Undersea drone geared to help offshore boom

Remotely operated vehicles can autonomously inspect wind turbines’ foundations without the need for divers

• By Neil Pooran / AFP, EDINBURGH

In a wave tank at a robot laboratory in the Scottish capital, Edinburgh, engineers observe in silence as an underwater drone rises stealthily to the surface.

The team, which led the development of the remotely operated vehicle (ROV) at Heriot-Watt University, said the submersible machine is a game changer for offshore wind farms, obviating the need for divers.

The engineers said it would soon be ready to perform inspections and maintenance at wind farms, transforming the nature of the high-risk and costly endeavors just as the industry is set for huge expansion.

British Prime Minister Boris Johnson has promised to make the UK the “Saudi Arabia” of wind power, with plans to generate enough electricity from offshore to power every UK home by 2030.

While Johnson is on his way out of office, the industry is banking on the expansion plans, especially after Russia’s invasion of Ukraine sent the price of traditional carbon energy through the roof.

“We have to imagine that in 10, 15 years time there will be hundreds of wind farms, which means thousands of wind turbines all across the coast of the UK,” said Yvan Petillot, a robotics and autonomous systems professor at Heriot-Watt.

“You also have hydrogen technology being developed and all of this will need to be maintained, inspected and serviced,” he said. “What we are developing is remote technologies where people can inspect and maintain those assets from shore, without putting anyone in harm’s way.”

In May the ROV, which is equipped with sensors and advanced software, conducted what is believed to be the first ever autonomous offshore wind farm inspection.

The device was deployed at French energy firm Electricite de France SA’s (EDF) Blyth wind farm, off the coast of Northumberland, northeast England.

It recorded videos that allowed researchers to assess the exterior condition of turbine foundations and cables, while its software created a 3D reconstruction model of parts of the energy company’s underwater assets.

Petillot said the 3D model can pick up the accumulation of micro-organisms, plants and algae on the turbine foundations. If a problem is detected, the ROV system can be deployed with a robotic arm to conduct a repair.

“The system will first do an autonomous inspection of the seabed and the structure, and build the 3D model that someone from shore can look at and say: ‘There’s a problem here,’” Petillot said.

“Typically you would have corrosion on the system, you might have to turn a valve, you might have to connect a cable, you might have to change an anode and clean the surface if there is too much bio-fouling,” he added

Maxime Duchet, an offshore wind research engineer at EDF, said the images and modeling would greatly enhance the ability to conduct operations and maintenance activities on-site.

Further tests are needed to estimate the time required to inspect all of the turbine foundations and to demonstrate the full potential of marine robotic technology, he said.

“However, it is clear from these initial results that the technology can ensure safer and faster operations and a reduced carbon footprint,” he added.

Engineers, who use a joystick to pilot the vehicle, say the ROV can be left alone to perform its primary mapping task for most of the time. If it becomes stuck, or lingers too long in a particular area, a pilot can commandeer it.

Petillot said a long-term benefit could be allowing more people to join the team managing the ROV remotely, who might not have been willing or able to work offshore.

It is incredibly difficult to find a diver or a qualified pilot for such projects, he said.

In contrast, finding somebody to help control the system as though they were playing a video game should prove far easier, he added.