TechPulse 360

Joby Energy says it plans to launch its first airborne wind turbine off the California coast this year in a trial that could make or shatter dreams of power stations in the sky.

The company was vague about details of the test during a presentation late Thursday. But it said its goal is to fly a tethered rectangular kite-like device with eight blades about 2,000 feet above Santa Cruz before the end of the year.

Joby founder JoeBen Bevirt and a picture of his proposed ariborne wind turbine

“We are in the final stages of planning,” Joby founder JoeBen Bevirt said during a Silicon Valley appearance.

The 30 kW, 180-pound turbine is a precursor to 10 MW and 20 MW machines Bevirt hopes to eventually send aloft. He says he conceived of piping the electricity down tether cables and into the electrical grid for 3 to 4 cents a kWh. Ground based turbines can be 5 cents or more.

Bevirt’s flying turbine is by no means the first to be designed for use in the atmosphere. Development has gone on in Holland, Italy and elsewhere in the United States, but little commercialization has followed.

Nevertheless, the potential is high. While wind is inconsistent and intermittent on the ground, it is steadier and often non-stop in the atmosphere. By some measures, winds aloft have 10 times the energy of sun light, with the highest concentrations in the jet stream. However, flying kites and turbines that high creates navigation hazards for aircraft.

Bevirt initially hoped to fly in the jet stream, but was dissuaded by the Federal Aviation Administration, which said it would take years to secure permission. His fall back position is below 2,000 feet, where navigational hazard is less.

While engineers have conceived of sending turbines aloft for decades, only recently have materials become light and strong enough to make the technology viable. Tethers, for instance, can be made of Kevlar, and blades can be designed smaller and still capable of spinning faster than those of ground-based turbines.

Bevirt says he built his kites in 40-foot modular sections. The assembled modules for a 5 MW kite would measure 240 feet in length. Yet, the “control system is really the heart of the challenge,” he says. “We’ve put most of our time into this.”

Now after months of design, he says, Joby is ready.

This entry was posted on Friday, April 16th, 2010 at 11:23 am and is filed under news. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.