The Massachusetts Water Resource Authority has reiterated its claim that the Charlestown wind turbine with its floating foundation that has been sinking remains safe and has been constructed with a safety factor twice that of which is required.
“While the structure has settled, it remains level and plumb with all components remaining operationally ready,” according to the MWRA’s Ria Convery.
As reported last week, the new wind turbine in Charlestown has apparently sunk about 2 inches causing significant worry that the structural integrity of the 426,000 pound turbine is at risk.
The turbine, which rises 364 feet into the air at the tip of its extended blades, has a foundation 25 feet deep and 5 feet across. It cost $4.7 million to build and has not been generating electricity since the beginning of January.
MWRA authorities have declared there is no danger of the turbine falling over or taking on a lean but that the rate of sinkage experienced as noted is of concern.
The 231 ton turbine stands on land occupied by the DeLauri Sewer Pump Station off Route 99 – where the Charlestown/Boston demarcation line is shared with Everett near to the Mystic River.
The towering wind turbine is impossible to miss for all those traveling into Boston from Everett and out of Boston into Everett on Rt. 99.
“Convery said it is important to note that this type of floating foundation is very common for wind turbines around the world.
During scheduled maintenance it was determined that the foundation had indeed settled.
“While some settling and re-torquing of the bolts that tie the foundation to its anchors had been expected, the settling exceeded what was anticipated,” added Convery.
Lumus Construction built the turbine, which is a state of the art green-energy venue.
City Councillor Sal LaMattina, who represents Charlestown, told the Patriot-Bridge that he was certain the turbine’s foundation would be repaired. He said he had been told the shoring up of the soil the turbine’s foundation is built on will begin next week.
Officials said grout will most likely be injected into the foundation area to make it more firm.
“I support projects like these because this is what we need to be doing to become energy independent,” said LaMattina. “It is projects like this one that help us to generate electricity without having to pay for energy to drive the turbine itself. This is the way to go. Wind generated power is about the future,” he said.
The MWRA sells electricity generated by the Charlestown wind turbine when it is running to the Deer Island sewage treatment plant.
The blades for the turbine were produced in China and sent by boat to the US and off-loaded in Chelsea and then trucked to Charlestown.
MWRA officials did not know exactly why the rate of sinkage has been so great except to surmise that soil conditions and vibrations from a sudden shutdown triggered by high winds might be the causes.
“The engineers have determined that it is prudent to stiffen or reinforce the foundation before the turbine is restarted. The contractor has submitted options for his work which are under consideration,” Convery said.
“The work falls under warranty,” she added.