Transmission and
Distribution Asset Inspection
The power grid in the United States is generally comprised of generation, transmission and distribution for public and private use. Generation is comprised of hydroelectric, solar, wind turbines, geothermal, biomass and fuel based steam generation power plants. From there the power is sent to substations and then to transmission and distribution lines. A major issue confronting the utility companies is the aging of the assets with a large percentage of transmission lines, structures and transformers being well over 30 years in age. A continuous effort is underway to maintain and modernize assets.
Working in close proximity to high voltage and at heights is hazardous. Ground navigation to poles or structures in difficult or distant terrain can cause damage to vehicles, personal injury and in rare instances, loss of life. In certain locations the only way to inspect poles or structures is with Human External Cargo (HEC) which is a high-risk endeavor for the line persons and helicopter pilots.
In most instances drones are able to simply fly to a pole or structure and take high resolution imagery (stills or video) providing complete photographic coverage of a pole or structure from all angles. Experience has shown that the cost to have a drone inspect a pole or structure is at minimum 50% less than a climbing visual inspection thus providing an excellent ROI. A simple ground only photographic inspection will not reveal all components or overhead views necessary for a complete inspection. Linear photographic inspections by helicopters cost thousands of dollars an hour in helicopter operation costs with the associated limitation of inability to capture imagery of crucial components underneath the helicopter’s vantage point. This is in addition to potential liability for high-risk, low level helicopter operations in close proximity to terrain and obstacles.
Inspection and Inventory
The aerial imagery capture of a pole or structure is preplanned and generally involves an aerial circular rotation around a pole or structure at different levels and camera angles with photographic overlap of sectors to ensure complete and clearly focused and exposed photographic coverage. The photographic coverage should include all hardware components, equipment, insulators, conductors and the overall condition of the structure itself. While at asset locations, care should be taken not to disturb wildlife or create any type of environmental impact.
Oftentimes poles or structures are tagged with erroneous identification markings, are missing tags or have inaccurate GPS coordinates. In some cases an asset isn’t on a utility company’s list of assets. In a few rare circumstances a pole or structure is simply not where a utility company thinks it is (eg “ghost structure”).
Drones are capable of providing accurate GPS coordinates which is recorded within the metadata of the imagery provided to the client or customer. Obvious significant defects or integrity problems of an asset can be reported immediately from the field for the prompt generation of a work order and remediation of the issue.
