Academics aim to ‘turn the tide’ on windfarm industry’s maintenance bill of millions.

Posted on 18th July 2018

Academics at the University of Chester are part of an international energy research project, which aims to save the windfarm industry millions in off shore maintenance costs and help enable the continued expansion of the renewable energy mix.

Offshore wind turbines image - Getty Images
Offshore wind turbines image - Getty Images

Dr Yu Shi and Dr Yu Jia, who are both Senior Lecturers in the Department of Mechanical Engineering at Thornton Science Park, are working with partners in the UK and China, to find a more innovative, and cost effective way to maintain off shore wind turbines. 

The international group consists of the University of Chester; and Southampton-based Ilika Technologies, in the UK. Ilika is a pioneer in material innovation and solid state battery technology. Dr Yu Shi has returned from a research visit to China, where he met the Chinese partners in this project – Titan Wind Energy (one of the largest manufacturer of wind turbine blades in China), and Nanjing University of Aeronautics and Astronautics (NUAA). The project has received Innovate UK funding of £500,000 (with a similar amount funded by Jiangsu Province in China).

The UK-Chinese partnership is working to give wind turbine blades their own built-in self-sustaining autonomous sensors. This means that, in potentially challenging off-shore weather conditions, the sensors will not only monitor the blades of the wind turbines, they will also be harvesting their own energy. It will then be easier to detect any internal or external problems with the blades, especially in terms of environmental, humidity and temperature issues.

According to government reports, the UK has some of the best offshore wind resource in Europe, with relatively shallow waters and high winds. Together, China and the UK contribute approximately 40% of the world's 500 GW wind power capacity. (500 GW (Gigawatts) is the world capacity in wind power at the moment. China is the world’s largest producer of wind power.) Offshore wind has been recognised as a key technology that will help the UK meet the 2020 RED (Renewable Energy Directive) target. According to a 2013 The Crown Estate report, the UK has the most ambitious programme for offshore wind installation in the world, and operation and maintenance (O&M) activity accounts for approximately one quarter of the life-time cost of an offshore wind farm. In the same report (A Guide to UK Offshore Wind Operations and Maintenance), the Crown Estate states that the market for offshore O&M services is expected to reach £1.2 billion a year by 2020 – in the UK alone.

Dr Yu Jia said: “Maintaining off-shore wind turbines currently comes with high labour costs. The current way to detect what happens inside the wind turbine blade (and therefore analyse the health of the equipment, and any potential problems) is labour intensive. Those who maintain the structures are either helicoptered out to them, or drones are used, to check and maintain the health of the turbines. The contribution of wind energy is pivotal in order to transition to clean energy and slow the effects of climate change. Given its priority as a renewable energy, finding ways to make wind turbine maintenance more efficient and cost effective is key – and that’s where we believe our research comes in.”

Dr Yu Shi said: “The ever-increasing operation and maintenance costs have become a critical constraint for the sustainability of wind energy growth. The primary objective of this project is to develop an integrated smart composite which will be incorporated onto the wind turbine blades. These ‘smart sensors’ will be powered by a combination of an energy vibration harvester and a solid state battery. The composite will be able to perform autonomous structural health monitoring of the blades, to detect the early signs of damage – this will help predict maintenance scheduling and prevent the icing of the blades. It means that the power supply will be sustained, without the need for battery replacement – also ensuring the blades’ operational efficiency.”

In the UK, the solid state battery (Stereax® M250) has been developed by Ilika. Solid state batteries use solid electrodes and electrolytes, rather than liquid or polymer electrolytes found in traditional lithium ion batteries. They have a high energy density, small size and flat form factor, are tolerant to higher temperatures and have a longer cycle life.

At the University of Chester, Dr Yu Jia and Dr Yu Shi’s expertise in this project lies in their extensive research knowledge of vibration energy harvesting and advanced composite materials. (Advanced composite materials are high performance, high strength fibres (resins) with unusually high stiffness. A major customer of such advanced composites is the aerospace industry.) Dr Jia and Dr Shi will be leading on the advanced composites element of the project, and the integration of Ilika’s battery and electronic components into the blade (into the tip). They will be undertaking vibration analysis to assess any damage to the blade. Computer modelling will also be undertaken at Thornton Science Park, to predict the damage formed within the composite material – and to simulate the detection process of any damages. Transducers (electronic devices which convert energy from one form to another) will also be used to harvest the vibration energy (the energy from the aero turbulence of the blades themselves as they go around), to achieve the blade’s ability to power itself.

Garfield Southall, Executive Dean of the Faculty of Science and Engineering at the University of Chester, said: “This is an extremely exciting project, which brings together international partners with their own areas of expertise in this field of renewable energy. This research will open up new technological possibilities in the design, manufacturing and operation of wind turbine blades. This will ultimately help to improve the operational efficiency, save maintenance costs, and increase the contribution of renewable wind energy towards the global energy demand – to conserve the environment and curb CO2 emissions.”

He added: “The outcomes of this research are also expected to benefit composite material research in the aerospace, marine and automotive industries. Smart sensors are not just limited to wind turbines. The low weight, long life aspect of these devices means they can be used in a variety of areas from aircraft to automotive.

“Another aspect of this project, which is very exciting, is that we will be able to align aspects of this research with short term undergraduate and postgraduate research projects at the University of Chester. This will help to develop specialist skills for our participating students and young researchers.”

The University of Chester is keen to hear from researchers who would like to be part of this exciting renewable energy project. For further information, please contact Dr Yu Jia: y.jia@chester.ac.uk; or Dr Yu Shi: y.shi@chester.ac.uk