See power- Capt. Greg Aurre did, and he has patents on his efforts to draw energy from the sea

September 24, 2008 at 3:39 pm Leave a comment

Sitting on the bridge during night watch, Capt. Greg Aurre noticed how the tide piled water up against a buoy, pushing it over 45 degrees. Like many yacht crew who spend hours on watch, he wondered how to harness that tremendous power, and even came up with an idea or two.

Unlike many yacht crew, however, Aurre has put his ideas to paper and gotten patents on a water turbine generator that just might influence how Americans get their power in the future.

Aurre spent five years in the oil industry running tugs, barges, crew boats and utility boats around New York and in the Gulf of Mexico. In 1997, he entered the yachting industry, running a 114-foot charter sailboat in the Med and Caribbean, and powerboats along the U.S. East Coast.

Throughout his time at sea he watched the tides through Hell Gate on New York’s East River and the waters around Florida with the steady Gulf Stream, realizing there had to be a way to harness that power.

Turning his night-watch visions into reality started over Thanksgiving dinner last year when Aurre and his family tossed about ideas of alternate forms of income. Although his family was skeptical of his water turbine idea, he was confident it could work, so he started Coastal Power, an alternative energy company based in South Florida.

Historically hydro-electric power has been generated by dams with turbines, which require large amounts of vertical water pressure created by “head” to generate power. Aurre’s method differs in that it will use horizontal, natural water pressure at lower speeds, namely tides or other currents.

To make a turbine function, however, the water flow must be sped up to at least 5 knots. To do that, Aurre considered the Venturi effect, as is used in gasoline carburetors. Using the same theory to funnel water from an 8-foot opening to a 2-foot pipe, Aurre hopes that will maximize water pressure for his power generator. Laid horizontally, the nozzle allows for tidal flow to pass the prop both ways, generating power on both the ebb and flood tides.

He’s also considering the Bernoulli theory, a modification of the Venturi effect. It works on the same principle, Aurre said, but instead of being a straight-sided nozzle, it is shaped similar to an automobile transmission bell housing with the water being compressed in stages. (See sketch I).

Both the Venturi and the Bernoulli nozzle shapes will be tested in prototypes that are being constructed this fall.

Aurre figured that the water pressure could be further increased by placing a propeller inside a tube, much like a bow thruster. And he added a “jet pack,” which accentuates the speed of the water yet again by forcing it from the 2-foot nozzle through four jets, each 6 inches in diameter, before being shot onto the propeller.

Although Aurre has developed this project in the initial stages, he brought a few team members onboard when he started Coastal Power in April. His son, Gregory Aurre III, has a business background, and Matthew Albright was recruited as the consulting engineer. Albright is still working out the viability of Aurre’s sketches.

“It is most likely the jet pack will be incorporated into at least one prototype,” Aurre said.

With the addition of the Venturi or Bernoulli intake nozzle, the enclosed prop and the jet pack, Aurre is confident the speed will be picked up in excess of 5 knots, which will force the prop to turn at a rate sufficient to generate power.

His next challenge was to find the perfect propeller for his generator. While conducting engine room checks, Aurre found himself staring at the engine room fans, amazed at the amount of air they moved.

He compared them to his own sailboat’s wind generator blades, and realized they operated with reverse theories.

“The engine room fan blades are shaped to push air, whereas the wind generator blades are designed to be pushed by air, thus generating power,” Aurre said. He has modified the wind generator prop to be more adapted to moving water, and it has become one of the design options in his patents.

Recognizing the proven validity of a traditional turbine impeller, Aurre will also be including a slightly modified version as a prototype possibility as well. Not totally convinced that’s the answer, however, he went back to the basics of boating and remembered how simple and relatively flawless the old knot-meter paddle wheels were.

What if he laid it on its side? In this fashion, the gear-shaped wheel is not only used as a propeller, being moved by the water pressure, but the shaft holding the wheel extends upward to become the shaft generating power. Although this style of impeller may not be as efficient as a turbine prop, Aurre said it eliminates the need for a gear box, and thanks to its simplicity it may be a good option.

