Harnessing Renewable Energy
SU Alumni on the Cutting Edge
That’s the way he and his brother view extracting energy from the wind. Alfred Weisbrich first thought of the idea during the Arab oil embargo of 1973–74. He then was a presidential intern under Apollo 11 astronaut Michael Collins, the director of the Smithsonian Institution’s National Air and Space Museum. Alfred Weisbrich began thinking there had to be a better way to harness the wind than with large propellers. That belief solidified even further in the late 1980s and early 1990s when he worked with Kaman Aerospace for Sandia Laboratories, the U.S. Department of Energy/NASA and United Technologies in the development of wind turbines with expensive and complex blades measuring 250 feet in diameter.
He finally patented his invention in 1994. He knew that, despite their growing size, traditional turbines were only taking advantage of existing wind speeds to generate electricity. “To date, the whole industry has always concentrated on (increasing) the diameter of the blade,” says Gunther. “But we knew from the power equation that power is proportional to diameter squared and wind velocity cubed; in other words, that diameter is a squared function while the velocity of the wind is a cubic function. So we concentrated on what we could do to enhance the wind velocity, and that ultimately resulted in the WARP design. Once you amplify the wind flow, you can use all kinds of conventional recovery devices, of which propellers are still the best.”
So instead of using a single massive propeller blade (which today can exceed 400 feet in diameter), the concept incorporates numerous propellers of much smaller diameters—6, 10 or 20 feet. To turn the propellers, the Weisbrichs take a page from nature. Maximum wind speeds across a mountain occur along saddles, ridges, notches or in canyons, where the wind volume is concentrated as it whips through a narrow opening. It’s similar, says Gunther Weisbrich, to what occurs when you turn a corner amidst tall buildings on a windy day, or when you pinch a water hose.
Stacking any number of modules, hourglass-shaped like a woman’s body, the Weisbrichs mount the propellers in pairs on the “waists” of the modules, where the force of the wind is both amplified and smoothed out by the modules’ wider “hips.” The result: wind speeds amplified by 50 to 80 percent.
For example, if the ambient wind speed is 5 miles per hour, cubing that with traditional wind turbine technology would generate an energy factor of 125.
With a WARP tower, however, amplifying the 5 mph wind speed by 80 percent creates a 9 mph wind—cubed that’s an energy factor of 729, nearly a sixfold increase in energy generation. “Right off the bat, you can see how much more power you get from increasing the wind speed,” says Gunther Weisbrich. In addition, he notes that wind speeds are greater at higher altitudes. “We can build our systems very tall—300, 500, 800 or even a thousand feet tall,” he says. “That’s where the wind is, but conventional turbines can’t be built that tall.”
And because each module’s paired propeller turbines are mounted like lazy Susans and automatically face into the prevailing wind, they can take maximum advantage of prevailing winds, even as wind directions shift at different heights. Traditional large-blade turbines face in only one direction and require power to adjust to differing winds.
Finally, WARP towers require only about a quarter of the acreage of traditional large-blade wind turbines and can be built, according to the younger Weisbrich, for about $600 to $800 per kilowatt—less than half of the $1,500- to $1,700-per-kilowatt cost of large-bladed turbines.
Potential WARP towers can be built on land; atop buildings; atop already existing utility towers, which would both generate and transmit electricity; at sea, where wind velocities are greatest; both afloat and atop decommissioned oil rigs; and in rivers or at sea with modules both above and below the water. “The physics behind it allows this kind of technology to operate in any fluid flow, wind or water,” says Gunther Weisbrich. According to his brother, Alfred, WARP skin panels can incorporate photovoltaic solar cells to generate solar energy as well.
So far the concept has been proven in a wind tunnel test atop the Catskill Mountains and in Belgium and France, where two-module WARP towers are powering two industrial buildings.
Conventional turbines currently can generate a maximum 4.5 or 5 megawatts (each megawatt powers 700 homes). “We can build our systems to generate seven, 10 or 15 megawatts from just one tower, so why build a 300-foot-diameter blade when you can get the same energy from a bunch of 20-foot-diameter blades?” asks Gunther Weisbrich. “Our idea is to make large-bladed turbines obsolete. They are great engineering feats, but they are dinosaurs. We’re confident the timing is perfect. We just happen to have a better mousetrap.”
Among those interested in that better mousetrap is Ric Reaman. After reviewing the Weisbrichs’ Web site, he says, “I want to talk to Gunther. I like the compactness of their design and the increase in efficiency.”
He can envision WARP towers studding the ridges of Broad Mountain and Nesquehoning Mountain, propellers spinning madly while thousands of solar panels soak up the sun. It’s a vision for 21st century energy ushered in by Susquehanna alumni and produced on the remains of King Coal.
Bruce E. Beans is a contributing writer based in Philadelphia.