National Grid works with Met Office to unlock capacity on overhead power lines

National Grid Electricity Transmission has teamed up with the Met Office to unlock spare capacity on its overhead power lines by incorporating more precise weather forecasts into the calculation of line ratings.

The partners are aiming to leverage advances in weather forecasting and integrate a cloud-based forecasting service into National Grid’s existing dynamic line rating methodology as part of a new innovation project.

As well as its physical properties, the capacity of an overhead power line is also dependent on weather conditions such as wind speed and direction, ambient temperature and solar radiation, which determine the amount of cooling provided by the surrounding environment.

However, the ratings for individual circuits have historically been calculated based on conservative assumptions for weather conditions, meaning the assets have been operated at below their actual capacity. National Grid said incorporating more precise weather forecasts into its dynamic line rating methodology will allow it to push more power through the lines when conditions are favourable for cooling.

Anusha Arva, innovation engineer for National Grid, said: “We’ve explored the feasibility of integrating high specification weather forecasting data into our overhead line rating calculation methodology along with starting the initial work towards a demonstrator system.

“We’re now looking to take the research forward through a subsequent phase of innovation, with the aim to validate this updated methodology against measurements from specific sections of the transmission network, using devices such as local weather stations, and overhead line measurement sensors.

“The specific sections of the transmission network will be chosen based on a range of scenarios under which dynamic line rating methodology would need to operate, with focus on sections shaded by dense vegetation and civil structures.”

“With the knowledge and expertise from the Met Office, more accurate and granular weather data can better determine where and when we can boost capacity. Inevitably, this means we can become less reliant on fossil fuel-based generation, avoiding constraint payments to generators when we need to address grid congestion.”

Ian Pearman, senior scientist for the Met Office, added: “With electricity generation increasingly dependent on the weather, we’re working ever more closely with National Grid.

“This innovative project has the potential to provide significant improvements in weather forecast accuracy for the energy sector alongside novel approaches to quantifying uncertainty in the forecast. These can be applied to increase confidence in uprating decisions to help achieve the flexibility requirements on the path towards net zero.”

The Dynamic Line Rating project is being supported with £545,000 of funding from Ofgem’s Network Innovation Allowance.