Thermal Imaging Inspections for Electric Utility Equipment

by: 5 min read

In this article:

  • How thermal imaging sensors capture complete and accurate data
  • Thermal imaging capabilities for inspections
  • Thermal imaging use cases for overhead transmission and distribution lines


Proactive thermographic inspections are a crucial component of a utility’s asset management program. They help identify and mitigate malfunctioning equipment and issues contributing to line loss before more major service interruptions occur. Utility asset managers understand that equipment failures and service interruptions are much more costly than having a preventive maintenance plan that includes proactive inspections. Over time, changes in weather, load characteristics, changes in materials, and overall equipment condition will put added strain on the most vulnerable points in the electrical system. The heat signature of failing components and equipment is easily observed with an infrared (IR) sensor yet are normally invisible to the naked eye. Thermographic inspections are a cost-effective solution for utilities to fill the gaps left by visual-only inspections.

Clearsight is a leader in thermographic inspections of overhead electrical lines. Our crews receive utility-specific hands-on training and certifications in thermography as standard prerequisites. Leveraging drones as a vehicle, our crews are empowered to safely capture thermographic data on your system, fully energized under load, with no risk of electrical contact. The data captured from the field is inspected live by our crews and high-quality, actionable reports are delivered via our client portal.

Related Reading: 6 Key Insights to Help Utilities Evaluate Companies Using Drones to Inspect Electrical Assets

Thermal Imaging Capabilities

Thermography has been around for quite some time, but in recent years drone manufacturers saw an opportunity to invent sensors specifically for small, unmanned aircraft. Since drones can navigate the environment with minimal resistance, we can now help utilities inspect their overhead lines from a new perspective and deploy tools, such as infrared (IR) sensors, which were much too costly in the past.

IR sensors are central to any thermography inspection service. But not all IR sensors are created equal. High-resolution IR technology designed as payloads for drones and for the most demanding applications is becoming highly functional and useful for overhead line inspections. Here are a few benefits of our IR technology:

  • Helps improve the efficiency of inspections and keep costs lower.
  • Immediate temperature visualization – our inspectors can easily set parameters based on operational temperature thresholds that will highlight anomalies which stand out on the digital display so they can quickly identify hotspots.
  • Measuring temperature gradients – operators can isolate the utility asset to measure the lowest, highest, and average operating temperatures under load.
  • Seamless user interface – our operators can quickly switch between the camera and IR sensor, which empowers you to bundle inspections into one trip to the facility.
Thermal imaging technology allows for the identification of hot spots on utility poles that would be otherwise invisible to the naked eye.
Proactive thermographic inspections are a crucial component of a utility’s asset management program, helping to identify and mitigate equipment failures before they occur.

How Thermal Imaging Can Help You Maintain Your Electrical Equipment

Electrical grids are a complex system of hardware, components, and equipment constructed at various points in time spanning vast distances. Even the most modern systems built with advanced technology and engineered to withstand the test of time have weaknesses that can be exploited without a thorough inspection program. Some of the most reliable systems in the country are older systems that have been proactively maintained. A thorough inspection program including thermography can help utilities mitigate risks of failing equipment.

Here are examples of how that comes into play:


Maintenance of high-voltage transmission lines is crucial, because failure can affect a massive downstream consumer base: communication networks, banking infrastructure, manufacturing plants, healthcare systems, businesses, and residential consumers. While under load, failing electrical equipment and components share a common characteristic: high temperatures caused by excess electrical resistance. Thermal imaging is ideal for detecting these issues because inspections can be performed safely while the system is under full load.


Thermographic inspections can help utilities to mitigate the risks of failing equipment by detecting temperature gradients and identifying hotspots on utility poles.

Distribution systems account for the highest number of thermographic anomalies we find. The combination of varying operating voltages and changes in construction standards with changing load-mix over time leads to invisible vulnerabilities that are often undetected until a failure occurs. IR sensors empower us to proactively seek out thermal anomalies.

Thermal imaging can detect areas of high resistance or signs of leaking current. Some common failures areas include lightning arrestors, switch blades, 2 and 4 bolt pads, jumpers, compression fittings, and hot line clamps. Regular inspection schedules combined with baseline temperature measurements can detect anomalies and help with trending changes.

Bottom Line

Clearsight is a trusted partner to utilities across the nation because of our comprehensive drone-based inspection services centered on a proven methodology specific to electric utilities. We offer an industry-leading complete inspection service including data collection, processing, analysis, and reporting.

With our innovative processes and actionable inspection reports, your teams have all the data they need to improve system reliability and resiliency. Contact our team today to learn how Clearsight’s services can help you reduce the cost of asset ownership and achieve better results than the competition.

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  • Learn what it takes to implement a safe, efficient and sustainable robotic inspection program focused on delivering key insights for improving system-wide safety and reliability.







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