windows and more service hours, increasing the scope for participation. The company added that more than 4.5 million customers are located in flexibility zones, broadening the pool of potential flexibility providers – from large assets down to smaller distributed technologies aggregated across multiple sites.

While National Grid DSO’s headline figure is 196GWh, the actual results give a clearer view of what sits underneath that total.

Electrical Review’s analysis of the published trade results indicates the bulk of the awarded ‘availability’ volume comes through high-voltage products combining scheduled availability with day-ahead operational utilisation, accounting for around 143GWh in the latest round. A further 52.6GWh sits within ‘DTU/GTD only’ variants of the same product family – broadly aligning with National Grid DSO’s statement that its new demand turn-up service, FlexUp, saw 52GWh awarded across 23 high-voltage zones.

The published results also point to a technology mix that is increasingly shaped by flexible, low-carbon demand.

Across the awarded portfolio, EV charge points represent the largest single category by awarded availability volume, followed by broader site demand flexibility, solar and storage. Fossil gas assets also appear within the accepted mix, but at a materially smaller share of the total than EV charging and other low-carbon categories – underlining how flexibility is increasingly being delivered by electrified loads and distributed resources rather than conventional plant.

National Grid DSO also highlighted that further opportunities remain in the short-term market, which is transitioning from a week-ahead to a day-ahead procurement model. The shift is intended to bring flexibility purchasing closer to real network conditions, and to make it easier to match local constraints with assets able to respond at shorter notice.