A life dedicated to the sound of wind
Brande / 20 October 2020
The invisible song of the wind is one of the hardest things to capture and tame – but not for Ejler Kristensen, who dedicated 38 years to the sound of wind. He has been part of the Siemens Gamesa family since September 1982 when he started working as an engineer in Brande, Denmark. From 1992 onwards, his focus has been on noise and vibration.
Let’s hop on a shiny, imaginary time-travel machine and push the “1982” button to suddenly find ourselves in the early dawn of Danish wind power. Ejler Kristensen just got hired as the first engineer in Danregn Vindkraft, a company founded in 1979 as the forerunner of Bonus Energy and Siemens Wind Power, which played a role in the historic development of Siemens Gamesa over the years.
Ejler’s work was hands-on from the very beginning: he remembers driving to Risoe Nuclear test station in Denmark on his first working day, where a department that tested wind turbines had been established a few years earlier. This is where he learnt his first lesson – that collaborating with industry experts is the key to success. “I had to work on wind turbine upgrades together with the engineers at Risoe. From the very beginning of my career, I knew that collaboration is the driving force in the wind power industry,” he recalls.
Ejler’s work was hands-on from the very beginning: he remembers driving to Risoe Nuclear test station in Denmark on his first working day, where a department that tested wind turbines had been established a few years earlier. This is where he learnt his first lesson – that collaborating with industry experts is the key to success. “I had to work on wind turbine upgrades together with the engineers at Risoe. From the very beginning of my career, I knew that collaboration is the driving force in the wind power industry,” he recalls.
Shaping the industry as we know it
Over the years, the job also required the ability to adapt to change and envision innovative solutions to complex problems. Turbine size was gradually increasing, and even though back in the day 95 kW turbines sold well in Denmark, there were some sound claims from neighboring residents. That was a turning point for Ejler. He started looking into novel ways to make next generation of turbines “quieter” to satisfy the needs of the growing wind power market.
He was among the first engineers to come up with practical solutions to minimize noise from wind turbines by using modern equipment such as microphones, accelerometers and analyzers to measure sound levels. Following his wishes, turbines with noise-related issues received upgrades such as a sandbox around the gearbox, a steel cover for the nacelle and cool air passing through silencers.
Sounds like another day for a barbecue
Solving new challenges has sometimes required fine-tuning personal plans to get the job done. “I remember one nice August morning in 2004, I received a phone call from work, telling me I had a plane ticket booked for me the same day to go and solve a noise issue with a 2.3 MW wind turbine in Scotland,” shares Ejler. “My wife took care of the barbecue and guests we had invited that evening, while I worked to solve the problem by installing tuned absorbers on the turbine’s bedplate,” he recalls.
Until quite recently, Ejler continued working with noise measurements, looking into the sound pressure and calculating the sound power level of prototype turbines or customer- owned turbines in case of noise claims. He reflects that there has been a positive development in the field over the years - even though turbines are getting bigger, they are no longer proportionally noisy, thanks to new aerodynamics technologies such as dinotails. Another exciting thing for him is mentoring colleagues on the job and sharing his proven-over-the-years expertise with the team.
“Personally, the most important lesson I have learnt is to research things thoroughly before making decisions about anything. It’s important to read things through and collect knowledge with an analyzing attitude,” he shares.
Ejler is now enjoying his retirement in Denmark with his family, taking to some of his favorite pastimes such as fishing, hunting and making homemade brews. As a farewell for the next generation, Ejler stresses the importance of enjoying your work in good cooperation with colleagues, and once the workday is finished, immersing yourself in nature.
Ejler is now enjoying his retirement in Denmark with his family, taking to some of his favorite pastimes such as fishing, hunting and making homemade brews. As a farewell for the next generation, Ejler stresses the importance of enjoying your work in good cooperation with colleagues, and once the workday is finished, immersing yourself in nature.
