Trains, trucks, and ships make wind energy possible

by Katie Greenwood

Imagine yourself in a flat, wide-open field. Next to you, extending about 400 feet into the air is a wind turbine. Its 3 gigantic steel blades whoosh around and around hundreds of feet above your head.

Standing next to a wind turbine, you can witness the incredible power of the wind to move this massive machine.

But before the wind could move the turbine, something else had to move it first.

Trucks, ships, and trains move wind turbines from the factory to the wind farm. A wind farm is a group of wind turbines in the same location used to produce electricity. (Wind farms are also called wind power plants.)

In the United States, Texas and Iowa have the greatest number of wind farms because flat plains are the best sites for wind farms, but many turbines come from factories outside of the United States.

Just how big are they?

Wind farms range in size from a few dozen to 421 turbines. A single turbine is transported in up to 12 pieces.

Wind turbines are manufactured and shipped in several parts, and each part is huge.

The tall, vertical piece is called the tower. It's usually made in 3 parts but sometimes more.

Each section of the tower is about 120 feet long and weighs up to 70 tons. An empty semi-truck and trailer weighs about 15 tons.

Attached to the top of the tower is the nacelle. The nacelle houses the generator, power electronics, and the gears that turn the wind into electrical energy. Nacelles weigh 50–70 tons.

Most turbines have 3 blades that are attached to the nacelle by the rotor hub. Some blades are up to 50 yards long. A 3-blade rotor hub can almost cover a football field!

Curriculum connection

Using geometry in a transport route survey

Before construction of a land wind farm can begin, route planners consider several possible trucking routes for the turbines.

Route planners study several factors including traffic, road construction, surrounding buildings, and environmental issues to determine the best route.

With the help of a surveyor, the route planner assesses the steepness of hills and inclines along the route. A surveyor can take the necessary measurements using a transit.

Students practice using
a surveyor's transit.

The steepness of a road's incline is called the grade. Turbines can safely ascend and descend grades of less than 15%. Steeper grades can potentially lead to accidents that damage turbine parts or cause erosion of the soil and structure beneath the road.

If the surveyor assesses the grade at greater than 15%, it may be necessary to level the roads or put in erosion control measures for that part of the route.

Getting the grade

How do they get the grade?

The illustration below shows a highway in profile. Notice that a right triangle has been constructed in the diagram.

An illustration of the the verticle and horizontal distances of an inclined road.

The bottom of the triangle is the horizontal distance a particular section of highway covers. This horizontal distance, or the “run” of the highway, indicates how far a vehicle would travel on the road if it were level.

The “rise,” or vertical distance, is a measure of how much higher a vehicle is after driving along the road. To find the “rise,” the surveyor must determine the difference in elevation from the bottom of a slope to the top.

Putting it together

Similar to calculating the slope of a line in your geometry class, calculating the incline of a road is simply “rise over run.”

Slope is the measure of the vertical rise in the road divided by the horizontal distance or:

s=y/x

Grade is the slope expressed as a percentage. To find the percent, the slope is multiplied by 100.

G=100s

Try it out: If a highway rises 375 feet over 1 mile, is the grade safe for trucks hauling turbine components?

Check your answer.

So to build even small wind farms, there are many large loads that must travel long distances.

How in the world are these hulking parts moved?

The type of transportation used depends on the location of the wind farm. Often, a combination of transportation modes is used for each wind farm.

By train

A large number of turbines manufactured in the United States are first transported by train, according to Dr. Nadia Gkritza, who is currently researching sustainable energy and transportation systems at Iowa State University.

A single train can haul 50–70 cars of wind turbine parts. Photo courtesy: kedziers via flickr

A single train can haul 50–70 cars of wind turbine parts. It costs less to move turbine parts by train because more can be moved at a time, but the train routes must avoid low overpasses when hauling the large components.

But since trains don't directly connect to the wind farms, the final transportation leg must be done by truck.

By trucks

Trucking has been the most common method of transporting turbines because trucks can go directly to a wind farm.

Each wind turbine requires 8–12 semi-truck trailers. Many turbine loads weigh more than 100,000 pounds. Photo courtesy: Bill Weaver via flickr

Transporting by truck requires 8–12 trailers for each turbine.

Hauling the oversized loads requires a permit from the state Department of Transportation. The trucks must follow paths that avoid road construction, low bridges, and busy city centers. Often, trucks have to take a long route to their destination when transporting turbines.

Many wind farms are located within crop farmland. This means that these heavy parts travel on narrow, unpaved roads that are not designed to accommodate the heavy loads. Immediately after a wind farm is completed, maintenance workers must repair and level the roads.

Highways and interstates can handle about 80,000 pounds. Many turbine loads weigh more than 100,000 pounds, so transporting turbines can cause damage to even these roads over time.

By ships

When turbine components come from overseas, they are imported in several shipments. Each ship carries only 1 type of component.

When Vestas imported 60 turbines into the Port of Longview in Washington, all the components arrived in 5 shipments. The towers arrived in 3 separate shipments followed by 2 shipments of nacelles and blades.

The fragile loads must be packed tightly but carefully to avoid damage. Safety must also be considered to avoid interfering with the ship’s stability and navigation.

There are specific ways of lashing and securing the parts to the ship. When shipped long distance, blades are shipped in transport containers to keep them from shifting around.

As wind energy technology advances, new wind farms are being erected off shore. An offshore wind farm in Nantucket Sound, Massachusetts, is scheduled to begin in 2010. The project is being called Cape Wind.

One advantage to transporting by ships and barges: they don’t have to negotiate tight turns or avoid overpasses like trucks and trains.

Learn More

The American Wind Energy Association offers an excellent wind energy tutorial that discusses the basics of wind power.

Katie Greenwood is a writer for Go!.

Comments (1)

Dec 20, 2009 Michael Manis -NY writes

I believe that wind energy is a partial answer to our country's oil dependency. We need to establish wind farms off shores of America and get this going. We need to show this Arabs that we mean buisness. This country was able to land a man on the moon and win two world wars but is reluctant to take the right move on GREEN energy. Michael Manis-Jericho NY

Go! is brought to you through the generous donations and grants of our sponsors, including these platinum-level sponsors: the Iowa Math and Science Education Partnership, the Federal Highway Administration, and the Midwest Transportation Consortium.

Learn more about all our sponsors.