Significant investments throughout Asia Pacific (APAC) have considerably improved the region’s energy infrastructure during the last few decades. The electrification rate in developing Asia has surpassed 90 per cent. With the introduction of high capacity power grids, however, facility maintenance and operation has become quite challenging. Natural disasters, unstable renewable generation and rising energy security concerns are some of the challenges that power providers in the region are currently facing.
Meanwhile, with the introduction of new technologies, artificial based solutions for addressing such challenges become available. Drones and other unmanned aerial systems (UAS) are increasingly being utilised to automate the planning, construction, and maintenance of energy plants around the world. UAS and digital technologies are making energy sector operations faster, safer, and more cost-effective. The main issue for emerging Asia is to stay up to speed with the rapid pace of global technical innovation while also seizing the opportunities that are available.
The study by Asian Development Bank named “ The Value of Unmanned Aerial Systems for Power Utilities in Developing Asia” highlights the advantages of using UAS in power systems and highlights energy-related challenges that the technology can address. It also demonstrates how UAS has been used successfully in a number of countries as a cost-effective and safe instrument for inspection and data collection.
Climate change and an increasing number of extreme weather events pose both long-term and short term risks to energy infrastructures and can lead to power outages, increased maintenance, and capital costs. Coronavirus disease (COVID-19), a new form of risk, can have far-reaching impacts on power system design, markets, and operation, such as a large reduction in demand, substantial changes of load profile, and continuity of operations and maintenance. It has become a prolonged crisis that grid operators are now worried that if huge numbers of essential staff were contracted, key infrastructure could become inoperable. Uninterrupted electrical service is paramount as health sectors, food industries, supply chains, and other lifeline facilities count on a stable power supply to maintain functions. Operation and maintenance to achieve a reliable power supply without social contact and mutual aid became even more challenging.
Power system reliability and resilience depend on the quality of equipment, installation, construction, and more importantly, on the years of dedicated professional operation and maintenance (O&M). With the increasing demand for electricity, power facilities continue to expand. However, the O&M of those facilities still rely heavily on manpower. The work has become increasingly burdensome, dangerous, and challenging. Problems and shortcomings that have been observed are as follows:
- Workforce safety hazards: Power engineers often have to travel to remote areas and climb on high towers. Occupational risks include falling, electrical shock, animal bite, etc. Long time working in such environment would create tremendous psychological pressure.
- Low working efficiency: Manually climbing to inspect towers, insulators, and conductors is time-consuming. It often takes 3-4 hours to prepare and climb for a single tower inspection which would result in long delays of operation or recovery.
- Limitation at hard-to-reach locations. Private properties, difficult terrains, restricted areas, or natural hazard-affected areas are hard to approach or cross for engineers.
- Misjudgments, lack of complete documentation, and non traceable inspections: The inspection results mostly depend on the naked eyes and the personal experience of a lineman or engineer. Little imaging or data is recorded for future review.
There are other inspection solutions such as robots, which have been introduced for automation (Tavares 2007). Helicopters with engineers on board are also used in many countries (Schaller 1999). These solutions are more complex and costly, and many utilities cannot afford and easily adopt them.
The fast-evolving energy sector highlights the importance of adopting a broad and dynamic approach to energy security. With the development of communications and digital technology, Unmanned Aircraft System (UAS)—or commonly known as drones—applications have appeared in the energy sector in the past 5 years, providing utilities with a smart tool kit while streamlining the entire inspection process.
UAS solutions have been widely accepted by power utilities and renewable energy companies in many countries like Australia, Canada, the People’s Republic of China (PRC), Spain, the United Kingdom, and the United States particularly by power companies running tens of thousands of kilometers of transmission lines. The national grid in England and Wales has been using six drones for the past 2 years to help inspect its 7,200 miles of overhead lines (Vaughan 2018). Duke Energy of North Carolina in the US, is using drones to conduct infrared equipment inspections, survey storm damage, and inspect tall structures.
Drone-related startups are also emerging in some of the developing economies and the commercial use of drones is experiencing exponential growth in many sectors. In India, the drone has been seen applied in many civilian sectors for aerial photography; survey and mapping; reconnaissance and surveillance; and inspection of transmission towers. (Amazon 2014). Indonesia has been using drones since 2014 for various purposes, such as fire spot identification in forests, coastline delineation, and surveillance of oil palm plantations. Drones have also been utilized in towns of the Philippines to spray fertilizer on vegetable farms located on mountain slopes (Malasig 2018). Drones are also used in other sectors like telecoms, insurance, transport, and logistics.
As the capacity continues to grow, the broader will be the expansion of the industry application. Equipped with hundreds of drones, China Southern Power Grid Company inspected more than 500,000 km of transmission lines in 2019 (CSG 2019). With new tools, 60% of the inspection personnel were mobilized to support operations. This enhanced the overall maintenance capabilities, efficiency, and responsiveness of the team. The UAS application in the energy sector has been tested successfully in some countries. Yet, it is not widely recognized and applied in most ADB DMCs. Duplicating these UAS applications bring similar benefits including safety, efficiency, and reliability.
UAS applications in power utilities
An unmanned aircraft system (UAS) includes a drone, a ground-based controller, and a communications system between the two. There are many types of drones, which can be categorized into small, medium, and large in terms of weight; and fixed-wing, and rotary-wing drones in terms of wing type. The load capacities, speeds, and flying ranges are varied depending on the size and type. The selection of which type of drone to use will have to meet the requirements for a specific inspection. The performance is shown in Table 1.
Today, UAS are selected and deployed subject to inspection scenarios. The commonly used quadrotor or multirotor drones are capable of precise flying and hovering for detailed tower examination, while fixed-wing drones are often designed for long-range line route inspection. However, this is not always the case. A large size rotary drone is capable of both long-distance and detailed inspection.
Regarding the inspection requirements, UAS is equipped with different sensors and cameras to take visual, infrared, or ultraviolet images to detect various types of faults or defects. The visible light camera is the primary equipment to take clear and sharp images for components and parts of power lines. The inspection often requires higher resolution and better optical zoom functions.
Defects can be snapshotted such as broken wires, loose bolts, damaged insulators, pollution flashover or damper deformation, etc. The infrared camera mainly serves as the thermal detector for overheated fittings or parts due to its mechanical or mounting defects. It can also be used to monitor wildfires along line corridors. The ultraviolet camera is used for examining the discharge by detecting corona or arc happening on the conductors, insulators, or fittings. Light Detection and Ranging (LiDAR) is another essential equipment for inspection and survey. The equipment with laser light can measure distance, make high-resolution maps and build 3D models. LiDAR and drones are perfectly fitted for the survey and mapping of the long-distance transmission corridor.
The original report can be accessed here.