The final option is a straight drive shaft to an underwater generator in a watertight cofferdam. But the unit becomes one-directional, making it necessary to have two units at each location, one for ebb and another for flood, Aurre said.

“I’ve tried to keep costs down to make sure the units will pay for themselves within three years but I think this unit, even with its added costs, may produce enough power that it will still pay for itself quickly,” Aurre said.

Actual wattage produced by Aurre’s three prototypes can only be determined by trying them. Still, Albright has calculated some estimates.

“They are thought to be able to produce between 25 and 100 megawatt hours (mwh) on a monthly basis,” he said. “This is enough to power approximately 27-109 average U.S. households.” The U.S. Department of Energy estimates the average residential household consumes 920 kwh per month.

How does this compare to other energy sources?

According to Renew, a typical commercial 1.5 megawatt wind turbine at the Montford Wind Farm “generates approximately 217 mwh monthly, enough to power 236 households.”

Alternately, a typical residential solar power installation in California on a large home will produce .333 mwh monthly, less than a third of the electricity an average household needs,” Albright said.

“Ours are the most technologically advanced water turbines in the world,” Aurre said.

Although other turbines have attempted to harness hydro-kinetic energy in New York, they haven’t succeeded. In 2006/2007, a company called Verdant Power installed a turbine off Roosevelt Island. The waters were more powerful than anticipated, though, as reported in “About New York” in August 2008.

Companies in Massachusetts and Texas are also getting onboard with plans to test turbines, but none had applied for permission to sell power to the national grid as of press time, according to Aurre.

Aurre plans to test his three prototypes in 2009, monitoring their output closely to establish which is most efficient. By building the turbines using marine-grade materials, Aurre and Albright are confident they can produce power sooner.

“We’ve seen many hydrokinetic companies tank test modified wind turbine technology, only to see their models fail in the real world,” Albright said. “Our focus is on generating revenue for our shareholders as soon as possible, not winning awards in tanks.”

Aurre and Albright maintain that it will take less than three years to pay off the cost of building and installing the turbines, an exceptional goal according to Gary McCarthy of Calypso Electronics, who sells and installs energy-generating systems.

“Most people aim at recouping their initial outlay within 10 years,” McCarthy said. At the same time, though, McCarthy said he’d be interested in hearing about Coastal Power’s final wattage outcomes.

If the prototypes prove what Aurre thinks they will, he plans to build six turbines for installation along the East River, and Coastal Power will be ready to begin selling power to the national grid.

Although there is a seemingly unending list of government approvals to be obtained, much of the paperwork for this mega project is already in place. Ten patents have been applied for, with approval received for two.

Aurre has received a letter from the Federal Energy Regulatory Commission (FERC) confirming his application to locate the generators in six specific locations in Hell Gate. Coastal Power is also approaching the office for permission to sell hydro-kinetic energy to the national grid.

“We don’t anticipate any problems with the permits,” Aurre said, predicting all government approvals to test the prototypes will be issued by early next year.

“Government support has been overwhelming for this project,” he said, “especially from FERC. They offered me assistance in completing the paperwork, and have even offered me the use of office space.”

A FERC press release on April 14 noted its interest in “exploring ways to reduce the regulatory barriers to realize the amazing potential of this domestic renewable power source.”

If the turbines work in the East River, Aurre said Coastal Power plans to test a tower of turbines in the Bay of Fundy and then install even larger towers in the Gulf Stream off the Florida coast.

In less than a year Aurre has taken his night-watch visions from fleeting thoughts to patented ideas, government approvals, and prototypes designs. Within 16 months of conception he plans to have working turbines actually generating power.

See what can come out of a night watch?
Mate/Chef Marianne Gardner has worked on megayachts since 2001 and runs her Corbin 39 Dolphin Spirit with her partner, Capt. Mike McKee
The Triton Megayacht News


Entry filed under: Dive In, Public Waterfront. Tags: , , , .


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