Turbines now turning on the Texas Coast

Mortenson Construction recently wrap-ped up work on Iberdrola Renewables' Penascal II wind farm on the Texas coast, a project that involved adverse weather conditions during construction, including hurricane-type weather.

By Paul MacDonald

Just a few hours west of where one of the largest environmental disasters in U.S. history

occurred this past summer off the Louisiana coast-the BP oil well spill-the bright future and innovation of the American wind power industry continues to unfold.

At a time when the BP spill was on the front pages of newspapers across the country, one of the leading wind power companies in the world, Iberdrola Renewables began commercial operations of the Penascal II wind farm, on the Texas coast. The contrast of clean energy with fossil fuels could not have been clearer.

	During the erection process on Penascal II, Mortenson Construction established multiple work shifts, and crews were often working from midnight right through to the next morning because the weather conditions were good for erecting the turbines.

One of the leading wind power construction firms in the U.S., Mortenson Construction, built the

Penascal II project that, combined with the Penascal I project, is a massive 404 Megawatts.

The wind farm site is in Kenedy County, on the western tip of the most southern point of Texas. It sits right on the Gulf of Mexico, about 25 miles from the nearest highway.

Penascal has an attribute common to many Texas wind farms-it is in a lightly populated area. In fact, Kenedy County reportedly has the distinction of having the fourth lowest-population of any county in the United States. It actually has more square miles than people.

The Penascal II project, being close to the coast and fairly remote, carried its own set of challenges in terms of construction, says Tim Maag, vice president and general manager of Mortenson's Renewable Energy Group. Maag has a concise description of the site. "The terrain can best be described as sand, sand, and more sand-and add to that, blowing sand." In terms of logistics, its location also posed challenges. "It's a very remote site," says Maag.

There is not a lot of grade change from one end of the 15,000 acre site to the other, so it's fairly straightforward in that respect. "But in addition to the remote location, we had extreme heat. And since it was on the coast, we battled heavy rains that sometimes created flood-like conditions. And there is a great wind resource there, so we also battled high winds."

The Penascal project, in many respects, was the opposite of some other projects Mortenson had worked on in the Midwest Wind Buckle. In locations such as Minnesota, Mortenson's home state, they routinely deal with extreme cold and snow. More often than not, these projects are fairly close to county roads and regional highways, so the haul in to the wind farm site is much more limited.

Having visited the Penascal site in advance, and researched the area, Mortenson knew exactly what they were in for: a tough job.

"We understood what the challenges were," says Maag. "We pre-planned the Penascal project, and we developed a very specific plan that included a comprehensive safety plan on how we were going to keep our workers safe from the blowing sand. And if hurricane-like conditions came in, we knew what our emergency response plan would be to make sure that all the trades people and team members would be safe throughout the project."

It's been a while since the country was hit by a hurricane, but in July 2008, Hurricane Dolly came ashore on nearby Padre Island with winds up to 100 mph.

"All this considered, one of the first challenges we had was how are we going to build the project safely-and that was where the majority of the planning and effort was directed," says Maag.

	At times, Mortenson crews came close-too close-to having to deal with hurricanes during the building of the Penascal II project. In a single day, they received more than five inches of rain in just two hours, as a result of a nearby hurricane.

The company put together a site-specific plan that took in the works, weather wise: consideration of blowing sand, extreme weather conditions, and emergency situations such as a hurricane. They also developed and executed a work schedule taking into account the weather.

"We established multiple work shifts and were often working from midnight right through to the next morning because the weather conditions were good for the workers, and for erecting the turbines. We had work going on pretty much around the clock on the project. But we were also able to perform work in the most logical sequence." The Penascal II project features 84 Mitsubishi 2.4 Megawatt turbines.

As any wind project contractor or developer knows very well, you can put a construction plan together for building a wind farm, but be ready to change it.

"You can plan these projects out, and we did," explains Maag, "but to a great extent, we had to be nimble and quick on our feet. We needed to understand, to the best of our abilities, what the weather patterns were doing and then revise our plan accordingly."

Essentially, they had a rolling work schedule that was very subject to change, almost entirely due to weather.

Maag noted that they came close-too close-to having to deal with hurricanes during the building of the project.

"We were carrying out construction right through the hurricane season," he says. "Fortunately, we did not actually experience a hurricane, but we had frequent heavy rains. One day, we got slightly more than five inches of rain in just two hours, as a result of a nearby hurricane. We often got slammed with all kinds of torrential rain."

The logistics of transporting all the various components of wind turbines 25 miles from the nearest highway, on a single roadway, was another challenge-even in building the access road. There was an existing road off the main highway, which they were able to upgrade. But the rest was a major project on its own.

Mortenson staggered the trucks so on certain days, in certain time windows, the road was dedicated to aggregate deliveries. "With the extreme heat, we placed a lot of the concrete in the evening and brought the placement crews in at midnight.

It wasn't quite as hot, the winds weren't quite as strong, and we were able to mix quality concrete on site."

As with all of their projects, Mortenson went to great effort to use local trades workers, and local suppliers. "In spite of the remote location, we were still able to buy a lot of materials from suppliers in the region, and in Texas, and use local people."

When the concrete delivery schedule ended, the road was then dedicated to turbine deliveries.

Maag noted that each wind power project brings its own unique challenges, and Penascal was no different, especially with its remote location. "It could be close to an hour of driving time from the time you turned off the highway to the time it would take to get to an actual turbine site."

	Penascal II is Mortenson's 84th wind farm project. The company expects to finish its 100th wind farm project late this year, or early in 2011.

In some coastal areas, bringing in material by barge might be an option. But there were sensitive

wetlands on the coast, near the Penascal site location. "We still would have had to build additional road if we brought material in by water," said Maag.

There were several wetlands on the project site itself, as well. From turbine locations to roadbuilding, the project layout was done to have no impact.

It's quite different from other wind projects, where the road might follow more of a grid pattern. "This road kind of snakes around the site," says Maag. "The road follows more of the wetlands-from the road to the turbines, the project flows very well with the natural environment in the area."

With large construction projects such as Penascal, and the large amount of land involved, progress can be a bit slower at times due to meeting the needs of multiple landowners. Mortenson and project owner Iberdrola Renewables were fortunate in that they only had to deal with one landowner-the John G. Kenedy Charitable Trust. "They were extremely good to work with, and very accommodating, so it really streamlined the entire construction process."

September/October 2010