Ocean Swell Wind Generator

SUBHEAD: Using the physics of the blowhole to generate electricity for Hawaii in the ocean.  

By Henry Curtis on 14 January 2011 in Disappeared News -  

Image above: Oceanlinx swell driven generator prototype at Port Kembla, near Sidney, Australia. From (http://www.mywindpowersystem.com/2009/09/ocean-wave-energy-alternative-energy-part-7/).

Some wave systems operate underwater. Others wiggle on the surface. Some use toxic substances. Many have broken down in the water. Get all of that out of your mind. Let us talk blowhole energy. A traditional blowhole is a cave along the ocean with a hole in its roof. When a wave reaches the shore its fills the cave with water and a water column is shot out of the hole. This is, in non-legalese, a land-based water-shooting blowhole.

By contrast, if the cave does not fill with water, an air column can shoot out of the hole. This could be called a land-based air-shooting blowhole. Offshore ocean-based platforms have similar phenomena. Picture any partially submerged container with the open end facing the oncoming waves. It could be a paper bag, a box, a container. As a swell arrives the water level in the container rises, as the swell recedes the water level falls.

Picture a small hole in the roof of the container, at the end away from the incoming swell. With each swell an air or water column is pushed out and then sucked back into the hole in the roof. A propeller is placed just above the opening.

As the air or water races by the propeller the propeller spins creating electricity. These could be called ocean-based air-shooting blowholes and ocean-based water-shooting blowholes. An Australian mathematician figured out how to spin the propeller in the same direction regardless of which way the air column is moving (in or out). This increases the efficiency of the unit. This is also simple.

The center of the propeller is solid and there are small spokes or toggles on the side. They move as wind hits them. So the center always spins in the same direction and the paddles on the edge move back and forth to allow wind pushing on them to pass by. A fancy name for a variable height water column is an oscillating water column.

An oscillating water column energy conversion system has only a single moving part. For air-shooting blowholes the moving part is above the water line. For water-shooting blowholes the moving part is sometimes above the water line. There are no oils, no toxics, and no contaminants. The system has been commercially tested off Australia, and will be built off Maui.

The Maui system will be a single small unit since the utility can accept small but not large proposals outside of the new Public Utilities Commission approved competitive bidding process. Dr. Tom Denniss and his company Oceanlinx (formerly Energetech) has won numerous awards. It was a Top Ten finisher in 2006 for the International Academy of Science's Outstanding Technology of the Year. European Venture Capitalists has found that it is the most cost effective wave energy system in the world.

The Electric Power Research Institute (EPRI) found that Oahu-based wave energy conversion systems could provide 100% of Oahu’s energy needs. The blowhole energy systems can produce net power (after accounting for the power to run the system) with a six inch ocean swell. The physical structure rises about 30 feet above sea level. Each unit can produce 2MW of power. A field of several units located 3 miles off the coast could be tied to the grid with a single undersea transmission line.

The use of horizontal directional drilling would allow the line to be built below the beach and coral reefs, and then to rest on the bottom of the ocean the rest of the way to the wave energy system. The system can be built in Hawaii rather than imported, thus increasing the number of local jobs. The location of the proposed unit is about half a mile offshore from and east of Pauwela Point Lighthouse.

The transmission line would come ashore at Kuiaha Bay (Shark Bay). See also: http://spectrum.ieee.org/energy/renewables/this-renewable-energy-source-is-swell http://www.science.org.au/events/publiclectures/re/denniss.html

[IB Publisher's note: The illustration above was in an article on wave energy that described some advantages and disadvantages of floating wind generators moved by ocean swell.
Advantages • The energy is free – no fuel is needed and no waste is produced • Inexpensive to operate and maintain • Can produce a significant amount of energy.
Disadvantages • Depends on the waves – variable energy supply • Reeds a suitable site, where waves are consistently strong • Some designs generate noise • Must be able to withstand very rough weather • Costly to develop • Visual impact if above water or on shore • Can disturb or disrupt marine life – including changes in the distribution and types of marine life near the shore • Poses a possible threat to navigation from collisions due to the low profile of the wave energy devices above the water, making them undetectable either by direct sighting or by radar • May interfere with mooring and anchorage lines with commercial and sport-fishing • May degrade scenic ocean front views from wave energy devices located near or on the shore, and from onshore overhead electric transmission lines.] .

1 comment :

Anonymous said...

Nice concept but, oh dear, wait until a big NPac swell hits and it gets ripped off its moorings! Technology triumphalism? When will we learn?

Post a Comment