Wind turbines continue to draw interest as a promising renewable energy source. Engineers are still addressing challenges, nonetheless, over how to ensure wind power becomes a more viable energy source making economic as well as technical sense. According to the Iowa Energy Center, which is administered through Iowa State University, explorations into designs include augmentors; some experimental turbines have incorporated this added structural feature intended to increase the amount of wind passing through the blades. Meantime, engineers continue to imagine and work on more efficient designs that put out a greater amount of power at a justifiable cost. Alternative energy sources like wind power provide new options and certain advantages, said the Center, but to be truly competitive with conventional energy sources, they also must be economical.