Photo: Jackie Shumaker

The delicate grace of the assembled windmills belies their massive girth. The 262.5-ft-tall hollow supporting towers are 15 ft in diameter. Each weighs in at 470,000 lb.

Photo: Jackie Shumaker

RES Americas used a 650-ton crawler crane to erect the wind towers. The cell weight, 85,000 lb., dictates the size of the crane.

Photo: Jackie Shumakere

The General Electric-manufactured 1.5-mw turbines feature three-bladed rotors that are 252.6 ft long. The crane capacity allowed the contractor to make lifts despite winds that often exceeded 22 mph.

The $245.5-million High Plains project has 66 General Electric, 1.5-mw turbines with a 99-mw generating capability. The $60.5-million McFadden farm has 19 turbines and a generating capability of 28.5 mw.

RES Americas of Broomfield, Colo., worked through last winter to deliver High Plains three months ahead of schedule and McFadden one month early so both projects could go online in September for owner PacifiCorp of Portland, Ore.

�Without intense management and cooperation of everyone involved � PacifiCorp, contractors, the turbine supplier and RES � we would not have come in early,� says Jason Zingerman, vice president of construction projects for RES Americas� northwest region. �Our subcontractors were cooperative. When they saw others were coming in early, they followed.�

RES Americas, one of the top renewable energy companies in the country, has been active in North America since 1997. The contractor usually imports some management but finds most of its labor locally.

�We are starting to get a good pool of labor in that area that is talented in windfarm construction,� Zingerman says.

Although RES Americas specializes in every aspect of developing, constructing, owning and operating renewable-energy projects, on High Plains and McFadden Ridge it was the balance-of-plant contractor.

�PacifiCorp purchased the wind turbines, did design and site location,� Zingerman says. �We erected, assembled them and made them ready for use.�

Although the capital costs are public information, the owner would not disclose the RES contract amount.

The same day the contract was signed in October 2008, RES began construction of 20 miles of gravel roads required to access each site and deliver materials, Zingerman says.

�We had to get those roads in before winter, and we had to have winter delivery of the turbines, which is unusual,� he adds.

The winter work is part of PacifiCorp�s aggressive schedule to meet resource demand in the service area, says David Eskelsen, the company�s spokesperson. �Wyoming, Utah and Idaho are still growing despite the economic downturn. We have asked developers and contractors working on projects to help us make sure we have the capacity we need to serve our customers.�

RES Americas took delivery of the GE turbines in January. The turbines consist of three-bladed rotors, 252.6 ft in diameter; a power cell; and a 262.5-ft-tall, hollow steel, supporting tower 15 ft in diameter.

The GE proprietary blades are made of a composite material. The towers were shipped in three pieces. �These are massive, and you don�t realize it until you stand next to one,� Zingerman says.

To help the components weather the winter, the contractor placed them on cribbing to avoid contact with ground moisture and used tarps for cover. Maintenance was required throughout the winter months to keep the parts dry.

Some Assembly Required

In addition to erecting the turbines, RES constructed 23 miles of underground electrical cabling that connects the turbines. �We also built a substation to step the voltage up, and we built a 10.5-mile transmission line to get it to the grid,� Zingerman says.

In the spring, the contractor began concurrently installing the underground electrical system, constructing foundations and erecting the turbines. A batch plant was set up onsite to provide the 240 yd of concrete required for each 45-ft octagonal foundation. About 25 tons of rebar were used in each foundation.

The towers and cell were assembled with bolted connections. Total weight of the turbines is 470,000 lb. The heaviest pieces are the 85,000-lb cells. For the lifts, RES Americas used a 650-ton crawler crane.

�It was a little oversized, which helped us a lot in windy Wyoming conditions,� Zingerman says. �The height and weight of the cell is what governs the size of the equipment. Plus, you�ve got multiple lifts on a single location, so you have to walk the crane from location to location several times per day.�

In addition to the 650-ton crawler, RES used several smaller cranes to offload parts from trucks and assist in erecting the tower sections. �We have strict wind limits for lifting, and there were times we couldn�t lift,� Zingerman says. Nearly 22 mph winds would mean halting a lift, and that�s quite common in that area, he says.

Although the winter schedule was unusual, it worked in the contractor�s favor. �When May 1 came around, we had everything onsite and ready to go,� Zingerman says.

As an additional green element to this sustainable project, RES reclaimed and reseeded the site. �We brought it back to the smallest footprint that will still allow for operations,� Zingerman says.

Once the project was complete, cattle on the two ranchland properties were allowed to roam freely among the turbines.

PacifiCorp has completed nine new wind projects during the past two years, seven of which are located in Wyoming.