Steady winds blow in fuel savings

  • Published
  • By Tommy Baker
  • 611th Civil Engineer Squadron
ELMENDORF AIR FORCE BASE, Alaska --  Saddled with the rising price of diesel fuel, remote location and bone-chilling winter temperatures, Tin City Long Range Radar Station's operating costs are extraordinarily high. In an effort to reduce operating costs, the 611th Civil Engineer Squadron was recently awarded $1.9 million through the Energy Conservation Investment Program, a Department of Defense military construction initiative. The ECIP is specifically designed for projects that save energy or reduce defense energy costs. Engineers with the 611th CES have completed the construction of the first wind turbine generator to be installed at an Alaskan air base and within Pacific Air Forces. The wind turbine generator will augment the power production system at Tin City, making it a wind-diesel hybrid. 

"I'm very excited about the Tin City wind turbine energy project. This important milestone for the 611th Air Support Group will be the first renewable Air Force energy project in Alaska and is very timely, given the cost of fuel. Wind energy at Tin City should decrease our annual fuel consumption by 30 to 35 percent, about 85,000 gallons," said Col. Brent Johnson, 611th ASG commander. 

Tin City LRRS is currently powered by diesel generators. It is located on the westernmost point of the North American mainland, Cape Prince of Wales, on the western tip of the Seward Peninsula in the Bering Sea, approximately 700 miles northwest of Anchorage and approximately 600 miles west of Fairbanks. On a clear day, you can see all the way to Russia from this northern outpost of the United States. 

The prevailing winds on the western coast of Alaska put the area in a class seven wind power density zone, the highest possible category. Wind power density is a useful way to evaluate the wind resource available at a site. The WPD indicates how much energy is available at the site for conversion by a wind turbine.   

After extensive wind strength and reliability testing, it was determined that Tin City would be the ideal candidate for a single tower to test the real-world application of wind generation at remote radar stations. During the testing, sustained wind gusts of 83 miles per hour, which is equivalent to a Category 1 hurricane, were experienced. However, according to 611th CES engineers, the average wind speed at Tin City is about 19 miles per hour. 

"That's separate from the maximum sustained wind speed experienced, which was 83 miles per hour. Not saying it's 83 miles per hour often, but it illustrates the extreme conditions at the site," said Tony Alecci, 611th CES energy management chief. 

A potential annual energy savings of $433,000 is estimated.  The currently installed digital control system, to accompany the tower, allows for more precise control of the existing diesel generators. This allows the site operators to completely shut down the diesel generators when the wind strength is sufficient to power the site. It allows for tailoring the diesel power production to complement the wind production, thus minimizing the fuel usage at the site. The resulting reduction in diesel generator run time is estimated to save $10,000 annually in reduced maintenance costs. 

In order to harness the available wind, there were a number of challenges. The first was the tremendous icing that the costal sites experience, with Tin City being the worst.
The construction and installation contractor, Tanadgusix Corporation, an Alaskan native corporation, has extensive experience with cold weather wind generation from their St. Paul Island, Alaska, wind turbines. Together with the engineers from the 611th CES, a cutting-edge cold weather package was developed to meet the unique needs of such a harsh environment. 

The foundation of the package is an electric based heat system that blows warm air up the tower base and through the tips of the turbine blades to shed the expected icing load. When combined with passive solar blade heating and low temperature lubrication of the nacelle, the most robust cold weather package known for wind turbines is achieved. 

In addition to icing issues, airfield safety, radar interference and migratory bird strike issues needed to be addressed. Through working with the FAA and the use of Avian studies, potential tower locations were identified that would provide for negligible impacts on any of the three challenges. 

"The 611th Air Support Group is working smarter. With the installation of the wind turbine at Tin City, we are using proven, commercial, off-the-shelf technology. Similar turbine units are in use at Nikolski, Sand Point and St. Paul Island, Alaska. Wind turbines are not new to the U.S. Air Force, but they are new to Pacific Air Forces and 11th Air Force in Alaska," said Lt. Col. Charles Busch, former 611th Civil Engineer Squadron commander.
With the reduction in fuel consumption, Colonel Busch said the return on investment should be realized within about four and a half years. 

"We have several other wind turbine projects scheduled. The 611th CES is currently pursuing wind turbines at Cape Lisburne, Cape Romonzof and Cape Newenham.  Engineering work is also taking place to judge the suitability of wind power generation at Eareckson Air Station," said Colonel Busch. 

By presidential order, federal agencies must improve energy efficiency and reduce greenhouse gas emissions by three percent annually through the end of fiscal year 2015, and, to the extent feasible, implement renewable energy generation projects on agency property for agency use.

"The 611th continues to work aggressively toward meeting the Presidential Energy goals," said Colonel Busch.