Component failures have led to a drop in quality in onshore wind turbines that could cost more than €1 billion to fix, Siemens Energy boss Christian Bruch admitted in an announcement that wiped a third off the company’s market value.

While quality is not yet a concern for offshore wind, slow ramp-up and other challenges have led to unsustainable losses that cannot continue, the firm admits.

“These quality problems go beyond what we were previously aware of and are directly linked to selected components and a few but important suppliers.”