Smart Grid: Drones for Utilities

Drones are one of the hottest technologies right now. They were a leading gift choice this past holiday season for kids and adults alike, so the topic is widely covered in the media and in discussions within the hobbyist communities. We all know that drones were largely developed for military use and they seem to be ideal for that application.

But what else can drones do besides being the in-demand consumer toy or the military lethal weapon?

Can they be used in the Utility industry and provide service for a variety of applications that would benefit from cost reductions and enhanced situational awareness?

Drones have many popular associated names depending upon the industry, country, and the application; these names include:

• UAV (Unmanned Aerial Vehicle)
• UAV (Unpiloted Aerial Vehicle)
• RPA (Remotely Piloted Aircraft)
• UAS (Unmanned Aerial System)

However they are referred, they have advanced technologically in a dramatically positive manner during the past few years. It has never been easier to fly nor more cost effective to operate a drone.

Figure 1 - Wind turbine inspection by a drone

Advancements in drone technology has included FPV (First Person Video) whereby the images seen by the airborne camera are relayed back to the operator for added control and more precise acquisition of imagery. Advanced drones include GPS and compass capabilities to aid in the ease of controlled flight and for station-keeping while in flight. Newer systems offer a dual control solution that permits the pilot to fly the drone while a second person controls the camera for recording. Advances in batteries has extended the endurance of flight times and permitted more gathering of video and data while airborne. Not all drones are battery operated, some use combustible fuel for longer endurance and speed.

Figure 2 - Magnetic field detection by a drone

There is a lot of confusion regarding drones. They are classified as consumer or commercial grades and the performance, functionality and costs vary by the definition. The entry level is for radio controlled toys. These can range from less than $25 to $1,000. This lower end drone is not considered in this article. Advanced hobbyists and Utilities can buy very capable drones in the $1,000 to $3,000 range that can be used for most Utility applications. This high end consumer drone is primarily used for photography and as an aerial video capture platform. The resolution is typically in the 6-12 megapixel range and provides quality still images and high definition television. The quality of the image is acceptable for most Utility visualization needs. At the next level up, we see low to medium end commercial units that range in price from $3,000 to $10,000. They are used for a variety of applications that may demand HDTV or 4k UHDTV video acquisition and a stabilized gimbal mount that delivers optimum pictures for integration into film production or for engineering review and planning. In the medium range from $10,000 to $100,000 we see drones with specialized cameras and an array of sensors attached that go beyond basic image capture duties. These drones are planned for agricultural analysis, land survey documentation, oil, gas and mining exploration and investigation, first responder work for aerial recording of traffic accidents, search and rescue, crime scene surveillance, fire-fighting analysis, and for gas and water pipeline inspection. Drones over $100,000 are used for the military and some new applications such as for border protection requirements, medical emergency support with airborne defibrillators, consumer package delivery, and more. Normally these drones are not operated with line of sight operations.

The real estate industry has been an early adopter employing drones for both interior and exterior video recording for sales presentations using high end consumer and low end commercial UAVs. Many experienced pilots can be found with real estate video production backgrounds.

Figure 3 - DJI S1000 with still camera

Utilities are considering drones that are operated with either LOS (Line of Sight) or the next generation of autonomous drones. Most drones today need an operator to control them while in flight and the operator must be able to actually see the drone with LOS for it to function properly. However, drones are being developed that can operate autonomously and fly a prescribed flight plan with key way-points tagged for precision navigation. If a drone is to be used to fly the right of way of a transmission corridor, then it will not be able to operate with LOS due to the distances travelled and physical obstructions preventing visibility to the drone. So, the operator may just launch it and then recover it at the predetermined and programmed destination point.

