Sarah Alban, Esri Writer
New Mexico’s largest electricity provider, Public Service Company of New Mexico (PNM), serves more than 500,000 residential and business customers. Reliably transmitting electricity across the high desert requires careful management of vegetation in the right-of-way (ROW).
PNM used to send ground patrol and helicopter surveyors to assess ROW vegetation management needs. The surveyors used foot patrols, ATVs, pickup trucks, and aerial resources to complete thorough vegetation inspections and write prescriptions to remain in compliance with North American Electric Reliability Corporation (NERC) FAC 003 regulations.
Foresters Damon Salceies and David Stricker identified, measured, and wrote clearance prescriptions, which they would propose for work. The environmental group checks to ensure the environment for proposed work is acceptable, but sometimes the group would require more information, entailing another field trip to acquire the needed data.
In 2014, PNM developed and implemented a desktop patrolling solution—with the help of Esri partners Clearion Software, Behron & Associates, GeoCue Group, and McKim & Creed—for a safer, faster, and less costly approach to vegetation management.
From the Desktop
To remain in compliance with the NERC FAC 003 regulations, PNM implemented a plan in 2014 to undertake a comprehensive inspection of 1,200 miles of the company’s transmission lines and perform the necessary vegetation remediation.
As part of the plan, PNM contracted with McKim & Creed for lidar data collection. The Esri partner acquired high-resolution lidar data of the ROW, which was processed and classified using GeoCue and Terrasolid software.
PNM then pulled the lidar data into ArcGIS with the LP360 extension by QCoherent, a GeoCue company. LP360 visualizes lidar data in the GIS. The 3D approach enables the foresters to perform a safer, more thorough execution of their tasks in a fraction of the time. One screen runs ArcGIS and the LP360 extension, which provides vegetation areas of interest and a realistic and spatially accurate view of the 3D point cloud; the forester can use this to make reliable measurements. Meanwhile, a second screen runs the Clearion work order management software, which is also on top of the Esri platform.
The Clearion solution, which integrates with PNM’s enterprise ArcGIS environment (ArcGIS for Server and an Oracle database), addresses two regulatory needs: it lets PNM patrol and document its ROW, and it captures work tickets with detailed audit history to prove that PNM has performed all requisite vegetation management.
“We were able to—with really very little implementation and training relative to the task—get someone at PNM who had never used GIS, in a position to review an enormous amount of lidar data and complete the work in a timely manner,” Clearion senior vice president Chris Kelly said.
From flying lidar data in August 2014 to deploying two foresters on desktop patrolling by December, PNM eliminated its need for field patrol and now gets more accurate, faster, less costly data.
“We were able to quickly go through the systems, and clearance accuracy of measurements gave us a complete inventory of the ROW,” Salceies said.
Salceies and Stricker engage a 360-degree rotating perspective of the ROW for better-than-ground angling and measurement tools; 2D profiles help determine vegetation elevation and clearances from the conductors, enabling highly accurate prescriptions to be written.
“There’s a lot of savings just from the accuracy of the data now,” manager of PNM Vegetation Management Anne Beard said. “Before we had lidar data, we didn’t have a sense of accuracy with what we had out there.”
Salceies and Stricker write prescriptions that are detailed down to the equipment needed to resolve any issues found with the vegetation.
“We can look at the topography and determine if something will need to be hand cut or if we can use mechanical means to address spans,” Stricker said.
All prescriptions are routed through the environmental department to ensure that any work proposed will be in compliance with all federal, state, and local regulations.
“It allows us to quickly submit the work and get responses,” Salceies said.
The foresters can quickly obtain any extra required information, saving an estimated one truck roll per work order.
“We’re using the computer and technology to enable the forester,” said Esri partner Ron Behrendt, Behron & Associates. “Knowledge and experience of the forester [are] empowered to more quickly and accurately create these prescriptions.”
The Clearion software pushes these prescriptions to tree trimmers, sprayers, and mowers in the field through a tablet application. Crew leads access the tablet orders and can enter information, such as status updates and notes, from the field. When staff close out orders, the information is input back to the office—in real time.
“The program syncs to the database and gives managers both feedback and an audit trail of what work has been finished,” Salceies said.
100 Percent Compliant
Regulators are showing a high level of interest in PNM presentations regarding its ROW clearing project. In addition, the Vegetation Management group has been demonstrating LP360 to colleagues to show how this system can be used for other gains across the company.
“There’s a lot of interest now, once they have seen the results,” Beard said. “Now that we have access to all of this information, it’s turning out to be more beneficial than just the purpose it was derived for.”
PNM is exploring whether its environmental group can use LP360 for identifying large cultural sites in addition to a wide variety of applications among the GIS group.
“It falls into their purview and has tons of information within it they could possibly use,” Beard said.
PNM estimates its lidar data will be accurate for several years, and the company has already been realizing time savings with desktop fieldwork as well as savings from the acceleration of prescription writing and planning work.
“I believe we have a much higher degree of certainty of what is out there on our system,” Beard said. “And it’s allowed us to formulate and prioritize a plan to where we can be a hundred percent sure that we are compliant.”