By Sarah Doty
Post-Bulletin, Rochester MN
DEXTER -- The turbines that surround the town of Dexter can be seen spinning -- most of the time -- from miles away.
But if they aren't, the responsibility of making sure they are fixed falls mostly on the shoulders of Kurt Christensen, operations manager for enXco, and his staff.
Christensen is in charge of both the Wapsipinicon Wind Project, just north of Interstate 90 near Dexter, and the Grand Meadow Wind Farm just south of I-90.
Those two farms each have 67 turbines and together generate 201 megawatts of energy. Six technicians, one manager and one supervisor are constantly on site doing various sorts of maintenance to keep those 134 turbines spinning.
"What we do is we have three different phases (of maintenance)," said Christensen. "When we take the towers over, we do what we call break-in maintenance. Then you have a semi-annual maintenance and an annual maintenance."
During the break-in maintenance, Christensen says the technicians go through each tower and "physically wrench on and check 100 percent (more than 600 bolts) of the structural bolts in the whole tower." They also take oil samples from the gear box and generator alignment.
"What we are doing is making sure everything through the construction phase was done correctly and is double-checked," he said.
During the semi-annual and annual maintenance, the towers are also inspected, this time with a 10 percent bolt check. However, if even one bolt is found to be loose, the technicians will then check all of the bolts in that area, Christensen said.
Between the maintenance cycles, the technicians are working on fixing kinks or problems that might arise just with standard wear and tear of the machine.
It is no small project considering a turbine has hundreds and probably even thousands of components.
It is that detail that sometimes has left members of his team frustrated, said Christensen. But he tries to put it into perspective for them.
"I keep trying to tell them ... if you go through 67 turbines and you look at all the different parts and actions that are there on a turbine whether it be mechanical or electrical or on and on and on, and you combine that; there is probably 10 million things that could go wrong," he said.
Even with a small percentage rate of error, Christensen and his team might find thousands of things that need to be fixed because of the number of turbines and parts.
"Things are going to happen," he said. "Frankly, guess what? If they didn't, I wouldn't have a job, so it's OK."