New wave power development offers promise of cheap, green energy

by Jay McDonough

Using the tremendous power of the oceans, either in the form of wave motion or temperature gradients, is touted as an exciting new prospect in the search for new, green alternative energy sources. 

There are a couple constraints, however, with conventional wave motion in the number of locales they can be installed and that the turbines and water mills need an average current of five or six knots to operate efficiently.  Most of the worlds waterways flow slower than three knots. 

A system recently developed at the University of Michigan promises to convert even these slower flowing waterways into usable electrical energy.  The system, called Vivace (vortex-induced vibrations for aquatic clean energy) can be placed on riverbeds or suspended in the ocean and, potentially, offers competively priced alternative energy.

The new device, which has been inspired by the way fish swim, consists of a system of cylinders positioned horizontal to the water flow and attached to springs. As water flows past, the cylinder creates vortices, which push and pull the cylinder up and down. The mechanical energy in the vibrations is then converted into electricity.

Cylinders arranged over a cubic metre of the sea or river bed in a flow of three knots can produce 51 watts. This is more efficient than similar-sized turbines or wave generators, and the amount of power produced can increase sharply if the flow is faster or if more cylinders are added.

The scientists behind the technology, which has been developed in research funded by the US government, say that generating power in this way would potentially cost only around 3.5p per kilowatt hour, compared to about 4.5p for wind energy and between 10p and 31p for solar power. They say the technology would require up to 50 times less ocean acreage than wave power generation.

"If we could harness 0.1 per cent of the energy in the ocean, we could support the energy needs of 15 billion people. In the English Channel, for example, there is a very strong current, so you produce a lot of power."  (Link)

Clearly, there's great work being done in the development of alternative energy sources.  One of the big obstacles to implementing these alternative energy sources will be the development of a transmission grid capable of transporting the electrical energy developed deep in the Pacific Ocean or from the windswept prairie states to far away locales.  This is where Barack Obama's infrastructure stimulus proposals come into play: It's the opportunity to employ Americans, develop green and non-imported energy, develop world class intellectual property, and position the U.S. for the next century.

Comments

[sherry]

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