Dynamic Line Rating (DLR)
Overview
Dynamic Line Rating (DLR) is a technology that enables real-time assessment of power transmission lines’ ampacity, considering varying weather conditions to enhance grid reliability, efficiency, and stability. By continuously monitoring environmental factors and applying thermal models, DLR systems calculate the maximum safe current a transmission line can carry at any given moment, optimizing line utilization and deferring or eliminating the need for costly infrastructure upgrades.
Benefits
Below are a few of the primary issues that DLR can be leveraged to address:
- Rising Peak Demand: DLR allows operators to maximize line utilization during peak demand periods and reduce congestion on the grid.
- Aging Infrastructure: Real-time ampacity information helps operators better balance line loading compared to simple seasonal ratings. This helps reduce thermal stress on the conductors and can extend their useful life.
- Intermittent Generation: DLR enables more efficient use of existing infrastructure, facilitating the connection of remote, variable renewable energy sources.
Technology Readiness Level (TRL): 8
DLR technologies have been demonstrated in laboratory settings, pilot projects, and deployed in utility in-house developed implementations. Some commercial solutions are available, but widespread adoption is still limited. Assessment: TRL 8.
Adoption Readiness Level (ARL)
Value Proposition
Delivered Cost
Medium Risk
Installing, connecting, and setting up all the equipment and software could be associated with significant costs. This represents a large upfront capital cost where the payoff is roughly understood but perhaps not great enough to encourage first movers yet.
Functionality Performance
Medium Risk
DLR systems have demonstrated accuracy in real-time ampacity calculation and robust performance under varying environmental operating conditions. Depending on the method used, sensors would need to be periodically recalibrated to avoid inaccurate readings which could be costly, time consuming, or impacted functional performance negatively.
Ease of Use/Complexity
Low Risk
DLR systems are well developed and automated, which has resulted in limited retraining requirements. Staffing will likely not be a limiting factor to adoption.
Market Acceptance
Demand Maturity/Market Openness
Medium Risk
DLR technology provides a clear benefit to utilities and provides a more robust solution relative to static line rating. However, the risk associated with upgrading the transmission system is always large and the default action by utilities is to not disturb the status quo. Or, at a minimum, not be the first one to do so until the technology is further derisked.
Market Size
Low Risk
Technically all transmission across the US could use DLRs and therefore the market could be the entire grid. The value it brings is dependent on the types of environments the transmission sits within (weather, congestion, etc.).
Downstream Value Chain
Low Risk
Areas in the grid that suffer from strict regulatory hurdles (i.e., expansion projects are legally challenging) and large amounts of congestion will have the shortest payback period. Areas with no grid congestion may take much longer to receive a return on investment for a DLR system.
Resource Maturity
Capital Flow
High Risk
Until utilities have an opportune moment (such as building new transmission) it is unlikely DRL becomes a priority for capital deployment and therefore additional investment will be needed from other sources to spur adoption.
Project Development, Integration, and Management
Medium Risk
The technology has been implemented, but not broadly. Subsequently, more projects are needed to truly prove out the success rate and convince movers that this technology can be delivered on time and on budget.
Infrastructure
High Risk
DLRs are, by nature, a large infrastructure project where whole sections of transmission are upgraded to additional equipment. Sensors, monitors, information relay, and control will be needed along all lines which would be a large scale. This would also require upgrades to the control rooms that manage transmission.
Manufacturing and Supply Chain
Low Risk
DLR solutions primarily rely on sensors, data acquisition systems, and communication networks, which are widely available and have established supply chains.
Materials Source
Medium Risk
Some of the materials needed for sensors and electronic components have an inherent geopolitical risk associated with their acquisition. Rare earth metals, semiconductor materials, special alloys, etc.
Workforce
Low Risk
The workforce for DLR development and deployment consists of power system engineers, data scientists, and communication specialists. While qualified professionals already exist in the market, utilities may face competition from other industries for qualified personnel.
License to Operate
Regulatory Environment
Low Risk
No regulatory barriers specifically prevent the use of DLR technologies in power grid systems. It is possible that some risks appear from a regulatory standpoint around performance (will the DLRs work exactly as advertised without unintended, negative consequences) but this is unknown.
Policy Environment
Low Risk
Federal, state, and local policies support grid modernization, reliability, and resilience. However, utilities may be cautious in adopting new technologies due to concerns about potential disruptions and the need to maintain high system reliability.
Permitting and Siting
Low Risk
DLR solutions primarily involve the installation of sensors and communication equipment, which typically have minimal permitting and citing requirements. Transmission has already undergone permitting, Upgrades to it is likely this a relatively easy and timely process.
Environmental & Safety
Low Risk
Very little to no environmental or safety risks associated with upgrading lines and operating rooms.
Community Perception
Medium Risk
Communities will likely support grid modernization from a reliability standpoint. However, the increased cost to rate payers will never be well received. It’s likely that some pushback will appear due to the costs associated with this upgrades.
Case Studies & Implementation
PG&E’s Dynamic Line Rating Program
Pacific Gas and Electric (PG&E) has implemented DLR on over 1,500 miles of its transmission lines, resulting in an average 10-15% increase in line capacity and improved reliability during peak demand periods.
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