New O'Brien Wind Farm Progressing Rapidly

By Loren Flaugh

Photo by Loren Flaugh

The pace of progress on MidAmerican Energy Company's (MEC) 250 megawatt (MW) O'Brien Wind Energy Project in north central O'Brien County's Franklin, Lincoln and Center Townships around Sanborn has increased. Mortenson Construction Company is building theisecond major wind farm in the county.

Chicago-based wind energy developer, Invenergy LLC, began developing the O'Brien project in 2007 when affected landowners started signing lucrative wind energy leases. On August 18, 2015 the public hearing for approving the wind farm construction permit was held in Primghar where approval was granted. At this public hearing, Invenergy announced that the project was transferred to MEC for construction and ownership.

MEC initially announced on May 1, 2015 that it had filed plans with the Iowa Utilities Board for the development of up to 552 MW of new wind energy in its "Wind X" expansion program with one wind farm planned for O'Brien County and a 300 MW wind farm in Ida County. MEC said the total cost for both wind farms could approach $900 million.

In its press release issued on August 21, 2015, the Iowa Utilities Board said they issued their approval for the project with the stipulation that MEC would be subjected to a cost cap of $1.638 million per MW. The IUB noted, in part, "This lower cap reduces the risk to customers and provides an incentive to keep costs low."

The project is divided into 6 zones. Mortenson has the cement foundations in zones 1 through 5 in Franklin and Lincoln Townships largely completed. Construction crews are now focused on zone 6 in Center Township east of Highway 59 and south of Highway 18 installing 96,000 pounds of rebar, building forms and pouring over 50 truckloads of cement in each foundation.

Mortenson brought in four giant cranes for assembling the 104 wind turbine sites. The cranes were brought into the wind farm project north of Highway 18 and 3 miles west of Sanborn.

Just like when Mortenson assembled the 214 wind turbines in the 502 MW Highland Wind Farm last year, they will utilize 2 giant Manitowoc 16,000 cranes with 300 feet of boom to lift the 118-foot long top tube section, the 191,000-pound Siemens nacelle and the hub and blades as one assembly. Two smaller cranes with a lower lifting capacity will lift the bottom two tube sections and attach the three 173- foot long blades to the hub next to the base.

For Siemens, the logistics of scheduling wind turbine components for timely delivery to the project site and then moving so many over-sized loads on the nation's highways is a monumental challenge. The Siemens logistics schedule called for delivering components for 9 complete wind turbine sites per week. Turbine components started accumulating at the receiving yard during the week July 18 and will continue well into late October.

Each wind turbine site consists of a 54-foot long base tower tube section, an 85-foot long mid- tower tube section, a 118-foot long top tower tube section, the 193,000-pound Siemens nacelle, the 64,154-pound hub and the three 173-foot long blades each weighing 24,855 pounds. One complete turbine site consists of 10 to 11 truckloads with 7 of the truckloads considered as super-loads.

All 312 blades come from the Siemens blade manufacturing facility at Fort Madison, Iowa. The blades are routed north to Highway 20 near Waterloo, then west to Highway 59 and north through downtown Cherokee to the receiving yard south of Primghar.

The 193,000 pound nacelles are manufactured in central Kansas at Hutchinson. The 104 trucks are routed from Hutchinson to Omaha, then across the Missouri River, where they follow Highway 59 north through Cherokee to the delivery yard. These massive Emmert International trucks have 19 axles and are 195 feet in length. The 64,000-pound hubs are routed much the same, with one hub carried per load.

Some tube sections are manufactured at the Broadwind Energy facility at Manitowoc, Wisconsin along northern Lake Michigan. These heavy-duty trucks are routed on a meandering path southwest through Wisconsin and Illinois to Davenport, Iowa. From Davenport, the Iowa Department of Transportation routes them on Interstate 80 to Iowa City and then north to Waterloo onto Highway 20 going west to Highway 59. Once again, more heavy super-loads will pass through downtown Cherokee going to the receiving yard south of Primghar.

Marmen Energy, a Canadian steel fabrication company, recently built a heavy steel fabrication facility located in Brandon east of Sioux Falls. The heavy-duty trucks carrying the steel tube sections manufactured at Brandon will follow Interstate 29 south out of Sioux Falls, turn east onto Highway 18 to Highway 59 in O'Brien County and then south through Primghar to the receiving yard.

With construction underway at MEC's 300 MW Ida County wind farm, turbine components destined for that wind farm will be on Iowa's roads probably using mostly the same routes. And, it could happen that tube sections built at the Marmen Energy facility might be routed south on Highway 59 through downtown Cherokee to Ida County while turbine components destined for O'Brien County are moving north through Cherokee.

This story first appeared in the Chronicle Times. Click Here to read the article on their website.