IROTOR TECHNOLOGY: New blade sensor technology to limit strain and to lower cost

A strong partnership has resulted in the development of a new wind turbine technology, which could mean a leap forward in blade control and cost reduction.

Leading Danish wind industry players and the scientific community have joined forces to develop the iRotor technology, a solution which uses wireless sensor technology to measure changes in the geometry of wind turbine blades in operation. Measuring the geometry of the blade, the system allows for more efficient operation of the turbine and mitigates loads on the blades, addressing a key challenge particularly found onshore in the wind industry.

“With more turbines installed at low wind sites, the need for more precise blade control becomes more acute. The iRotor technology will allow for longer and lighter blades to be used, a key step towards lowering the cost of wind energy,” says René Balle, CTO at KK Wind Solutions, one of the partners in the project.

Longer blades at limited cost

Launched in June 2013, the iRotor project is scheduled to run for three and a half years. Partners in the project include three players from the wind industry: LM Wind Power, manufacturer of wind turbine blades, KK Wind Solutions, supplier of electrical solutions, and Polytech, who delivers the integrated lightning protection technology. Also part of the project group are world-leading experts in radio-based sensor technology from the University of Aalborg, Denmark.

“This project combines two of Denmark’s strongest areas of expertise – wind and radio sensor technology – to develop an innovative solution. In essence, the technology will extend what can be achieved using existing blade design, material and process technology, which we expect to have a strong commercial potential”, says Claus Byskov, Senior Manager, LM Wind Power.

Collaborating closely to share both knowledge and the cost of research between the parties has been key to the success of the project. The Danish state’s Innovation Fund Denmark, who invests in development projects that has a potential to create growth and employment, has contributed 33 million Danish kroner of the total research cost of 65 million (€8.7 million).

“The joint effort proves that by combining different fields of knowledge, we can break technological boundaries which would not be feasible financially or technologically for any of us as individual players”, says Mr Balle. Gaining new insight into blade control could lead to further technological advance for both on- and offshore wind.

To Aalborg University, too, the project has provided new opportunities. “Our ideas have been new and often unconventional to the wind industry, but the project partners have been very open and responsive to our input, which has resulted in a very positive collaboration. For us, the project has been both challenging and rewarding and I believe we have taken a big step forward in adapting  our technologies to match a technological demand in the market for wind”, says Professor Gert Fr0lund Pedersen, Institute for Electronic Systems, Aalborg University.

Full-scale tests ongoing

In July this year, the project reached a significant milestone when the first iRotor solution was installed on an Envision EN-120/3MW test turbine at the Danish Test Centre for Large Wind Turbines at Oesterild. KK Wind Solutions has installed the electrical components of the iRotor solution and the infrastructure, enabling the collection of data. The iRotor is now undergoing full-scale tests.

Results from a previous full-scale pilot project demonstrated that wind speed data derived from the radio based sensor aligned well with measurements from nacelle mounted anemometer, providing even better data and possibilities in relation to turbine control and load mitigation. The full-scale tests are expected to confirm these findings.

“We expect verified results before the end of this year. In parallel, LM Wind Power and KK Wind Solutions will start commercialising the solution. It is premature to say if and when the solutions will be ready for serial production, however we trust it will be before the end of the funding period, which runs until mid-2018”, says Mr Byskov. Although not yet ready to bring to the market, the technology has already attracted interest from some of the world’s largest wind turbine manufacturers.

With thanks to Peter Gisselmann Rasmussen, Communications Specialist at KK Wind Solutions A/S

Note: The article previously appeared in the October 2015 edition of the Offshore WIND Magazine.