Germany's Enercon on Monday said a "massive disruption" of satellite connections in Europe was affecting the operations of 5,800 wind turbines in central Europe.
It said the satellite connections stopped working on Thursday, knocking out remote monitoring and control of the wind turbines, which have a total capacity of 11 gigawatt (GW).
"The exact cause of the disruption is not yet known. The communication services failed almost simultaneously with the start of the Russian invasion of Ukraine," Enercon said in a statement.
The company said it had no further information on who or what may have caused the disruption.
Enercon has informed Germany's cybersecurity watchdog BSI and is working with the relevant providers of the satellite communication networks to resolve the disruption, which it said affected around 30,000 satellite terminals used by companies and organisations from various sectors across Europe.