GEORGETOWN -- In the still and humid morning air Wednesday, researchers on a platform at the mouth of Winyah Bay hoisted the meteorological equivalent of a boom box, a new device that measures wind speeds using sound.

If successful, the novel wind monitor could dramatically reduce up-front costs for new offshore wind farms, said Ralph Nichols, an engineer with the Savannah River National Lab.

Data collected by the device also could help pinpoint a place off South Carolina where winds are strong enough to turn generator blades the size of a commercial jet.

The installation of the sonic wind device -- the first test of its kind off a North American coast -- is part of a larger state and federal effort to build wind farms and manufacturing facilities off the East Coast.

A consortium led by Santee Cooper is exploring the feasibility of installing 40 turbines off the Carolina coast. Meanwhile, Clemson University's Restoration Institute will break ground this fall on a $100 million turbine test lab at the old Charleston Navy base.

"All of the work that we've done in the past year is geared to reducing the cost of energy (from wind)," said Nicholas Rigas, the institute's renewable energy director.

In some areas of the country, land-based wind generators already produce electricity at costs comparable to coal, nuclear and other traditional sources that burn fossil fuels.

But energy experts say that offshore winds, which blow harder and more reliably, could be an important addition to the nation's renewable energy portfolio, particularly on the East Coast.

Winds off South Carolina could generate 3.5 gigawatts of power, according to the Savannah River National Lab. That's equivalent to six large coal plants or enough electricity to power 1.75 million homes.

As with many large capital projects, up-front costs can be a big hurdle, and that's why this week's project in Winyah Bay is so important, Nichols said.

With thunderclouds building in the distance, crews on Wednesday fastened planks to a wooden platform belonging to the U.S. Coast Guard. "We're ready!" a worker yelled to Nichols, as workers secured straps to the SODAR device, short for "sound detection and ranging."

Built by a company called Second Wind, the SODAR device costs about $50,000 and weighs 500 pounds, Nichols said. From a distance, it looked vaguely like something not particularly technical.

"A guy came by and said the government was putting in a portable toilet for (boaters) who can't make it in on time," Nichols joked.

Inside the device, however, are sophisticated electronic machines that shoot high-frequency chirps into the air.

The chirps are barely audible, he said, but sensitive noise detectors can use these sound signals to measure winds 600 feet above.

Scientists need measurements at that level because winds are generally stronger at higher altitudes and modern wind turbines now stand 300 feet high or taller.

Scientists will monitor the sound device's data for a year and test its accuracy, Nichols said. If successful, the device could replace traditional anemometers, which require costly tall towers to install.

Nichols said a typical anemometer, tower and platform might cost $4 million, while the $50,000 SODAR requires a simple platform without a tower. Savings would be in the millions of dollars, he said. The technology has been tested in the North Sea but not at the 600-foot heights that this device can measure. "No one is measuring the altitudes we are," he said.

"A lot of people worldwide will be interested in this," Rigas added. "It could allow you to rapidly assess an area at a lower cost. And if you reduce the cost of exploration, you're reducing the investment and the cost of energy delivered."

Santee Cooper is learning how much those up-front costs can set you back. A year ago, Santee Cooper and Coastal Carolina stationed buoys off Little River and Winyah Bay to gather wind data. That project will cost about $410,000, said Mollie Gore, the utility's public relations director. The utility is likely to shell out another $4 million to build an anemometer tower.

The SODAR technology is still new, so financiers interested in bankrolling a wind farm probably will require data from anemometers, at least in the near term, Nichols said. He said that data from Santee Cooper's buoy arrays so far have confirmed that offshore winds are strong enough. "The results are a little better than we expected," he said Wednesday as crews worked on the device.

The wind was notably still that morning, with the water so flat in places that pelicans could glide 2 inches above the surface.

But by mid-day Wednesday, the SODAR was chirping and collecting wind data, and the stillness gave way to the freshening breeze we typically see during summertime.

Within four hours, wind speeds were 18 mph roughly 100 feet above the surface, Nichols said. That's enough wind to generate about one to 2 megawatts from a single offshore wind turbine, electricity that could power 500 to 1,000 homes.

Reach Tony Bartelme at 937-5554 or tbartelme@postandcourier.com.