February 2019. 51MW Casa Mesa Wind Energy Center, New Mexico. Turbine: GE 2.5-127. Operator: NextEra Energy.

Ed Hall on what we know: “A combination of multiple factors while the turbine was in operation. A mechanical issue combined with an electrical issue led to the control system being a little slow to respond, the turbine progressed to an unstable operation and ultimately a blade struck the tower.”

May 2019: 65MW Chisholm View 2, Oklahoma. Turbine: GE 2.4-107. Operator: Enel Green Power.

What we know: “During the restart of a turbine, a hard reboot was performed. During the reboot while some of the protection systems were still coming online, the turbine progressed to an unstable operating condition.”

July 2019: 200MW Upstream Wind Energy Center, Nebraska. Turbine: GE 2.5-116. Operator: Invenergy.

What we know: “A blade that was damaged prior to installation was evaluated and repaired using our standard procedures. What was unknown was that there was additional damage hidden inside the blade that was not detected and that damage ultimately resulted in a crack and the blade detached near the point of repair. Under high wind operating conditions, that led to an imbalance and overwhelmed the tower.”

July 2019: 216MW Ventos de São Clemente wind complex, Pernambuco, Brazil. Turbine: GE 1.7-103. Operator: Echoenergia.

What we know: “The turbine had been operating for some time and in the course of that operation a crack developed in the blade. It was not detected during normal inspections, and ultimately grew larger and resulted in the blade detaching.”

September 2019: 54MW Delta 6 wind park, Maranhao, Brazil. Turbine: GE 2.7-116. Operator: Omega.

What we know: “It’s too early to comment or speculate on the root cause. It’s known technicians were at the turbine and performing some service on the turbine at the time. One of the technicians was injured and we’re doing everything we can to support that person and his family.”

Top GE engineer lifts lid on wind turbine collapse probe findings