National Grid Expands Smart Technology to Increase Capacity on Existing Power Lines

National Grid is rolling out advanced monitoring technology across hundreds of kilometres of its electricity transmission network in an effort to increase grid capacity without building large amounts of new infrastructure.

The company has confirmed a major expansion of Dynamic Line Rating (DLR) systems across England and Wales under a new five-year programme. The technology will be installed along an additional 585km of transmission routes, mainly covering key north-to-south electricity corridors. National Grid estimates the upgrade could save consumers up to £50 million by improving the efficiency of the existing network.

Dynamic Line Rating technology works by continuously analysing the real-time condition of overhead power lines. Instead of relying on traditional fixed operating assumptions, the system uses live data from sensors and weather conditions to determine how much electricity can safely pass through transmission lines at any given moment.

By providing more accurate operating information, DLR allows the network to safely carry more electricity than under older static rating systems. National Grid said the technology can increase transmission capacity by an average of around 8%, helping reduce congestion and lowering the need for costly balancing payments made to electricity generators when the network becomes overloaded.

The latest installations will take place across several strategic regions, including the North East, Humber and East Anglia. Once completed, the technology will be active on 39 circuits covering more than 900km of the transmission network.

National Grid said the rollout forms part of a wider programme of grid-enhancing technologies designed to modernise the UK electricity network and support growing demand driven by electrification and renewable energy generation. Other initiatives include advanced power flow control systems, artificial intelligence tools to help balance energy demand, and drone-based inspection technology for maintenance and monitoring activities.

According to the company, DLR systems installed during the current RIIO-T2 regulatory period have already helped save around £21 million in network constraint costs while contributing to more than 16GW of additional transfer capacity across the grid.

National Grid Electricity Transmission President Alice Delahunty said the technology would help unlock additional capacity on the existing network and support the wider integration of renewable energy supplies. She added that smart grid technologies are playing an increasingly important role in delivering a more resilient and lower-carbon electricity system.

The rollout is being delivered in partnership with technology companies LineVision, Ampacimon and Heimdall Power under a long-term framework agreement. Many installations are expected to use drones to fit monitoring equipment directly onto live overhead power lines, reducing disruption and avoiding the need for planned outages.

Industry partners involved in the programme described Dynamic Line Rating as one of the quickest and most cost-effective ways to unlock additional network capacity while helping accelerate the transition towards cleaner energy systems.

The expanded deployment follows several years of testing and trial operations, including pilot schemes in both the United States and the UK. After successful trials on transmission routes in Cumbria between 2022 and 2024, the technology was extended to additional circuits across northern England in 2025 before this latest large-scale rollout announcement.