Hermanville wind turbine demolished, 3 others being repaired

One of the turbines at the wind farm in Hermanville was demolished Tuesday in earth-rattling fashion after a wind storm late last year compromised its foundation.

Another turbine at the eastern P.E.I. wind farm is being refurbished, and two more are running at half-capacity to fix common, but "long-standing systemic issues," provincial officials said. 

Blair Arsenault, operations engineer for the P.E.I. Energy Corporation, said part of the repair work is called "root-facing," a common refitting that involves flattening the blades to keep their studs from breaking.

Heavy winds during a storm back in December tore two blades off of Turbine 9. That and other damage caused by the storm ultimately led to Tuesday's demolition, Arsenault said.

"One of the pitch ram heads broke off ... and then the turbine spun out of control in a storm and [that] compromised the foundation," he said,

The turbine began to lean, Arsenault said, and at that point it would have been unsafe to repair it without taking it down.

"From a safety perspective, that's why it had to be demolished."

How do you demolish a wind turbine?

The answer is dynamite.

Preparing to fell a turbine is a bit like felling a tree. Arsenault said workers cut into one side of the structure, so when the dynamite explodes, the turbine topples exactly where they want it to.

As for the cleanup operation, all the metal and fibreglass will be recycled. The province's Department of Environment will then visit the site to make sure there are no lingering environmental risks. 

"Then we'll start the process of getting a new turbine."

1 turbine being repaired, 2 more at half-capacity

In addition to the demolished turbine, three others at the farm are being refitted.

One is currently on the ground so crews can install a new main shaft assembly. After the grounded turbine is fixed up, the other two will get a similar treatment.

Arsenault said the province is paying for the repairs, but the Hermanville farm has generated over $20 million in energy so far.

"We're not out of pocket, by any means," he said. "This farm is profitable, so we're just using some of that profit."

He's confident the repairs will be worth it.

"We haven't broken a single blade stud since we did this root-facing," Arsenault said, referring to similar upgrades done on two turbines last year.

"Significant events with wind turbines, they happen. You just have to move forward and [fix] it and get things going again."

According to a news release from the province, the Hermanville wind farm has provided the Island with 881,705 megawatt hours of electricity.