The potential for wind power to almost single handedly get us to net zero is remarkable. Switching from coal-fired generation to wind power can reduce the carbon emitted from energy production by more than 99 per cent.[1]
However, wind turbines and other offshore renewable energy assets require maintenance and that process in itself generates carbon. Vessel operations, helicopter transfers, and equipment manufacturing are all polluting, accounting for about 10 per cent of total emissions from offshore wind.
The UK alone has more than 2,600 offshore wind turbines, delivering around 26GW of power. The UK government has adjusted its targets for offshore wind capacity by 2030 to a range of 43-50GW including 5GW of floating offshore wind, a reduction from the previously stated goal of 60GW due to supply chain constraints [2]. Meeting this target would require the addition of approximately 20GW of new capacity by the end of the decade, around 1,800 new turbines.
Maintenance check-ups
On average, each turbine requires up to three maintenance check-ups per year, a frequency that increases as turbines age.
That means, of course, the more wind turbines we build, the more carbon dioxide we produce in doing so and there exists a need to ensure we find ways to keep those emissions down.
Colleagues of mine will next month be detailing the work we’re doing on this at the annual All Energy conference in Glasgow which this year is appropriately titled, “Engineering a Net Zero Future”, and our work certainly represents an engineering challenge.
The unpredictable nature of the world’s oceans means robots will need certain capabilities to perform subsea inspections and repairs efficiently and in a safe manner. This is one of the challenges currently being addressed by the £1.4m EPSRC funded Underwater Intervention for Offshore Renewable Energies (UNITE) project which is developing subsea robots guided remotely from an autonomous vessel on the surface. For this, we have partnered with Imperial College London on visual inspection and Fugro, who are developing some of the most advanced unmanned marine robots in the world and the only 12m unmanned surface vehicle allowed to operate in UK waters.
But this requires us to first solve the so-called “chicken head problem” - keeping a robot's arm steady against a structure when it is being buffeted by currents and waves. This necessitates advanced control systems and machine learning algorithms to be developed to allow robots to adapt in real-time to changing conditions.
Perception system
That’s just one part of the problem, however. Another missing component is a perception system that can handle the limited visibility under the sea. Visual solutions do exist for online mapping and localisation, but these are only efficient at relatively short range and in good visibility conditions. Acoustic mapping can be used at long range and is not dependent on the condition of the water. However, acoustic sensing provides low resolution and low detailed data compared to optical sensors. There is currently no system that efficiently provides an integrated acoustic-optical mapping solution, and yet it is in high demand from the industry.
Sensing and navigation
So, the AWARE project is working on a sensing and navigation system fusing forward looking sonar data with a Simultaneous Localisation and Mapping (SLAM) system, to generate all-weather 3D maps. These will provide real time models of the environment that can be used to plan inspection and repair missions whilst always maintaining safety. Furthermore, it will be possible to retrofit these systems to existing Remotely Operated and Autonomous Underwater Vehicles (ROVs and AUVs) hence the system would be able to be used by a wide range of users, from researchers in robotics to robot manufacturers and survey companies. It could also be used in other sectors such as archaeology, environment monitoring, and fisheries. The system would enable smaller robots to perform these missions, which means smaller support ships, more flexible deployments, reduced operational costs and, of course, lower emissions. This project, sponsored by the Net-Zero Technology Centre in Aberdeen, is a collaboration with Frontier Robotics, a spin out from Heriot-Watt University specialising on autonomous inspection and Fugro Ltd.
Safety & Data
Using robots has one other distinct and important advantage in that it takes humans out of harsh and dangerous environments, with the robots sending data back to operators on shore.
For this, we need to consider the mechanics of human-robot interaction. In this new world, remote data collection, fusion and interpretation become central, together with the ability to generate transparent, safe actionable decisions from this data.
The vision of the EPSRC Funded Human-machine teaming for Maritime Environments (HUME) project, a collaboration with SeeByte Ltd, was to develop a coherent framework that enables humans and machines to work seamlessly as a team by establishing and maintaining a single shared view of the world. It addressed fundamental research questions in the field of machine-machine and human-machine collaboration, robot perception, explainable autonomy and AI.
Technology could transform offshore wind maintenance, potentially reducing fuel consumption of maintenance missions by up to 97 per cent - from 7,000 litres per day to just 200 litres.
That’s more than just a drop in the ocean.
Yvan Petillot, Professor of Robotics and co-academic lead at the National Robotarium
[1] Orsted report
[2] Essential reforms to pave the way for clean power by 2030
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