It takes seven minutes for cem baydar to get into the elevator of the ERH 5 wind turbine driving all the way to the top in lonnerstadt. 140 meters into the air. From there, baydar and his colleagues reach the inside of the rotor blades. The rotor blade must be horizontal in the air so that the workers can walk into it. At the widest point – the blades are slightly tapered – the blade has a diameter of 2.40 meters. Two workers fit in the elevator, one keeps an eye on the ground. They are connected to each other via radios.
If the elevator fails, the workers climb up a ladder inside the wind turbine. For this, they secure themselves on the ladder rungs, and protective suits, helmets and safety shoes are mandatory anyway. Climbing takes a lot of strength and concentration. It takes up to 20 minutes for a worker to reach the top, depending on how fit he is. In between, there are always platforms where he can take a short rest.
For cem baydar and his colleagues serhiy kunst and dirk sperling, it’s a daily routine. They have been working onshore (wind farms on the ground) and offshore (wind farms in the sea) for many years. "If you are afraid, you can’t work", says dirk sperling, his colleagues nod. Every year they have to pass new training and health tests for the job.
When the rotor blades are being repaired, the workers drive up the wind turbine on a platform. On a computer inside the wind turbine, all the data is recorded precisely, including the wind strength. If the wind blows more than ten meters per second, no one is allowed to drive up, and the same applies to rain.
Repairing minor damage
Cem baydar and his colleagues came to lonnerstadt because repair work was needed there. Reinhard kirchner from the operating company wust – wind& sonne explains that the wind turbines are externally inspected every few years. The wind turbine manufacturer, nordex in lonnerstadt, hires a service provider for rotor blade work.
"These are small damages, which must be removed regularly", says kirchner. Lightning has struck a rotor blade, so the top layer has to be resealed. For just under two weeks, the workers in lonnerstadt have been. They work with interruptions, depending on the weather conditions. Because the next few days are expected to be windy, they will take a break starting today and continue working when the weather is good. In the time the windmill can then also turn again.
Because while the workers are on site, the wheel stands still, even at night – a loss for the operating company. "There is already some loss of income", says kirchner. How much power – and therefore money – will be lost, he could not say yet. The repair costs and part of the downtime are covered by a full maintenance contract. In the event of lightning damage, the insurance company will cover it.