Unlocking grid potential: The power of dynamic line rating
As electricity demand rapidly rises across the country, utilities are under pressure to quickly expand affordable, reliable, and resilient power.
Adding new power generation and transmission infrastructure will play a critical role in addressing this challenge, but utilities will also need to squeeze every last amp out of their existing infrastructure. Dynamic Line Rating (DLR) offers a promising opportunity by optimizing the capacity of power lines based on real-time weather conditions.
Traditional line ratings use conservative assumptions about the amount of electricity that can safely flow through them. But line ratings change based on weather conditions such as temperature, wind speed, and other factors. Lines can transmit more electricity in certain weather conditions, which means the traditional approach to line rating can result in unused capacity.
Using sensors that attach to transmission lines, DLR is a technology that can unlock additional capacity by adjusting the amount of electricity that can safely flow through power lines based on real-time weather conditions.
For example, a strong wind can cool transmission lines, which allows them to transmit more electricity. The presence of even a mild wind can add 20% to a line’s capacity. But wind blows at different speeds and directions depending on the time and location on any given day, as seen in this example in Figure 1. DLR can detect which lines have increased capacity due to the wind.
Figure 2 shows a hyperlocal example of specific transmission lines that can carry additional capacity when cooled by wind blowing perpendicular to the lines. Wind has a reduced cooling effect when it blows parallel to transmission lines.
To understand the value proposition of DLR, we conducted studies to help determine cost-effectiveness and provide an estimate of how much capacity can be unlocked by using this technology. We found that DLR is significantly less expensive (~$500K on average) than having to either build new lines or upgrade old ones (typically $1M per mile, plus time). Additionally, studies have shown that DLR typically increases capacity during ambient conditions that exist 94% of the year in a midwestern climate.
Key benefits of DLR for utilities
1. Enhanced affordability
Traditional line ratings use conservative assumptions, often leading to underutilization of transmission capacity. DLR, on the other hand, leverages real-time data to unlock additional capacity, allowing utilities to transmit more electricity without the need for costly infrastructure upgrades.
As asset management and capacity utilization are intrinsically linked, ICF helps utilities identify where exactly their transmission lines are and better understand how to more accurately charge customers based on how much electricity can be pushed through their lines, given fluctuations of temperature and other weather conditions.
2. Improved reliability and resilience
By providing real-time insights into transmission line conditions, DLR helps utilities manage load more effectively, preventing overloads and reducing the risk of equipment degradation. This proactive approach enhances the reliability and resilience of the power grid.
3. Regulatory compliance
DLR supports compliance with regulatory requirements such as FERC Order 881, which mandates the use of ambient-adjusted ratings to improve transmission line capacity utilization. By adopting DLR, utilities can meet and exceed these regulatory standards with real-time optimization.
Utilities need to have a deep understanding of regulatory requirements to meet FERC and NERC standards, helping them stay ahead of regulatory changes and navigate the complexities of compliance.
Where to put all those DLR sensors
The U.S. has approximately 640,000 miles of transmission, of which over 200,000 miles is in the bulk electric system (100kV and above). Adding DLR sensors to every line would be costly. By analyzing historical weather patterns and projections of future weather patterns, utilities can identify the specific power lines that offer the greatest opportunity for optimization with DLR sensors. This highly targeted approach to DLR can simultaneously increase affordability, reliability, and resilience.
ICF is one of the only organizations integrating LiDAR, asset mapping, line impedance, and climate domain knowledge into predictive capacity calculations. We leverage our in-house scientists, engineers, and technology to examine historical weather patterns, determine future weather patterns, and better understand where DLR is most economical for utilities.
Ultimately, the integration of targeted DLR technology can offer utilities a key asset to help address growing electricity demand while delivering affordable, reliable, and resilient power.