An 18-foot concrete pedestal, 177-foot blades and every part in between were on the ground and available for area residents to see up close and learn about as MidAmerican Energy courted its current and potential wind energy conversion customers Saturday at the Orient wind farm in Adair County.
MidAmerican, Vestas and Blattner Energy representatives were on-hand to answer questions about the structure, function and safety of the wind turbines.
A representative of Blattner Energy explained that the 18-foot pedestal is actually the top of a 65- to 70-foot concrete base built with 35 to 40 tons of rebar that weighs up to 2 million pounds to support the weight of the turbine and give it stability.
Vestas employees, the company that is building and maintaining the turbines at Orient 1, were stationed at each piece of the wind turbine. At one tower section, an employee of Vestas spoke of the ladder inside the tower which allows maintenance staff to climb to the top. Each section of ladder has a platform at the top where workers can inspect the bolts that secure the sections together.
According to the Vestas representative, the ladders form a straight line up to the top instead of being staggered around the interior. Workers who climb the ladders are attached to a safety cable which tightens automatically if the worker begins to free-fall.
Austin Davis, a Vestas employee, pointed out several “dots” near the tip of each blade that are actually metal plugs connected to a cable that runs deep into the ground to conduct lightning. Davis said, before conductors were designed into the turbines, a lightning strike often caused major damage. Now, with the conductors, damage is usually repairable without dismantling the turbine.
Davis said lightning striking a turbine is rare. The Orient wind farm has been operating for approximately one year and has had no lightning strikes. If one did occur, the turbines have sensors that will automatically shut them down until an onsite inspection can be made.
Drones can be used to inspect the blades or a worker can be hoisted in a “man basket” that will reach up to allow them to see any damage. If necessary, the blades can be taken down for closer inspection or repair.
Many of those attending had already signed contracts for turbines and/or other types of access to their land.
Randy, Josh and Blake Cooper, who each own land in Adams County, have rented air space to MidAmerican and hope to have turbines placed on their properties. Blake said the company is currently surveying the land and has one area on his farm staked out as a potential site for a turbine.
Sara Crook, a landowner in Orient, said signing up for three turbines to be built on her land was not difficult. It was an easy decision to make, she said.