With world leaders gearing up to achieve net zero emissions by 2050, all eyes are on alternative offshore energy forms and more efficient and environmentally friendly means of procuring them.
Offshore wind farms provide one renewable energy source, with generation capacity predicted to soar from 35GW to 234GW over the next 10 years, according to the Global Wind Energy Council.
Wind farms are proving particularly popular in governments’ energy strategies, given the falling costs of provision and the fact that turbines can be placed ever further out to sea.
The main challenge with this energy source, however, is maintenance.
Typically, offshore windfarm inspection involves dispatching large vessels which carry tethered, underwater robots (Remotely Operated Vehicles) which are used throughout the year to monitor turbines, the integrity of cables and other structures that connect to the seabed.
These ROVs – controlled above water – enable access to areas that divers can’t safely or easily reach, and they come equipped with cameras, sensors, and robotic arms.
This set-up, which is also used by the oil and gas industries to monitor key marine assets and conduct seabed surveys, is managed from a ship or other floating vessel, and might be staffed by more than fifty people.
Such ships can be major polluters however, emitting an estimated 275,000 tonnes of carbon over their lifetime.
“Although the technology has evolved, the concept of capture on inspection work has remained the same since the 1970s,” explains Mike Gallo, technology business development manager at marine technology business Vaarst.
He adds: “It has involved large vessels crewed by people gathering vast amounts of data and spending time interpreting that data to get the insight required by the asset owners.”
According to Gallo, the industry is now undergoing a step change – moving towards operations that use less people offshore by leveraging artificial Intelligence, 3D Vision and autonomous robotics.
Undersea autonomy
The first step towards digital transformation in this sector are advances in the subsea devices themselves – with firms working on new ROVs with enhanced autonomy and features that allow for a wider range of tasks.
Trade title Offshore for instance, reports on the Eelume robot which has been developed by the Norwegian University of Science and Technology in collaboration with Kongsberg Marine and Equinor.
While still tethered, the Eelume connects to a docking station on the seabed and has been designed to live permanently underwater and perform subsea inspection, repair and maintenance tasks.
Live 3D modelling
Another disrupter in the world of hydrographic survey services is the capture technology that ROVs are furnished with.
Hydrographic survey company Rovco, for example, aims to replace the traditional video survey with computer vision and AI to create live 3D reconstructions of structures or of the seabed itself.
Rovco claims that these datasets open greater possibilities for marine engineers and those involved in the maintenance of offshore structures.
The way that subsea datasets are collected and processed is also changing.
Last March Rovco launched Vaarst to commercialise its intelligent data collection system ‘SubSlamx2’ – which combines a pair of 4K image sensors to deliver live scaled imagery and 3D models that can work at a low bandwidth without the need for a positioning system.
In an online product demo earlier this week Gallo said that Vaarst’s software provided ‘a lightweight, accurate dataset which is quantifiable and much faster to review’.
The Bristol based start-up has also just been awarded Bureau Veritas certification, verifying SubSlam’s sub-millimetre accuracy for live subsea measurement, which, claims the firm, makes it the most accurate real-time underwater measuring system in use.
Vaarst founder and chief executive Brian Allen added that verification that it is able to achieve sub-millimetre accuracy and maintain high levels of accuracy at distance, means that the firm is beginning to see more applications and use cases.
“With businesses able to conduct highly accurate subsea survey work with SubSlam-equipped ROVs, without ever having to place human divers in harm’s way, we’re making it easier, faster, cheaper, safer, and far more sustainable to manage and maintain energy infrastructure and realise a net zero economy,” he says.
During same presentation Vaarst’s head of professional services and support Joe Tidball showcased some of these use cases, including a mooring chain inspection for an oil and gas client as well as a cable inspection on an offshore wind farm.
The first client required highly accurate measurements in spots that were too hard for divers to reach. A Falcon SeaEye ROV- powered by SubSlam – was placed on a floating facility with live 3D reconstructions collected offshore to ensure adequate coverage of the mooring chain for high accuracy post-processing and detailed analysis.
The second use case involved subsea 3D modelling of an offshore wind farm in which SubSlam was put through its paces in a low visibility environment, for close range feature detection work on the cable protection systems.
According to Tidball, Vaarst’s technology is also capable of achieving ‘multi-session slams’ – enabling users to build large models over several separate sessions, allowing them to “pick up where they left off”.
In the near future Gallo adds that firms will have the ability to have multiple SubSlam-equipped ROVs working collaboratively as an autonomous fleet.
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