November 30, 2017
High-resolution wind, temperature, and solar flux forecasts could help utilities operate more efficiently and cost-effectively by increasing the amount of electricity that transmission lines can safely carry.
Utilities place thermal limits (ratings) on transmission lines to avoid excessive sag from high temperatures, loss of strength, or failure of the line. These ratings provide the operator with the overhead transmission line’s capacity to carry power safely at any moment.
In partnership with the Department of Energy’s Idaho National Laboratory, researchers from the Global Systems Division (GSD) and the Cooperative Institute for Research in the Atmosphere (CIRA) evaluated the accuracy of NOAA’s High Resolution Rapid Refresh (HRRR) forecasts against observations of temperature, wind speed and direction, and solar flux from 45 weather stations in southern Idaho. They also calculated the additional electric current a conductor could safely carry in different weather conditions.
Using a basic approach with HRRR forecasts, researchers found dynamic line ratings (based on actual weather conditions) could be raised to potentially achieve 5-8% additional capacity without exceeding safety margins in the 1-16 hour range. They also found wind speed is the primary meteorological variable that affects how much electricity can safely flow on transmission lines. Next steps will be to look at specific line orientations and use cases, and consider site-specific thresholds to develop more sophisticated approaches that could be used for dynamic line ratings.
For more information contact: Susan Cobb 303-497-5093