Six of 10 turbines at P.E.I.'s East Point Wind Plant have been shut down to avoid further damage after problems with their gearboxes were discovered during routine inspections.

'This is not something that is just specific to P.E.I.'— Ron Estabrooks, P.E.I. Energy Corporation

The three-megawatt, 90-metre turbines are the largest wind turbines in commercial operation in North America, said Vestas Americas, suppliers of the turbines, in a news release Tuesday.

"The technology is still new, and it is a key focus area of ours to continuously develop and improve the reliability of our products," said president Jens Soby.

Under its agreement with the P.E.I. Energy Corporation, the Crown corporation that owns and operates the wind farm, Vestas, will be responsible for repairs and lost revenue during the outage, including payments to landowners where the turbines are situated.

Ron Estabrooks, energy adviser with the P.E.I. Energy Corporation, told CBC News on Tuesday that their first thought was the turbines simply couldn't handle the amount of wind at East Point.

"They have revealed to us that they have seen the same problem in their European models. So this is not something that is just specific to P.E.I.," said Estabrooks.

"It appears that they are experiencing that problem with the other locations where the V90s are situated."

The exact problem hasn't been diagnosed yet, said Estabrooks, but his understanding is it is a problem with the bearings.

Replacement gearboxes are now being delivered to the wind plant. The spring weight restriction on Island roads delayed the repairs.

Transport of a large-capacity crane required to remove and replace gearboxes at the top of the turbines was not possible until the restrictions were lifted.

Repairs are expected to be completed by the end of June.