Even if drones use LOS or autonomous operation, they can begin to learn repeatable routes which can be tweaked for improved alignment resulting in better visibility of the transmission lines. These flight paths can be optimized for the best results considering the terrain, morphology, and the transmission infrastructure itself. Routes can be saved with way-points for future repeated flights of the right of way. Sensors can be added to further enhance even closer proximity flights to the targets so detection of the lines and the towers can be sensed in real-time and the drone can self-adjust its route so as to avoid collisions. These new routes can be saved for repeated flights. If reflectors or beacons are added to the transmission corridor, then drones can use these devices to report location and optimize the flight path. A PLC (power line carrier) or low cost WiMAX mesh that runs hundreds of kilometres down the right of way can help provide additional data to the drone and collect telemetry from the drone. These beacons can guide the drone’s flight path with constant communications. Drone flight telemetry would be relayed back to the network operation centre and the drone operators via this relay network further enhancing autonomous flight and recovery of the drone.

Figure 4 - Fixed Wing Drone, hand launched

Drones come in both fixed wing and multi-rotor, which is to say as airplanes or helicopters. A Utility would likely need both types in its inventory for different applications. Fixed wing can have extended endurance of flight to cover 10s of kilometres while multi-rotor platforms can hover in position for video logging of tower assets that can not be seen from the ground. This would avoid riggers or line staff climbing the structures which save time, money and promotes safety. Drones are ideal for the communication tower inspections as well as the transmission grid analysis.

The motivation to consider drones is driven both by the advances in available technology and core business justifications. Drones have better OpEX and CapEX metrics compared to alternatives like manned airplane and helicopter operations. This is not to say that drones will replace manned aircraft at Utilities, but they certainly can be used to augment them for initial inspections and analysis work of physical assets.

So, how will Utilities make the best use of drones? The China Merchant New Energy Group uses drones to inspect their solar farms for damaged panels in dense arrays. This video provides a good demonstration of their use at New Energy.

Drones can be ideal for assessing storm damage to transmission and distribution assets in a rapid manner or when access is limited or restricted due to road closures, deep snow, and washed out bridges. Drones can quickly locate downed power lines and help restoration crews optimize recovery work.

Figure 5 - Thermal photo captured by a drone

Drone operational endurance is the limiting factor for multi-rotors as battery life is limited by payload and time. Getting 15 to 20 minutes for endurance is typical for battery powered drones. The payload can consist of visual cameras for video recording and infra-red cameras for thermal imagining of transmission lines. Cameras can look at vegetation growth along the right of way in order can collect:

• visual records – still pictures and video
• multi-spectral imagery – plant health, water quality, vegetation index calculation, and plant counting
• thermal imagery – heat signature detection, animal detection, surveillance and security, water temperature and water source detection, and emergency response
• LiDAR – laser rangefinder, data collection for 3D modelling, and penetration of the plant canopy for height measurements
• hyper-spectral imagery – an enhanced version of the multi-spectral sensors, these next generation units can assess plant health, water quality, vegetation index calculation, plant counting, as well as full spectral sensing often used for mineral and soils / surface composition surveys

In order to mount these cameras and sensors, a stabilized camera platform is required that uses a three axis stabilized gimbal to control and aim the camera / sensor as well as maintain a smooth video recording by reducing or eliminating the inherent instability of the drone while in flight. Winds aloft, as well as thermal ducting and atmospheric stratification can adversely affect the drone while in flight and a quality gimbal will dramatically enhance the visual recordings.

In addition, there are sensor arrays available that measure airborne chemicals, pathogens, radioactive materials should such measurements be required. The availability of sensors is expanding and counts in the 100s already with more being developed. One operator is planning to use the Raspberry Pi computer in conjunction with the drone to derive data and combine functions that are not currently available, so the do-it-yourself community is active with drone developments too.

Figure 6 - Drone FPV with telemetry read-outs

Any discussion regarding drones would be incomplete if legislation and the laws governing their operation were not reviewed. These laws are complex topics and are still evolving. So, this is by no means a comprehensive review, just a commentary towards recommending a cautious approach. Airspace is a shared resource and is a highly complex issue. Clear and appropriate regulations are necessary and they take time to achieve. Of course, Utilities are required to operate any drones within the law. The development of drone legislation is at different stages of maturity in different countries. In most cases, these emerging laws have not yet been tested in the courts so it is expected that they will continue to develop and change over the next few years even after the initial laws are passed. Seeking proper legal advice is strongly recommended. With this concern tabled, Utilities should not shy away from drones as they provide a strong business case and the legal landscape will get better over time.

