The next stage in the revolution

Wind turbines have enormous potential. Indeed, both the quantity of electricity produced and the devices’ reliability have significant room for improvement. The ETH spin-off RTDT set about tackling this challenge and developed a hardware/software solution in the form of Aerosense. The company’s offices in Technopark Zurich are equipped with all kinds of electronics and are littered with soldering irons, adhesive tape waiting to be used, and PV films ready for application. Here, the company builds prototypes that will subsequently be attached to the rotor blades of wind turbines.

From monitoring to design and control

Numbering eight people in total, the team has developed a hardware/software solution that collects aerodynamic, acoustic and structural data from rotor blades. Although they originally intended their product, Aerosense, for use in predictive maintenance, it turned out to be much more valuable for designing wind turbines. With that in mind, RTDT Laboratories quickly adapted its business model. “We started out with software for structural monitoring,” says CEO Imad Abdallah. “But when the manufacturers realised that we could also measure aerodynamics, our focus changed decisively.”

Suddenly, it was no longer a question of monitoring the structure but rather of using the collected data to improve the design of rotor blades and generate more power. “We can now work hand in hand with manufacturers to develop something that will revolutionise wind turbines,” says Abdallah. He himself worked as a senior engineer at Vestas, one of the largest wind turbine manufacturers, for eight years and devoted his whole career to wind energy before joining ETH Zurich as a visiting researcher and later as a senior scientist at the Department of Civil, Environmental and Geomatic Engineering.

Rethinking wind turbines

Most wind turbines are actually overdesigned in terms of material use, in order to withstand the adverse conditions they are exposed to. If manufacturers gain insights into how they can optimise the design, control, structure and aerodynamics of their rotor blades, the quantity of materials can be reduced by five to ten percent, with an accompanying reduction in production costs. “The fact that we’ve changed our focus doesn’t mean we’ve given up on maintenance. Our technology can still do that – just as it did before. But there’s another area of use that’s more profitable for our potential customers,” says Abdallah.

A plaster for rotor blades

Aerosense can be imagined as an intelligent plaster that is stuck onto rotor blades. It measures aerodynamic and structural factors – that is, vibrational characteristics, acoustic emissions, strain and the rotor blade’s temperature. The module takes five minutes to install and transmits data wirelessly to the software in real time. “It works like an Apple Watch or a fitness tracker, providing information on the physical condition of the rotor blade at all times,” says Abdallah. The latest system is currently in use in Austria, where the aim between now and the end of 2025 is for it to prove that it can survive in a real-world environment for a service life of one year. At rotor speeds of 80 to 100 m/s, temperatures of -20 to 60 degrees Celsius and high ambient humidity, even the slightest defects can lead to damage. Tests of this kind are therefore vital to determine whether Aerosense will remain operational over a prolonged period of time.

Milestones in future development

The year 2026 will represent another milestone for RTDT. By then, the spin-off plans to have achieved “soft integration” with a well-known manufacturer. “That means that we’re aiming for Aerosense to have achieved a lifespan of three years by then and for the rotor blades to come from the factory with the devices already attached,” says Abdallah. Once this stage is reached, it will be easy to scale the hardware up and use it on hundreds of units. RTDT plans to take the decisive step and achieve full integration at the start of 2027. “Our hardware would then be an integral part of rotor blades rather than just an add-on,” explains Abdallah.