How Aerial Imagery Services Can Help the Utility Industry Deal with Natural Disasters  

 

Oct. 2011 MA Nor'Easter

More recently, when reporting on the October 2011 freak snow storm in New England, Boston's NECN TV quoted U.S. Senator Scott Brown (R-MA):

 

"I'm concerned, if it's tree limbs down on the wires, what's the tree trimming policy? Is there one that's up and running?  Has it been implemented? Because I travel around not only Wrentham, but the surrounding areas, and see a lot of the trees are literally either on the wires or very close and they should be trimmed down if we're going to every storm have this type of problem."   

 

 

[Source: ["Senator Brown Questions Storm Preparation."]   

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Unfortunately, most people outside the Utility industry do not realize that, nationwide, the utility companies annually spend millions of dollars on vegetation management. In fact, the North American Electric Reliability Corporation (NERC) requires companies within its purview to keep a documented plan. NERC is certified by the Federal Energy Regulatory Commission to establish and enforce reliability standards for the bulk-power system.

This standard also provides that each Transmission Owner shall have systems and procedures for documenting and tracking the planned vegetation management work and ensure that such work was completed according to work specifications. This results-based standard is based on input and research from the Utility industry. Two of the more prominent examples, as reported by the NERC, are:

On November 3rd, 2011, NERC approved "Project 2007-07 Vegetation Management" (FAC-003-2), a results-based, foundational standard that provides a defense in-depth approach to vegetation inspections, establish minimum clearance distances and provides that "a Transmission Owner shall create and implement an annual plan" for vegetation management work.

1. "Duke Energy's aerial patrols of the Roddey line, in which vegetation was apparently overlooked by the observer according to a Settlement Agreement. Because of the duration of the alleged violation, the SERC Reliability Corporation determined that the clearance between the vegetation involved and the Roddey White line conductor on August 22, 2007, could have been between 2 and 7 feet and was there for "some time." Given the extent of this encroachment into the minimum 15 foot clearance zone and the timing of the outage in August 2007, NERC believes it is reasonable to conclude that the encroachment constituted an enforceable alleged violation of standard FAC-003-1 beginning at least as early as June 18, 2007, the date the standard became mandatory and enforceable. This violation cost the company a $50,000 fine and other ongoing costs." [Source: NERC Notice of Penalty Regarding Duke Energy Carolinas, LLC, FERC Docket No. NP09-000, P. 7.] 
   
      
2. "A patrol completed on the Stuart-Atlanta line on June 25, 2003, by a helicopter service and using an AEP Transmission Line Mechanic, identified no vegetation- related problems. Fifty days after this aerial patrol, on August 14th, the outage occurred on the Stuart-Atlanta 34.5kV line from tree/conductor contact. It appears that the tree(s) that caused the August 14 outage should have been identified during the preceding aerial patrol. If they had been, this specific outage should not have occurred. While helicopter patrols are both necessary and efficient in most cases, they have inherent problems when it comes to identifying potential vegetation clearance issues because such patrols cannot consistently and accurately determine the distance between vegetation and conductors from the air. In cases where there is any question regarding clearances observed from the air, we recommend a follow-up ground patrol." [Source: NERC Transmission System Vegetation Management Standard Drafting Team, 8/25-26, 2004, p. 19.]

While not recent, the events described in the NERC documents reveal an ongoing challenge: No matter how well trained the crews, the potential for human error remains. In both cases, an additional layer of technology could have reduced those errors and possibly even have prevented those situations.

Now fast forward 7-10 years to 2011. Technology that was previously available only to the military is now commercially available.   

 

ASSIST-U.S.® Cessna 182 with Sensor

New light weight and powerful imagery data systems can be mounted on airborne platforms such as helicopters and fixed wing aircraft.      

This new imagery technology permits the collection and distribution in real time of aerial full motion video* during surveys that can provide a baseline of normal activity, while dynamically detecting areas of foliage encroachment and potential erosion. Integrated infrared cameras can be employed to detect unexplained heat sources such as failing transformers, which can be clearly identified during aerial surveys.    

Power Line Aerial Video Survey

After completing a survey, these sensors can also provide the full raw video files so maintenance and risk mitigation teams can identify problem areas requiring attention.   

Such recorded imagery establishes a record of historical data for future reference and greatly enhances post-event analysis.  

ASSIST-U.S.® can measure the clearance remotely and embed the measurement in imagery collected on full motion video.  We can take measurements between vegetation and electrical wires from our Cessna flying at low altitude, zoom in on and embed the clearance distance with our 26x zoom gimballed camera system, along with the Lat/Lon location, for immediate action by ground crews. For monitoring vegetation encroachment, the Cessna is faster and more cost effective than a helicopter.   

Power Line Aerial Video Survey

 

Captured digital video imagery can also be sent as single-frame pictures emailed directly from the aircraft to any address the user provides.  

   

These still frame captures can be sent as a single JPG image or provided in KML format for viewing in Google Earth, with all the geo-positional data required to correctly identify the exact area of concern.

 

 

 

 

 

 

  

* Full-motion video is video transmission that changes the image 30 frames per second (30 fps). Motion pictures are run at 24 fps, which is the minimum frequency required to eliminate the perception of moving frames and make the images appear visually fluid to the eye.

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