Overview
Project Description
Key Research Question
Managers of overhead distribution systems are frequently challenged to improve system performance, manage a fleet of aging assets, and deploy new technology that is expected to perform for decades. Emerging technologies can offer opportunities to improve performance, but utilities lack objective performance assessments. Because total replacement of aged assets is impractical, utilities must strategically plan resources to best maintain system reliability while promoting safety, reliability, and environmental stewardship.
The Overhead Assets project investigates new designs and approaches for overhead assets, asset degradation and failure, inspection methods, and emerging technologies to enhance component reliability, longevity, and cost-effectiveness. Asset managers can use the test data generated by the research to make informed decisions about selection, installation, inspection, maintenance, and replacement.
Objective
Utilities strive to design, construct, and maintain overhead distribution systems that can reliably withstand extreme weather and harsh conditions for decades. However, asset managers often face challenges due to insufficient information, leading to decreased reliability and increased operations and maintenance (O&M) expenses.
Our research aims to evaluate the performance of overhead distribution equipment and hardware, assess inspection tools and technologies, and document best practices to help utilities enhance the reliability, resiliency, and service life of overhead assets. Additionally, we aim to capture and disseminate knowledge regarding overhead asset design and application through guides, videos, and training materials.
Approach
This project employs well-documented and repeatable laboratory testing, field studies, and demonstrations to inform overhead distribution asset lifecycle decisions. This project also facilitates knowledge sharing among participants to accelerate the adoption of leading utility practices. Key planned research tasks include:
Planned 2026 Research
This project conducts material and structure testing, evaluates inspection tools and technologies, and documents leading practices to inform overhead asset life-cycle decisions. The 2023 project includes the following tasks:
Resilient Structure Design: Characterize dynamic loads on a distribution structure caused by a falling adjacent structure based on line variables such as span length, line tension, and conductor weight. Structure designers can use the collected load data to design overhead lines that arrest cascading structure failures and improve overall resilience. In 2026, the intent is to focus on creating cascade-like events in a laboratory environment and characterizing the resulting loads on adjacent structures.
Alternative Pole and Crossarm Material Evaluation: Examine the performance of alternative materials such as composites, steel, ductile iron, and concrete. In 2026, EPRI plans to investigate the electrical performance of crossarms in salt-contaminated environments. EPRI also plans to continue investigating the aging characteristics of composite materials.
Overhead Connector Performance Testing: Test the electrical and mechanical performance of connectors under varying conditions to prevent outages. In 2026, EPRI plans to develop an approach to age and assess aged corrosion inhibitor compounds. Additionally, EPRI plans to subject connectors to short circuit tests.
Assessment of Conductor Performance and Emerging Materials: Review new and aged conductor performance and explore advanced conductors like high temperature, low sag (HTLS) to accommodate increased loads from electrification. In 2026, this research aims to investigate the performance of covered conductor technologies.
Evaluation of Emerging Transformer Technologies: Analyze aged transformer performance and evaluate new designs and monitoring technologies. In 2026, we will focus on emerging transformer designs, including the latest solid-dielectric transformer technology.
Evaluation of Pole Inspection Technologies: Pole condition assessment provides a means of prioritizing pole replacement to better optimize O&M budgets and minimize failures during storms. This task investigates tools used to assess the health of distribution poles of all types of materials. In 2026, this task intends to collect nondestructive inspection results for comparison with utility-collected traditional groundline inspection data.
Grid Monitoring Technology Assessment: Test grid monitoring systems and inspection tools to identify outage precursors and assess overhead asset health. In 2026, we will help utilities evaluate new technologies through controlled lab tests, including vegetation encroachment and equipment degradation.
Visual Inspection and Condition-Based Monitoring: Research the relationship between distribution component health and visual data such as imagery, video, LiDAR, and other digital data. In 2026, we will continue to explore the use of cameras on utility vehicles and drones for continual inspection and O&M reduction.
Technology Scouting: Scout new technologies for overhead distribution and identify opportunities for further investigation and demonstrations. The pace of change in distribution technology is accelerating, and we aim to stay ahead by exploring innovative solutions.
