Impacts of NOAA GSL Research - Power Lines
How GSL’s HRRR weather model helps refine Dynamic Line Ratings for power lines, optimizing energy capacity and distribution
Power grids are lifelines that deliver energy to our homes, businesses, schools and beyond. The amount of power that can flow through (known as a line rating ) is meticulously planned and must fit a threshold in order to avoid risk of damage and fires. The line rating has major implications for energy efficiency. GSL’s HRRR weather models are becoming an important piece in planning Dynamic Line Ratings, maximizing energy distribution along power lines.
How it works
Power line condition can be affected by factors both inside and outside of the physical wire. The line rating is affected by air temperature around the line, wind speed and direction across the line, and solar radiation incident on the line.
Pushing too much energy through a power line can lead to too much heat generated, which can cause the line to sag towards the ground. If the line is too close to the ground, it can cause electrical arcing between trees or other structures, which can start significant fires. Sagging can also change the material property of the line, decreasing efficiency. Every power line is given a line rating, which determines the amount of current that can travel through a line without sagging.
The energy industry often uses one single static rating for each line, based on extreme values for the area. This, however, does not account for day-to-day meteorological changes and can lead to inefficient energy distribution.
Using Dynamic Line Ratings (DLR) refers to changing the amount of current pushed through power lines based on weather condutions. Accurate weather forecasts are key in making DLR effective and efficient. GSL's HRRR model helps provide the weather forecast to guide these decisions.
HRRR and DLR
GSL, in partnership with CIRA and CIRES, collaborated with the Department of Energy’s Idaho National Lab to evaluate the accuracy of using HRRR for DLR in South Idaho. The partnership worked to calculate the additional current that power lines can safely carry.
The study found that with HRRR weather forecasts, line ratings could be increased to 5-8% of additional capacity in a 1 to 16-hour range without exceeding safety margins. It also found that wind speed has the greatest impact on how much electricity can flow through.
Higher line ratings means more energy transmitted. Successfully designed Dynamic Line Ratings can decrease grid congestion and reduce curtailment (the deliberate decreasing of energy production due to transmission constraints). They also help save money in energy dispatch. HRRR weather forecasts are key in improving DLR and optimizing clean energy usage.
Next Steps
Future work aims to look at specific line orientations and use cases as well as consider site thresholds to inform DLR. Researchers will also examine cost savings achieved by using DLR to maximize energy distribution.