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More Wind Power for Minnesota Power

Minnesota Power has completed commissioning of the latest phase of its Bison Wind Energy Center. The 205-megawatt expansion, built by Wanzek Construction, makes it the largest wind farm in North Dakota and ranks Minnesota Power as one of America's Top-10

By Diane Mettler

Minnesota Power's successful 205-megawatt expansion of its Bison Wind Energy Center (Bison 4) makes it the largest wind farm in North Dakota and ranks Minnesota Power as one of America's Top-10 wind power-owning electric utilities.

Behind every successful wind project is a talented and skilled construction team. In this case, the construction company was Wanzek Construction, which was contracted by Minnesota Power to handle the collection system, roads, and foundations. They were also subcontracted by Siemens to erect their 3.2MW direct drive turbines.

Siemens and Wanzek were hardly strangers when they started the project. Wanzek had erected many Siemens turbines over the years, but Rob Lee, operations manager of Wanzek's Wind Energy Projects, says, "This was the first time we had been contracted by them. And it was the first time we'd installed the Siemens 3.2MW direct drive turbines."

When Wanzek broke ground in October 2013, the first step was to build miles of roads. Bison 4 encompasses 35 square miles with 20 miles between the most eastern and most western turbines. It would take approximately 14 miles of new roads and upgrades to 11 miles of existing roads to make the installation of the 64 turbines possible.

"We started with the roads in 2013 and had plans to pour quite a few foundations at that time too," says Lee. "But during the fall of 2013, the weather became pretty adverse. We had a lot of rain and then a really early freeze."

In early 2014, Wanzek put together a solid plan to make sure they met Minnesota Power's schedule, and to get ahead of the turbines being delivered.

"Again, we got hit with a lot of adverse weather, while we were building roads and foundations, and it slowed us down a number of times. But we just worked through it," says Lee.

"With a lot of rain, there's really no way to work around it," he added. "You can de-water and try to dry it out by multiple different methods, but that only happens after the rain has quit. Sometimes on the Bison 4 Project it seemed like the spigots never got turned off."

The rain wasn't Wanzek's only weather problem on the project. During the turbine erection, they had to battle some extraordinary windstorms, which blew through the area causing major problems. To get an idea of the force, the winds tipped over a couple of Wanzek's side-by-side four-wheelers.

 
  

To stay on top of it all, the Wanzek crew had to remain flexible and re-align quickly.

"We had straight line winds over 100 miles-an-hour twice on that project, and I think that's fairly rare in North Dakota," says Lee. "The heavy winds did cause some damage, and we had to get together as a team (Wanzek, Siemens, and Minnesota Power) and find out the best path to moving forward."

Together, Wanzek worked with Siemens to minimize the impacts as much as possible by moving cranes to the turbines that were ready to be erected. "You just have to re-think your whole plan and move forward with the options that are presented to you," says Lee. "And I think Siemens and Wanzek worked really well to continue moving forward with what was put in front of us."

Luckily, despite the severe wind and weather, the project continued on safely.

An additional challenge was working with a new turbine—the Siemens 3.2MW direct drive—although this was the kind of challenge for which Wanzek was well prepared.

"Each turbine we assemble has its specific challenges. Driving past them, they may all look very similar, but they are each very different to assemble.

"We have gained valuable experience through the years with many different turbine manufacturers, and we understand that we will have a learning curve on each turbine model that we are contracted to assemble," says Lee. "We have systems and procedures on each new turbine that we walk through to make sure we are educated on the intricacies of the turbine. This allows us to assure the owner and turbine manufacturer that we will be assembling it to the manufacturer's installation guidelines."

 
Despite torrential rains and severe windstorms-Wanzek Construction dealt with straight line winds over 100 miles-an-hour twice on the Bison 4 wind project-construction of Bison 4 was completed on time. The renewable energy now generated by Bison 4 is transmitted to Minnesota Power's Arrowhead Substation near Duluth, Minnesota. 
  

These particular Siemens wind turbine generators were more powerful than those installed in earlier phases of the project. Because they are more powerful generators, it only took 64 turbines to produce about the same amount of electricity produced by the 70 turbines installed for Bison 2 and 3.

There is no escaping the cold during North Dakota winters, but cold isn't a big factor, says Lee. "We can usually work through the winter; it just depends on what type of construction you're looking for. It froze [during Bison 4] and we continued on with erection. Cold weather presents certain challenges but you can erect turbines."

However, it can get too cold to go on. "When it gets to a steady temperature of below freezing 24 hours a day, then it starts to get too cold to continue on for the safety of our personnel."

When it was all complete, the Wanzek crew had:

Erected 64 turbines, totaling 205 MW.

Built 75,000 feet of new roads.

Performed four full de-rig mobilizations of the main crane (approximately 30 loads each).

Installed 282,624 linear feet of collection line.

The Wanzek construction team was mostly homegrown. Since the Bison project was on Wanzek's turf (Wanzek is headquartered in Fargo, North Dakota), they were able to hire a lot of folks close to home. At peak construction there were around 150 people on site.

 
  

"It's pretty special to be a part of Bison 4 because we hadn't really built any wind farms in North Dakota over the past few years. When we have the opportunity to build a wind farm in North Dakota, we try to take advantage of that opportunity," says Lee.

Despite the severe windstorms and torrential rains, the project was completed on time. It was up and running and producing power by December 20. The renewable energy generated is transmitted to Minnesota Power's Arrowhead Substation near Duluth, Minnesota.

"It was probably one of the more difficult projects we've ever done in terms of weather and the conditions that we had to work through. But ultimately, we worked through it and got the job done," says Lee.

Although this was the first time Wanzek and Siemens had worked together, it turned out to be a good collaboration. The two companies continue to talk and are looking at an upcoming project. "It's a relationship we're hoping will grow over the next year," says Lee.

The project didn't stop with the turbines. Wanzek also makes a point to give back to the communities they work in. Lee says that they talk to the Chambers of Commerce, local mayors, or county commissioners to see what there is out there that might need to be done.

"On this project, we poured a slab for the fairgrounds. We also contributed a donation to the Missouri Slope United Way," says Lee. He adds the contributions are almost never the same thing. "We've done everything from improving a skateboard ramp park to, one time, we bought a jaws of life for the local EMT service. We're guests in these communities, and we try to reach out to each of them and let them know that we appreciate being welcomed."

With Bison 4 behind them, Wanzek is currently involved in a number of new projects. As one of the bigger wind energy contractors in the U.S., having built about 6,500 megawatts of wind, you tend to stay busy.

"We are actively engaged in one stage or another on roughly ten projects right now," says Lee. Those projects include startups to close-outs and everything in between.

Another thing keeping them busy is Wanzek O&M Services, which they launched in the last four years. This branch of the company helps existing wind farms in a variety of ways. "One aspect is upgrading or replacing large components on wind turbines to keep them running efficiently," says Lee.

Right now, the company is optimistic about wind's future, in part because of the PTC (production tax credit). "That's the driver of our industry right now," says Lee. "Hopefully, one day it won't be, but currently the PTC still drives our industry. From talking with people who know what's going on at Capitol Hill, we have a very good outlook that the PTC will continue to be extended, and that will mean all kinds of work for years to come."

 


September/October 2015