Figure 7 - Transport Canada drone infographic

Transport Canada has issued legislation governing drone operation and Canada is considered an early adopter country. They have divide drones into three weight categories (less than 2 kg, 2.1 to 25 kg, more than 25.1 kg) and have offered exemptions and guidance on legal drone operation. While this is all good and progressive, the limitations for operation are significant and may challenge use of drones in every location and for every application due to the strict restrictions listed. Here is a link to the Transport Canada drone page.

In the USA, the Federal Aviation Administration (FAA) is still developing its final drone legislation. In the 2012 FAA reauthorization legislation, Congress told the FAA to come up with a plan for “safe integration” of UAS by September 30, 2015. Safe integration will be incremental. The agency is still developing regulations, policies, and standards that will cover a wide variety of UAS users, and expects to publish a proposed rule for small UAS – under about 55 pounds – later this year. That proposed rule will likely include provisions for commercial operations. Anyone who wants to fly an aircraft – manned or unmanned – in U.S. airspace needs some level of FAA approval. Here is a link to the Federal Aviation Administration for more information regarding the operation of drones, but stay tuned as new legislation is expected early in 2015.

In June 2014, the United Kingdom’s Civil Aviation Authority (CAA) issued its third edition of the Air Navigation: The Order and the Regulations. This 480 page document covers all aspects of flight in the UK. It includes regulations for safe and legal drone operations. The aircraft must be kept within the visual line of sight (normally taken to be within 500 m horizontally and 400 ft vertically) of its remote pilot. Operations beyond these distances must be approved by the CAA (the basic premise being for the operator to prove that he/she can do this safely). Small unmanned aircraft (irrespective of their mass) that are being used for surveillance purposes are subject to tighter restrictions with regard to the minimum distances that you can fly near people or properties that are not under your control. If you wish to fly within these minima, permission is required from the CAA before operations are commenced. CAA permission is also required for all flights that are being conducted for aerial work (i.e. in very simple terms, you are getting paid for doing it). So, Utilities in the UK will need to seek prior permission for drone flights. The CAA Air Navigation: The Order and the Regulations can be found here.

Figure 8 - Beyond Visual Line of Sight or BVLOS drone departing for a long range inspection flight in Spain

Beyond Visual Line of Sight or BVLOS is the next area of drones to be tested and evaluated by the various regulators. Canada, United States, Spain and Australia are a few of the countries planning to evaluate BVLOS drones in 2015. BVLOS or autonomous drones are generally not acceptable in most countries today, but this is exactly the sort of drone that Utilities will want to operate in the future. So, until the legislation catches up with the demand, flying LOS drones, regardless if fixed wing or multi-rotors, should be the focus of Utilities today. To begin, use the high end consumer or low end commercial models for learning and to control the initial start up costs until you understand exactly what value these UAVs can bring to your company.

Drones are a rapidly maturing technology with lagging laws so it is smart to take a crawl, walk, run, approach. Besides, flying a drone next to high tension wires is inherently risky too, so developing familiarity and pilot skills is critical to your long-term success. Remember, safety first!

Michael Martin is a licenced fixed wing pilot for manned aircraft in Canada and he also flies his own drones with 3-axis gimbal mounts, GoPRO 3+ cameras, first person video downlinks, and with full flight telemetry remotely displayed. He uses these drones primarily as still image and video recording platforms. He flies them just for fun.

Martin has more than 35 years of experience in broadband networks, optical fibre, wireless and digital communications technologies. He is a Senior Executive Consultant with IBM's Global Center of Excellence for Energy and Utilities. He was previously a founding partner and President of MICAN Communications and earlier was President of Comlink Systems Limited and Ensat Broadcast Services, Inc., both divisions of Cygnal Technologies Corporation. He holds three Masters level degrees, in business (MBA), communication (MA), and education (MEd). As well, he has diplomas and certifications in business, computer programming, internetworking, project management, media, photography, and communication technology.

All images were sourced from the internet with the commercial rights belonging to their originators.