Dynamic line rating, or DLR, uses sensors and data analysis to continually monitor transmission lines. This avoids the need to set conservative, static values to line capacity, increasing power carrying capacity by 8% on average. This reduces the need for constraint payments, where a generator is paid to stop generating to avoid overloading the electricity network.
The expansion of DLR across National Grid鈥檚 network follows eight years of testing and expansion with US-based DLR provider, LineVision. Following the successful implementation of DLR technology on National Grid鈥檚 US networks in New York and Massachusetts, National Grid ran a two-year trial on a 275kV transmission circuit between Penwortham and Kirkby in Cumbria between 2022 and 2024.
With the trial complete, dynamic line ratings will be deployed under a new five-year contract across an additional 585km of key north-to-south transmission routes, potentially saving consumers up to 拢50m.
Installations will take place across three network boundaries (in the North East on 345km of overhead line, in the Humber area and East Anglia covering an additional 240km) with further planned over the five year period. This additional rollout means that 39 circuits, covering over 900km of National Grid鈥檚 transmission network, primarily key north to south power flow routes, will now have the technology installed.
This work is being completed in partnership with three companies, LineVision, Ampacimon, and Heimdall, through a five-year contract. This establishes a trusted base of suppliers to develop and deploy DLR systems, accelerating the speed and scale of the rollout of the technology. The majority of installations are expected to be complete by 2028 and will be delivered through a variety of different solutions, including using drones to mount sensors to live power lines, avoiding the need to wait for planned outages of key transmission routes.