A lightweight robot capable of carrying out an X-ray maintenance survey of wind turbines – offshore and onshore – is being developed for the renewable energy sector. Forth Engineering, in Cumbria, is developing the RADBLAD technology which will complete a full X-ray survey of a Vesta 47 size turbine and all its blades in just five hours. Forth’s innovation is in line with the UK government’s policy of increasing renewable power to bring all greenhouse gas emissions to net zero by 2050.
This has led to a significant growth in installed wind power capacity within the last decade, especially in offshore wind power in the UK which is the world’s sixth largest producer of wind power. This growth has also meant a higher level of maintenance required across the industry with more wind turbines and more blades needing checking for faults.
At the moment such surveys are carried out manually by maintenance engineers climbing the wind turbine and its blades with rope access. Lives are being put at risk, with accidents and, in worst cases, fatalities. Turbine blades are subjected to gusting wind loads, driving the accumulation of fatigue damage in the blade structures, leading to failures. There’s also a high financial cost to such inspections. Preventative inspection every three to four months and maintenance every six months is necessary, costing between £70,000 and £700,000 each, depending on the location and the size of the turbines. To provide a solution, Forth is more than half way through a two-year project, funded by Innovate UK, to develop its RADBLAD technology.
The pioneering lightweight portable robot – each section of the RADBLAD system weighs less than 25kg – will make surveys safer, faster, and cheaper, removing the need to put lives at risk. The differentiation elements of RADBLAD, when compared with other systems, is in the use of radiographic based in-situ inspection, the automatic detection of defects using an artificial intelligent (AI) based software, and the use of a modular approach for the robotic system. The advantages of this system are early detection of blade (internal) defects, in a quicker, safer and systematic way, while reducing the risk to human operators. The manufacture of the technology is on course to be completed by the middle of July.
It has already been attracting interest from robotics and AI experts around the world and is set to be ready for testing on onshore wind turbines in September at Catapult Offshore Renewable Energy’s testing centre at Blyth in Northumberland ready to deliver the solution in time for March 2021. Peter Routledge, Forth’s programme manager, said: “RADBLAD is a world-first magnetically-adhering, wall-climbing robot, with a manipulator arm which deploys an x-ray system around a blade.
“An end effector holds the source and detector against the blade, so they move with the blade in the presence of 3-D blade vibrations. “A crucial and novel extension of RADBLAD lies in the use of a radiographic system for inspection and in providing an integrated solution that offers high-quality, efficient inspection method, which is human-safe. “Unlike radiography, RADBLAD does not require costly, time-consuming onshore dismantling of blades and transportation to workshop, inspection in X-ray bays and return and reassembly, which can take around ten days days during which time revenue is lost due to generating downtime.”
The consortium involved in the project – Forth, Innvotek, TWI, Catapult, Renewable Advice and London South Bank University – has been able to press ahead with the work during lockdown. The businesses and organisations involved have a wide range of expertise in robotic development and manufacture, radiography development, and AI algorithm software development. Peter said: “This project represents a clear technological innovation for the UK offshore wind generation industry, and a major growth opportunity for the SME supply chain consortium.”
There are about 350,000 wind turbines in the world. China, USA, Germany, India, Spain, and the UK are the top six countries in the world in terms of wind capacity. In the UK there are 10,790 wind turbines, 8,600 onshore, and 2,190 offshore. Mark Telford, managing director of Forth, said: “This will be another world-first for Forth and another example of where an industry has a specific challenge and has asked us to come up with a solution. This is the way we like to work and if other industries are facing similar challenges we are always happy to talk to them.”
Forth has been active on a range of fronts during lockdown – continuing a range of world-first projects, developing new products in the fight against COVID-19, and supplying vital equipment to help hospitals, care homes and businesses. A disinfecting robot developed by Forth during lockdown has gone into production. Forth has already sold several of its disinfecting cannons to industries preparing their sites to welcome back workers as lockdown eases. Forth is building three new offices at its headquarters at Maryport, doubling the size of its retail space at its trade counter, making more use of its 68,000 square-feet base in Cleator Moor as an innovation hub, and recruiting six new members of staff – four mechanical/electrical engineers and two design engineers. Forth has also sourced 18,000 items of PPE to donate to West Cumberland Hospital, and local care homes after members of Unite, GMB, and Prospect unions at Sellafield raised £30,000 in a community fundraising campaign.