Although we've seen a number of experimental wave-power systems in recent years, a new one is claimed to be less expensive and to incorporate fewer moving parts, while still remaining durable in rough seas. It's known as a Dielectric Elastomer Generator, or DEG for short.
The prototype system was developed by scientists at Scotland's University of Edinburgh, and at Italy's Universities of Trento, Bologna and Scuola Superiore Sant'Anna Pisa. It basically consists of an anchored vertical cylinder which a column of air is trapped inside of. The top of the cylinder is sealed with a rubber membrane, while the bottom is open to the surrounding ocean.
As the crest of a wave passes around the device, it forces water up inside of the cylinder. This pushes the trapped air up, causing the membrane to expand. Once the device is in the trough of the wave, the water level inside the cylinder drops – this causes the membrane to be sucked down, as negative pressure is created inside the DEG.
Because the rubber incorporates layers of dielectric material, it generates voltage both as it puffs out and as it's pulled down. "The membrane is charged at its maximum inflation or deflation, it is discharged at the rest position," U Edinburgh's Prof. David Ingram tells us. "So energy is generated both from the wave crest and the wave trough passing the generator."
In a commercial version of the system (illustrated above), the resulting electricity could be relayed to shoreside communities via underwater cables. A small-scale prototype has already been successfully tested in a wave tank at the university – based on its performance, it is estimated that a full-size device could generate the equivalent of 500 kilowatts of electricity, which would be enough to power about 100 homes.
It is hoped that within a matter of decades, "fleets" of the DEGs could be deployed in areas such as the Scottish coastline, where powerful waves are plentiful.
A paper on the research was recently published in the journal Proceedings of the Royal Society A.
Source: University of Edinburgh
"(...)Engineers say that their design could be used in fleets of low-cost, easily maintained structures at sea within decades, to take advantage of powerful waves in Scottish waters.(...)"
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as i understand this .... the "within decades" is meant to express the durability of the structures
with me is the hope that in times where .... emission-free till 2030 ... is a goal worth to aim for, that in such times with great wishes of the people for effective change and also at the same time many a invention ready at this very moment to be upscaled and installed in massive dimensions .... that it surely will not need decades to replace toxic nuclear fisssion plants with such beautifull and elegant devices
Randy
I'll bet these things could be added to most seagoing ships to power lighting, accessories, etc.