Two companies situated across the Atlantic have come up with interesting concepts of harnessing wind power at source, which will allow countries across the globe to exploit the largely untapped source of energy to meet their development needs.

The idea received a shot in the arm since it was revealed last year with commercial wind energy becoming competitive as against conventional grid energy sources. A study made by the Earth Policy Institute states that the cost of wind-generated electricity has fallen from 38 cents per kilowatt-hour in the early 1980s to 4 cents to 6 cents today, offering an almost endless supply of cheap energy. In addition, the technology also allays fears of depleting energy reserves or concerns over global warming.
US-based Stanbury Resources has last year introduced a concept of harnessing wind energy using the company’s innovative floating wind-hydrogen platform with battery storage, which will allow companies to harness wind energy by further lowering costs. The patent-pending model allows several three basic advantages over conventional land-based windmills.
First, the turbines are designed to install onto a floating platform, like an oil rig, so they can go to where the wind is -- further out to sea -- in contrast to present offshore wind turbines, which must be situated near the coast in waters shallow enough to build a platform onto the sea floor.
Lee refers to a “wind shadow” that extends from between a quarter of a mile to as much as a full mile out from the coast, dampening the strength of the wind as it comes ashore. “We can go far out beyond that, to where the wind is,” he said. “Offshore wind resources can be vastly more power productive than onshore winds, particularly if not influenced or affected by large land masses”.
Second, the company has a proprietary method of tapping the wind turbine energy to convert seawater efficiently into hydrogen, with a byproduct of pure oxygen.
Third, rather than the wind energy being conveyed directly into the grid, it is stored in a battery system so that it is available continuously and can be used as a primary grid energy system.
Although the batteries do make the system more expensive than other wind systems, it can function as a primary energy system, rather than just supplemental and provide a continuous flow of energy.
Even more importantly, such a system has the advantage of being able to supply the energy in response to the grid needs, by responding to energy peaks and troughs, rather than having to ramp up to peak load and then waste everything else, which is the case with nuclear power, and to a lesser extent with coal, natural gas, and hydro grid power stations.
Though hydrogen burns cleanly, typically its production is tied to polluting processes, and is accompanied by a net energy loss, requiring more fuel to create than it gives off. Lee claims his system produces hydrogen cleanly, using wind energy.
“The system does not go straight from the turbines to electrolysis, but involves batteries. Though proprietary, Lee’ says his new hydrogen system has solved the net energy deficit dilemma.”
However, not all platforms would involve hydrogen production. The platforms on which hydrogen production would take place would need to be quite a bit larger to house the pressurised hydrogen tanks. Hauling systems similar to those used in the transport of oil would then ship hydrogen to ports, where it would be offloaded onto tanker trucks and trains.
According to Lee, the floating platforms – held upright by an underwater keel, along with some dynamic ballast controls and a four-direction propulsion pod system – would cause minimal disruption to the sea floor below, requiring just a modified anchor to keep them moored in place.
Low transmission electrical cables would then hook the platform to the mainland. Lee says that distances of even 1,000 miles would not be a problem for the platform, to situate it well, and then transmit the electricity to its destination.
Though fitted for occupancy, the platform would be navigable by remote control, with continuous GPS position reporting.
The platforms are capable of navigating at speeds of up to 20 knots, which means they could be steered out of trouble in case of a storm. “An onboard cable reeling system could accommodate movements of up to three miles without requiring detachment. If the electrical cables need to be detached, they would be held in place by a buoy, until the platform returns,” says Lee.
Hywind
Elsewhere across the Atlantic, Hydro, a Norwegian company, has come up with a radically different model of harnessing wind power at sea. Called the Hywind, the floating concrete construction technology developed for the North Sea oil industry can be applied to offshore windmills.
“Hywind is a future-oriented project combining our offshore oil industry experiences with our knowledge of wind power to take advantage of wind resources where it blows most – at sea. If we succeed, this can become an important part of our future energy supply,” says Hydro’s director of new energy forms, Alexandra Bech Gjorv. Hydro is using the ocean basin in Trondheim to simulate wind and wave conditions at sea. A model of the floating windmill has been tested and the results are promising.
“We are now evaluating the placement of a windmill in the North Sea to demonstrate that it is possible to build offshore wind parks at sea depths of 200 to 300 m,” says Bech Gjorv.
Hydro has measured wind speeds in the North Sea for more than 30 years. Based on data determining that average wind speeds at sea are higher than on land, Hywind will be exceptionally energy efficient. Gjorv emphasises that Hywind will be a supplement, not a substitute, to land-based wind parks.
“Hywind is very well-suited for energy poor areas where there is little accessible land, but good offshore wind conditions, for example in the US, Japan and in the vicinity of offshore installations,” she says.
A demonstration project is currently being planned based on wind turbines with a power generation capacity of 3 mega watt (MW). The windmills will reach 80 m above the sea’s surface and will have a rotor diameter of about 90 m. According to plans, the demonstration project will start operating in 2007. “We eventually envision wind turbines with a power capacity of 5 MW and a rotor diameter of approximately 120 m,” says Bech Gjorv.
“The future goal is to have large-scale offshore wind parks with up to 200 turbines capable of producing up to 4 terawatt hours (TWh) per year and delivering renewable electricity to both offshore and onshore activities. This goal is far in the future, but if we’re to succeed in 10 to 15 years, we have to start the work today,” Gjorv concludes.