by Luke Currin, Duke Energy
Late in the blistering afternoon of Aug., 14, 2003, three high-voltage transmission lines in Ohio slumped onto some trees in conjunction with a human error, instantly cutting power to 50 million people across the Northeast.
After the Northeast blackout-the worst in North American history-power companies spent millions to fly helicopters over their power lines to meet new grid reliability standards.
“This is when a significant push for lidar came in our industry,” said Lee Mazzocchi, head of Charlotte, North Carolina,-based Duke Energy’s grid solutions department.
To more thoroughly monitor rights of way, survey helicopters began carrying lidar, a light-reflecting imaging technology that creates 3-D models of a given environment.
“The results were impressive,” Mazzocchi said. “Lidar’s 3-D models tell us everything we need to know about loading on our lines and nearby encroachments.”
But a decade after the blackout, utilities still spend millions to fly helicopters thousands of miles over their power lines.
Mazzocchi told a packed conference room of employees, however, that the nation’s largest electric utility hopes to do that job differently one day.
The company, he said, is investigating how well drones could do the job.
Flying Robots Make Business Sense
Unmanned aerial vehicles (UAVs), or drones, are known widely for their military applications, but businesses are increasingly finding peaceful, commercial uses for them.
Filmmakers want them to shoot scenes from the air, farmers want them to survey land and logistics companies want them to buzz packages to consumers in under an hour, making next-day delivery look like a Stone Age concept.
Energy companies from oil and gas to renewables want them, too.
The hype is contagious, but business won’t be piloting drones until the Federal Aviation Administration (FAA) deems them safe. The FAA has barred businesses from using them while it finalizes rules that govern their safe operations in the National Airspace System.
The FAA planned to finalize those rules by 2015 but announced in February 2014 it will not meet that deadline. Many are frustrated by the delay, but the administration is deliberating the implications of unlocking U.S. skies to drone commerce.
Members of the energy sector, however, operate and maintain components of the nation’s critical infrastructure. Some say drones can make the nation’s infrastructure more reliable and secure, perhaps warranting an FAA exemption.
Supporters of integrating drones into energy operations and maintenance tout dramatic cost reductions, enhanced preventative maintenance and increased safety. But critics respond with concerns about privacy, public safety and proximity to commercial aircraft, among other things.
Despite the FAA’s closing the skies to commercial drones, businesses still knock on its door.
Using drones to fly power lines makes sense, but drones potentially could benefit energy companies in countless other ways.
How Drones Fit at Energy Companies
With so many critical assets like substations and pipelines to keep track of, a major challenge for energy companies is ensuring those assets are inspected and maintained safely, often and in cost-efficient ways.
Consider a 200-MW photovoltaic (PV) solar farm. The site’s operators want any and every damaged panel repaired or replaced as quickly as possible. High performance from the site depends on such maintenance.
Most of this maintenance today is conducted by visual inspection, and crews often don’t have the time to fully inspect a site that hosts hundreds of thousands of PV modules.
A San Francisco-based drone manufacturer called Skycatch offers an interesting solution.
Skycatch asserts its tiny, four-propeller quadcopter can pinpoint a single damaged solar panel amid thousands by using thermal imaging to detect anomalous heat signatures. The quadcopter would fly inspection routes and ferry information on thousands of modules back to operators for their review.
Solarcity, the largest solar provider in the U.S., has signed a deal with the company.
Drones don’t just offer energy companies asset maintenance advantages; they also take humans out of harm’s way in many cases. High-risk jobs like scanning a wind turbine blade for cracks 400 feet in the air could be done easily by a quadcopter.
In addition to operations and maintenance benefits, drones could speed power restoration efforts in the aftermath of devastating storms. In 2012, the Electric Power Research Institute (EPRI), after significant testing, determined drones could assess damage and help bucket trucks and line technicians prioritize power restoration.
Despite all of the potential benefits energy companies could reap from drones, the FAA has been conservative in granting permission to test drones.
Two energy companies, however, have received the administration’s approval.
FAA Approvals, BP and Sempra
On June 8, 2014, an arm-launched drone with a 9-foot wingspan made history as it whipped through the Arctic air over Prudhoe Bay, Alaska, the nation’s largest oil field.
The flight marked the first FAA-approved commercial drone operation over U.S. soil.
The administration issued British Petroleum a Certificate of Waiver or Authorization to survey its pipelines, roads and equipment around its Prudhoe Bay operations using a Puma AE drone manufactured by California-based AeroVironment, according to an FAA news release.
Transportation Secretary Anthony Foxx told the press, “These surveys on Alaska’s North Slope are another important step toward broader commercial use of unmanned aircraft. The technology is quickly changing, and the opportunities are growing.”
Not even a month later, the FAA made San Diego Gas & Electric (SDG&E) the first electric utility to receive the administration’s approval for testing.
In sparsely populated airspace in eastern San Diego, the California utility is determining how well quadcopters, which weigh around 1 pound, measure 16 inches in diameter and cost around $3,000 apiece, can monitor transmission assets, according to an SDG&E news release.
The company is flying its quadcopters in four test areas in eastern San Diego County, each about 2.5 miles long and half a mile wide containing no residences or businesses.
“The unmanned aircraft system provides us with another tool in our electric and gas operations tool chest,” said David Geier, SDG&E head of electric transmission and system engineering.
The utility eventually wants to use the unassuming minicopters to locate the causes of power outages faster and improve its response to emergency situations such as fires.
Duke Energy: Drones Have Place at Utilities
Duke Energy is in the early stages of investigating how drones might benefit the company, said David Mohler, the company’s vice president of emerging technology.
After speaking with EPRI, the company intensified its focus. Mohler’s team has since identified more than 50 use-case scenarios for unmanned aerial vehicles.
Today, the company is working to apply for FAA exemption to test drones at one of its power plants in Mooresville, North Carolina.
“Our initial foray is to get an exemption for our Marshall test site in North Carolina,” Mohler said.
The Marshall test site sits next to Duke Energy’s Marshall Steam Station, a 2,090-MW coal plant on Lake Norman. Mohler and his team want to use a drone to investigate power fluctuation at the solar installation at the test site, among other things.
But the beauty of the Marshall site is that it hosts a range of technologies and assets.
With a coal plant, transmission lines, distribution lines, a switchyard, a scrubbed smokestack and coal ash repositories, in addition to the solar farm and energy storage, Marshall makes an ideal site for testing a drone in multiple applications.
Drones, Mohler said, could bring Duke Energy and other utilities considerable O&M cost savings, more accuracy of data and better asset security.
“The industry secures most of its switchyards and substations today with fences and locks,” he said. “What if we tethered a drone to the corner of a fence and let it fly over to provide real-time visibility and to help secure such sites?”
While Mazzocchi and Mohler are preparing for the possibility that drones could be mapping transmission lines and securing substations in the future, they aren’t expecting flying robots to be a part of normal operations in the near term.
“There’s a lot of hype around drones right now, but the FAA has a number of issues and concerns to work out before they’re commercialized,” Mazzocchi said. “That said, as the FAA begins to grant approvals, I suspect electric utilities could be among the first in line.”
Luke Currin writes about company and industry issues as a member of Duke Energy’s corporate communications department in Charlotte, North Carolina.More POWERGRID International Issue Articles
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