The Need For Power Grid Inspections
Above ground Transmission and Distribution (T&D) power grids deliver utility power across the country. The Infrastructure is exposed to all that weather has to offer, 24-7-365. This is hard on equipment and that equipment needs to be inspected on a regular basis to make sure it is in good condition.
It is important that all sections of the above ground power grids operate in an optimum manner, but as climate change and extreme weather cycles have started to take their toll on states and regions, additional attention has to be focused on areas with high voltage and a substantial amount of dry fuel, as that combination and faulty equipment has recently generated some of the largest wildfires in US history. These areas are generally rural, low population density, difficult to access and from a wildfire point of view are known as Tier 3 fire zones.
Up to recently the inspection process for these overhead assets would involve one of 2 primary methods.
1) Ground based inspection, a team of inspectors made up of multiple staff would travel to the towers, view, inspect and photograph the tower, in some cases climb the tower and take images of the tower/pole condition.
This involved heavy trucks gaining access to the tower, sometimes across private property, with multiple staff and heavy equipment, it is a slow process and leaves a substantial footprint.
The images captured were from a ground or on the steel prospective and this meant that some angles/frames were unavailable.
It is also an elevated risk inspection as staff are climbing towers and poles and operating in close proximity to energized power lines.
2) Helicopter based inspection, a high voltage electrical inspection crew would be flown by helicopter over a circuit, would make a visible inspection and obtain some images while underway and record tower condition.
This was/is a noisy slow process, most camera angles below the top of the tower are difficult to get as it puts the helicopter too close to overhead lines.
The increased standoff makes the photography more challenging also.
It is also an elevated risk inspection as it adds additional moving parts with staff in the air to the inspection equation.
Both options are expensive but the work needs to be done.
Enter drone technology and its suitability for transmission and distribution powerline and equipment inspections.
Drones are Cost Effective & Improve The Inspection Process
New Inspection Process – Overview
Split the inspection process into two sections, data collection and data review, this will improve efficiency, reduce footprint onsite, reduce time onsite on each asset and turn all inspections into low risk operations.
Drone Field Team
One or two man teams, with equipment and transport to access the asset, make contact with the customer as needed, complete a comprehensive image collection of the tower/pole and surroundings for context based on a predefined shoot list. Climbing is not required, most cases you don’t even need to be close to the asset. Time on site is greatly reduced, impact on site is greatly reduced and risk factor is reduced by an order of magnitude. (This makes insurance companies very happy)
The drone teams are not electrical workers, although they have training on how to operate and fly in the vicinity of high voltage lines and this is built into our field SMS/SOP.
Office Review Team
The images by pole are supplied to the office team, there they are reviewed by (TEW’s) Trained Electrical Workers, who are familiar with the subject matter, based on that review the assets can be signed off as inspected and added to the next rotation schedule or if there is an issue, a lineman crew can be dispatched to repair.
The above is a high overview of the process, but what it does demonstrate is a much more efficient use of staff, where scarce and expensive resources (TEW’s) are used to make needed repairs rather than inspecting multiple assets, the majority of which are in good working order. This is further multiplied when you are dealing with large quantities of towers and poles that are involved with larger utilities.
Project Deliverables – Collection
The details on deliverables will vary by project but you can expect a starting point of
- A set of images (usually JPG) organized by circuit & structure ID.
- Average number of images per asset will depend on specific project requirements.
- Images in sufficient detail from required angles that an offsite reviewer can review and determine the condition of the asset. (as per project specifications).
- Inspection will be on energized lines with no Interruption in service required.
- Images will be time & date stamped and provide a visual record of the asset condition at that time.
- Images will be of consistent quality across all assets.
- Collection process will occur inside specific agreed operational guidelines.
So how do you design, plan and execute an inspection project at small or large scale, enter a specialized drone services company.
Drone Services Company
The drone inspection process for above ground Transmission & Distribution (T&D) grid involves new and evolving technology and work practices. You the utility, do not need to have a large staff of drone pilots, equipment and support staff on the payroll, you need a drone services company with considerable Inspection experience which can undertake the project on a turnkey basis and supply the volume of trained crew and equipment you need when you need them, for contracts large and small.
Images can be collected from above, level with and below towers, poles, crossarms, equipment & conductors at 360 degrees and also include vegetation and wildfire clearance shots so that it is only necessary for one team to visit the tower to collect the required information. It should also be noted that due to vegetation, buildings, construction not every asset can be shot entirely by drone and for these cases all our field teams are supplied with ground cameras to help us complete the inspection process.
The complexity of these projects varies, Laguna Drones can undertake projects on a turnkey basis or assist with any aspect of design, planning and/or execution as well as integration with existing utility processes.
As the saying goes “when you have met one utility, you have met one utility” we realize that each utility has its own work practices, terminology and procedures, we work with stakeholders internal and external, as well as your preferred contractors to integrate the collection and inspection process best practices and flight safety guidelines into your operations.
- Design project to integrate with utility work practices.
- Design a custom drone shoot list specific to your project.
- We recruit staff required from our list of experienced personnel.
- Collection staff equipped with specific drones and safety equipment.
- You have final approval via your staff on-boarding process.
- Laguna Drones manages the field work inspection process as a turnkey operation.
- We integrate feedback channels into the collection & review systems for maximum efficiency.
- Agreed image folders supplied by Pole/Tower ID for review by your staff.
- Review and sign-off complete and project complete.
Laguna Drones has invested and continues to invest considerable time and money into our SOP’s for flight operations and data collection.
Sometimes these SOP’s have to be modified to become specific project SOP’s to take into account specific utility procedures and as long as risk mitigation factors remain in place at an acceptable level then we can make these accommodations.
We operate our MAD (minimum approach distances) for energized lines based on FERC/NERC drone testing guidelines which vary with voltage.
We like every other commercial drone company operate under CFR Part 107 rules and our collection process and daily field operations are designed around that.
Laguna Drones has been involved in some very large inspection projects involving large utilities with integrated aviation wings and records from these utilities have shown that incidents per flight hour for drone flights are an order of magnitude less than manned aviation.
The next steps – near future
Technology in this area ( as in most areas) is constantly evolving. The next steps in this inspection process are evolving in two main areas,
a) Image Review
AI ( or artificial intelligence) has been brought to bear on the image review process, with the aim of perfecting a system where the initial review process is undertaken by software and it then determines whether all is in order or the image needs further review ( by a human). This way you will not need staff to review all images, you will only be supplied flagged images for further investigation. This will cut down a large percentage of the review work and the data bottlenecks that can occur on these projects.
Laguna Drones is currently working with 2 software providers on this system at the R&D stage and so far the results are promising.
This will need some hardware as well as regulation improvements before we have full adoption of this in the US. Beyond visual line of site is primarily an R&D project for part 107 users at the moment. In time this will allow for longer distance flights and will improve the speed of the data collection process.
The above is a general overview of the services provided by Laguna Drones, a specialized drone services company, focused on transmission & distribution power line inspections. We would be more than happy to assist with your utility inspection projects and if you would like to discuss further or see some detailed results, please contact us by phone or email.