Anyone that has been tossed around by ocean waves can attest to their power. Unfortunately, scientists have had a hard time coming up with a way to harness this powerful source of free energy for commercial use. Now, some researchers from the University of California, Berkeley, may have a solution - seafloor carpets!
Assistant Professor Reza Alam, an expert in wave mechanics, thought of this brilliant idea after reading about how fishermen caught in storms in the Gulf of Mexico seek out areas where the ocean floor is known to be covered with a layer of thick mud. That's because the softer sub-surface absorbs a bulk of the energy, providing them protection from the large, violent waves.
Armed with this knowledge the professor and his team created a 'carpet' under which lie a slew of hydraulic actuators, cylinders, and pumps. The researchers envision that as the carpet gets tossed around by the waves, it will absorb their energy and transfer it to the cylinders that lie below. The energy collected can then be transported to shore and converted to usable power.
In laboratory tests conducted in wave tanks using a rubber carpet, the scientists were able to capture a stunning 90% of the energy released by the artificially created waves. This is a big improvement over solar panels which absorb only 10-20% of the sun's energy. To put it in perspective, just 150 square meters of the seafloor carpet would be capable of generating the equivalent of energy obtained from an entire soccer field (6,400 Sq.meters) covered with solar panels.
Since the mat would be on the sea floor, it would not impact boats or other human activity. Also, in order to ensure that there is no impact on marine life, the researchers are planning to place the seafloor carpets in near-shore 'dead zones' - areas with little oxygen and therefore no marine life.
While being able to harness the wave energy for everyday use is certainly exciting, what is even more so, is what Marcus Lehmann, a Ph.D. researcher working with Alam believes may also be possible using this system - powering desalination plants. The two methods - reverse osmosis and distillation currently used for desalination, require copious amounts of energy, which makes them too expensive for wide-scale use. A free source of power like the seafloor carpet located right next to a desalination plant would prove to be a game changer for our ever-increasing freshwater needs!
Professor Alam who first unveiled this exciting invention at the 10th European Wave and Tidal Energy Conference held in Denmark in September 2013, hopes to begin testing the system in the ocean within two years using a carpet made from a longer-lasting elastic composite material, which can withstand saltwater disintegration. If all goes well, the researchers hope to provide the world with an extremely cheap source of energy, within a decade.
Resources: newscenter.berkely.edu, gizmag.com