Wind farm blaze: boss blames 'negative power prices' for strain on old turbine

Ramping up and down of 25-years old wind farm may have caused fire, managing director tells Recharge

A turbine blaze in Germany was indirectly caused by ramping the ageing machine up and down due to negative electricity prices in the nation's power market, the managing director of the wind farm claimed.

No one was hurt in the blaze at the Stemwede Bürgerwindpark in Germany’s North-Rhine Westphalia state early Tuesday and the local fire brigade made sure the fire didn’t spread to nearby fields.

“The operator himself had already attempted to extinguish the fire in the area and shut down the system,” the Stemwede fire brigade said in a note.

“Since it was not possible to extinguish the system itself, the emergency services secured the site and regularly checked the area for embers.”

Wilfried Winkelmann, managing director of the 6MW wind farm, told Recharge: “A defective brake started the fire. That was the cause. We had to brake several times because of the negative electricity prices. This is required by law,” Winkelmann said.

“It's not up to the manufacturer. These turbines are not built for that [ramping them up and down]. Larger turbines are pitch controlled. So, it was due to the negative electricity prices.”

Wholesale power prices in much of northern Europe fell into negative territory on Sunday as high solar irradiation and strong winds flooded power grids – reaching electricity prices of minus €500/MWh in Germany for a short time.

Germany in times of excess renewable energy production usually exports electricity to its neighbours or curtails wind farms, which costs taxpayers billions of euros every year.

The damaged turbine was a Nordex N43-600kW. The Stemwede wind farm was built in 1998 and not serviced by Nordex any longer. The company couldn’t immediately comment when approached by Recharge.