Research Value
Overhead distribution asset managers and standards engineers can leverage our test results to make informed decisions throughout an asset’s lifecycle. Applying this information can:
- Enhance Procurement Specifications: Improve the criteria for selecting new assets
- Inform Asset Selection and Installation: Ensure optimal choices and proper installation techniques
- Enable Effective Inspection Technology Application: Utilize advanced tools for accurate assessments
- Optimize Inspection and Maintenance Cycles: Establish efficient and effective maintenance schedules
Overhead Distribution (P180.001) Deliverables & Value Propositions
|
2025 Result |
Value |
Drivers |
||||
|---|---|---|---|---|---|---|
|
Reliability |
Resiliency |
Capital Project Support |
O&M Cost Management |
Modernization |
||
| Anti-Cascading Structure Investigation | Optimize structural design to improve resiliency | |||||
| Alternative Pole and Crossarm Material Evaluation | Enables intelligent selection of pole material and manufacturer | |||||
| Overhead Connector Performance Testing | Reduce risk of interruptions caused by degraded and failed connectors through improved connector specs | |||||
| Assessment of Conductor Performance and Emerging Materials and Technologies | Identify options to increase distribution line capacity, suchs as using high-temperature, low-sag conductor | |||||
| Evaluation of Emerging Distribution Transformer Materials and Technologies | Improve transformer specs to maximize long-term system reliability | |||||
| Evaluation of Pole Inspection Technologies | Ability to prioritize replacement and repair based on objective inspection data | |||||
| Online Condition Monitoring of Overhead Systems | Lab testing of new online monitoring systems that provide situational awareness | |||||
| Visual Inspection and Condition - Based Monitoring | Improve value,accuracy, and processing speed of inspection data | |||||
Task Force
This task force consists of utility subject-matter experts in areas related to overhead line construction, materials, and standards. The task force is focused on the life-cycle of overhead assets including poles, crossarms, conductor, line hardware, arresters, cutouts, wildlife protection, and more. This task force meets several times per year by WebEx or in person. There is usually one in-person meeting per year held in conjunction with the other P180 task forces.
Members are encouraged to participate in several ways:
- Attend task-force meetings
- Provide equipment for testing or evaluation
- Provide information on your utility’s standards or practices (a survey for example)
- Review and comment on reports and findings
- Attend testing at EPRI laboratories
- Present to the task force on utility issues or initiatives
- For equipment failures, submit equipment to EPRI for forensic analysis
- Reach out to Joe Potvin on matters related to overhead distribution assets
This task force is also a good opportunity to meet and network with overhead distribution asset experts from other utilities.
Common Questions
Who can attend task-force meetings?
- Task-force meetings are for funders of the overhead assets project (P180.001). This includes task-force members and guests from sponsoring companies.
Are there specific membership requirements?
- The only requirement is to fund the overhead assets project (P180.001). There are no meeting attendance requirements. However, members find that they get the most value when actively participating in the research.
How do I join this task force?
- Just send a request to Joe Potvin. Similarly, if you’d like to be removed, let one of them know.
Can my company have more than one task-force member?
- Yes and is encouraged to do so.
Can I share task-force material within my company?
- Yes and is encouraged to do so.
Can I share task-force material outside my company?
- Generally, not. There are exceptions, so if you have a need, please contact Joe Potvin.
Are discussions covered by a non-disclosure agreement?
- Yes. All EPRI member agreements include non-disclosure clauses.
If my company isn’t funding this, how can I sign up?
- Each company has their own methods for selecting components of the annual EPRI research portfolio. Contact your METT for more information. Technical advisors from EPRI’s member services can also help. Find contact information here.
Related Research
- Impact of Electrification
- Assessment of AQ as a Woodpecker Deterrent
- Vehicle Impacts on Utility Poles
For more on supplemental projects, see here. To discuss project ideas, contact Joe Potvin.
Implementation Opportunities
Supplemental projects can also be one-on-one efforts. Companies allocate their self-directed funds in different ways. Options for these projects can include:
- Field pilots of technologies
- Integration of research results
- Teardowns of failed equipment
- Test specific equipment or scenarios
Examples related to current research could include:
- Full-scale structure testing, mechanical or electrical
- Implementation of online condition monitoring technologies for identifying abnormal system conditions
Services and Capabilities
EPRI has several capabilities available to utilities as part of research work, supplemental projects, or service agreements:
- Arc-flash testing of equipment
- Forensics and material analysis of equipment failures
- Custom tests of fuse cutouts, arresters, transformers, or other overhead line equipment
- Mechanical and electrical testing of full-scale distribution structures
- Evaluation of online condition monitoring equipment
Other Programs
EPRI research related to overhead distribution assets is found in several other areas.
Program 1: Power Quality
Program 1 has leveraged power quality data to identify electrical system issues, including approaches to detect degraded and failing distribution assets. This information is helpful as utilities try to improve situational awareness to prevent outages before they occur.
Program 51: Transmission & Distribution: Environmental Issues
Program 51 examines environmental issues related to distribution and transmission infrastructure. Recent research has investigated the environmental impact of wood poles treated with DCOI, as well as advanced methods of detecting hazard trees in right-of-ways. P51 is also collaborating with the overhead assets project on wildlife guard research.
Program 60: Electric and Magnetic Fields and Radio-Frequency Health Assessment and Safety
This program considers environmental health and safety issues related to public and worker exposure to electric and magnetic field (EMF) and radio frequency (RF) environments associated with electric power system infrastructure.
Program 180: Distribution Systems
Equipment failures can often pose safety risks. Worker safety technologies and practices are investigated in the distribution safety project (P180.004). Research considering wood pole failure rates that can help with future capital planning can be found in the Asset, Reliability and Resiliency Analytics project (180.005).