Utilities have high hopes for drone use

As they look to cut operational costs, energy and water companies are turning to drones for inspection and monitoring. Stephen Cousins reports.

Drone use by utilities is on the increase and as the technology advances and prices come down a range of new applications are helping streamline operations, improve safety and cut costs.

Unmanned aerial vehicles (UAVs), fitted with sensors and high-resolution cameras are increasingly being deployed to support the monitoring and maintenance of assets like transmission lines, wind turbines, or other infrastructure where human intervention is impractical or dangerous.

Joanne Murray, UK drones assurance lead, PwC: says “The ultimate aim for UAVs is increased automation, so the technology can perform the required data capture with minimum input from a pilot. Many commercial drones are currently flown using a pre-programmed flight path but the human is still very much in the loop. Technology is advancing to the point where drones can fly as swarms or can be located in a box and fly daily routes independently of any pilot.”

Severn Trent Water, whose pioneering use of drones enabled £750,000 of savings in the first year of operation, is turning increasingly to thermal imaging to identify faults, leaks or other anomalies.

It used the technology to scan anaerobic digestion tanks to highlight changes in temperature that might indicate a leak or a loss of efficiency and to monitor the flow of wastewater from a sewage treatment works through reed beds.

Keith Leadbetter, operations and maintenance assurance manager at Severn Trent Water, says: “Thermography can tell us if reed beds are working efficiently or ‘short circuiting’, which can reduce their efficiency or cause reeds to die. It means we can step in and stop any risk of pollution. We also track the route of wastewater as it flows through settlement lagoons [wastewater has a slightly higher temperature than surrounding water] to ensure the process is efficient and if there’s a build-up of silt where the water is being forced around a different route.”

Confined or restrictive spaces are often no-go areas for humans, but the ELIOS 2 drone by Flyability has been specially adapted to buzz around them without the danger of busting its blades.

The machine is surrounded by a carbon-fibre protective frame designed to bounce off obstacles without interrupting the recording of high-resolution stills or video. Severn Trent Water used it to study culverts as well as the substructure of wells due to be capped, to help contractors understand the work required and the risks involved.

However, prospective users need to be aware of certain caveats, says Leadbetter: “It is not EX-rated so you can’t put it in an explosive atmosphere. The older version of the drone had a fully rotational cage that would spin if you hit something so the cage would appear in the video footage, but the latest model has a window in the cage to prevent that from happening.”

Drones can now be adapted to carry bespoke payloads and equipment, not just conventional cameras. LiDAR remote sensing is a potentially more effective method to pinpoint vegetation that needs to be cut back to prevent damage to infrastructure leading to fires or outages.

New York Power Authority plans to use the system to manage vegetation along its transmission lines and a similar use is being investigated by business and IT consulting firm CGI for a utility client.

Rich Hampshire, vice president of digital utilities at CGI, tells Flex: “Earth observation satellite imagery could identify potential areas of vegetation growth and that ‘crude’ picture can be used to target specific problem areas using other imaging techniques, such as LiDAR mounted on a drone to capture much higher resolution imagery.”

Modern UAVs can even be hardwired to “smell” the environment. Canadian company Scentroid sells a Sample Drone fitted with sensors and equipment designed to measure and sample chemicals like ammonia, sulphur dioxide, VOCs (volatile organic compounds) and other pollutants. The samples are brought down and analysed to help wastewater treatment plants keep tabs on levels of odour and air pollution.

Flying machines aren’t all about snazzy hardware; advances in software processing allow utilities to do much more intelligent things with captured footage.

Connected Drone, developed by Norway’s eSmart Systems, uses AI to automatically scan thousands of drone-captured images of assets, like towers or poles, for signs of damage or faults.

The software was used by a major transmission system operator in Denmark to detect rust, in a dataset of 7,500 pictures the issue was identified with 96 per cent accuracy. According to eSmart, the ability to track rust development over time has enabled the operator to more accurately forecast maintenance requirements. A utility in Norway that used the system to scan infrastructure was able to avoid as much as 25 per cent of outage-related costs caused by defects that previously went undetected.

The system needs human training to reach its full potential, says Phillip Yoxall at eSmart Systems: “Connected Drone automatically analyses all images and links them to the related asset. When unknown components and defects are not detected, a human expert annotates them. Annotations go into training AI algorithms for automatic detection: the more annotations made, the more automated and intelligent the software becomes.” Discussions with UK distribution network operators are ongoing with a view to carrying out pilots in the coming months.

The growth of edge computing, which transfers computation and data storage closer to the location where it is needed, in the process reducing network bandwidth requirements and latency, could ramp-up the capabilities of drones in future by giving them the ability to process and analyse data for themselves.

Combine that with advanced AI, we could see the advent of autonomous smart drones able to inspect and detect defects or malfunctions without human assistance.

Today’s drones are typically used for specific short-range tasks, but greater efficiencies could be achieved if they were allowed to fly over much longer distances that take them out of sight of a human operator.

Such “beyond visual line of sight” flights currently require permission from the Civil Aviation Authority and can only occur in specific, restricted cases. However, a three-year government-backed trial is under way, coordinated by the Energy Innovation Centre (EIC) and involving aviation specialists Callen-Lenz, the CAA, Wales and West Utilities, Cadent, National Grid Gas Transmission, Northern Powergrid, Northern Gas Networks, Scottish and Southern Electricity Networks and UK Power Networks, and supported by Connected Places Catapult. The project is aiming to develop a regularised framework for out-of-sight drone flights in the UK.

If implemented, it could lower costs and increase availability compared with traditional asset monitoring techniques. Tony Knowles, project support at the EIC tells Flex: “Wider cost studies covering a variety of remote inspection tasks and generic drone types suggest a cost saving of 50-75 per cent can be expected over a manned helicopter… Inspection drones will be easier to deploy, an advantage potentially more significant after storms or other ad hoc inspection tasks. Operating windows can be extended to include evenings or potentially night, a feature that could aid infra-red analysis.”

The first phase of the trial, completed at the end of 2019, evaluated different technologies and techniques for flight operations on gas and electricity network assets. These included tests of satellite, cellular and mesh communications, the integration of novel ground centring technologies, and risk management and operational parameters.

A report concluded that no significant operational issues were found that would present a problem and the next phase sees drones carry out specific energy industry-related tasks in ‘normal’ non-segregated airspace.

Out-of-sight droning signals an exciting new frontier in drone use.