Nearly all of the 22 turbine foundations at Nova Scotia Power’s Nuttby Mountain wind farm are cracked, CBC News has learned.
“Wherever we identify cracks, they are being addressed. I think right now we are at 19 of the 22,” NSP spokesman David Rodenhiser said Tuesday.
The problem came to light late last year when it was discovered five of the towers were moving beyond manufacturers specifications. During construction last July at the $120-million wind farm, concrete was not vibrated down to the steel base of the towers.
Movement with the remaining towers is within acceptable tolerance levels, Rodenhiser said, but NSP decided to repair them anyway.
“We’ve found some cracking in some of the other foundations …we decided the most prudent measure was to address those as well,” he said.
The repairs involve injecting an epoxy-like sealant into the 400-tonne concrete pads to stabilize the concrete.
The German supplier, Enercon Canada Inc., supplied the turbines and is paying for the repairs, which are covered under warranty.
“It is my understanding that there was vibration and tamping that did not get done to the extent that the concrete settled all the way to the bottom of the steel,” Rodenhiser said.
It will be well into March at the earliest, before the repairs are completed.
As the foundations are repaired, towers will be brought into service generating electricity for the provincial grid.
“There have been towers taken out of service while these repairs are done, and then once the repairs are completed, the towers are brought back into service,” Rodenhiser said.