If a tree falls in the forest ...
Progress Energy implements automated vegetation management system
Published In: Intelligent Utility Magazine September/October 2010
IF A TREE FALLS IN A FOREST AND NO ONE HEARS IT, DOES IT make a sound? That riddle was posed by the 19th century philosopher George Berkeley to explore questions about observation and the knowledge of reality—two subjects close to the heart of vegetation managers.
If a tree falls on a transmission line, the utility operator will immediately experience the reality of complaints. Not just from industry partners through cascading events and angry customers, but possibly from the North American Electric Reliability Corporation (NERC). Those not complying with NERC right of way (ROW) vegetation standards can suffer the painful reality of fines up to $1 million per day, per violation. NERC FAC-0031 regulations were an outgrowth of one of the main causes of the 2003 Northeastern blackout, which affected 45 million people in the U.S. and Canada—overgrown trees.
Automation and human observation
These are a few of the reasons Progress Energy was among the first large investor-owned utilities to implement a full-scale, automated vegetation management system to protect its transmission infrastructure. Progress operates two major electric utilities in Florida and the Carolinas serving more than 3 million customers with a generation capacity of more than 22,000 megawatts.
In vegetation management, professional human observation is critical. But the reality is that observation is useless unless accurately documented with maps and data, readily available to right of way crews tasked with preventing tree-related disasters, doing maintenance or making emergency repairs.
Located in the deep Southeast, Progress faces severe environmental conditions—dense, fast-growth vegetation in a 10-month growing season and killer winds from tropical storms and hurricanes that knock down trees. “In Florida we have such a sandy soil base and a very high water table, so we are limited to what herbicides we can use on our right of way floors,” said Paul Hurysz, Progress’ utility transmission forester.
In early 2007, Progress’ IT and vegetation departments began investigating technology to replace its paper-based system. By year’s end, the utility chose its software partner. In December 2008, its new integrated vegetation management platform went live.
Data utilization increases
Progress can now combine vegetation history with data acquired from ground patrols, helicopter flyovers and call-ins—all aimed at improving transmission reliablity, ensuring NERC compliance and optimizing resources.
“We are fully implemented with the program, but as we use it in the field, we develop and discern different ways of wanting to collect and reproduce the information we are gathering. We are probably up to 80 percent in utilization and 20 percent in the development mode to make the program better,” Hurysz estimated.
Prior to automation, Progress conducted helicopter patrols of its transmission ROWs three times a year using a paper-based system. With automation, it’s doing two aerial inspections, one in the spring before the storm season and one in the fall after the storms. In between, the utility added an annual ground inspection of NERC lines.
“Ground patrols are three to four times more accurate than aerial. In the air we are moving at 50 to 60 mph. On the ground, you have the opportunity to document everything as you move along. It’s much slower but a lot more accurate,” Hurysz said.
Progress is experimenting with voice recognition in helicopters. While there are ambient noise issues to be resolved, Hurysz is optimistic: “It’s a real benefit because when we take our eyes off the right of way we may miss potential vegetation issues. Voice is input to the tablet computer. From there we can take observations and download them directly into our system, sort the data and get it out to the contractors in a much more efficient and effective manner.”
More boots on the ground
Getting down to the weed level with electronically supported inspections has many advantages over aerial besides accuracy. With the paper-based system, information was often lost or shuffled around. Hurysz explained: “One challenge we have as a large company is you have folks transitioning in and out of business units, so many times you lose local knowledge. If a line goes down at night, having a database that tells a lineman or arborist exactly how to access a structure saves a tremendous amount of time to evaluate a situation or make repairs. One of our goals is documenting and capturing access points to improve safety, the reliability of our operations and restoration time.”
Another benefit of more boots on the ground is better customer relations. With information at the arborists’ fingertips, they can run reports on private property access, encroachments, or when a customer asks to be contacted about a tree trimming or animal-related issues.
“We are more effective. We have not had any outages since we installed the system, so it’s had to measure exactly how much savings the system is generating, but it’s helping us maintain compliance, which is the total objective of the program,” Hurysz said.