,076-square-foot) patch on the California coast would equal the power production of a 6,400-square-meter (68,889-square-foot) solar panel array.
The ocean wave energy converter is meant to be set in 60 feet (18 meters) of water, where it's protected from storm damage by the water column above and would be largely invisible to those on shore. It must be carefully sited to avoid sensitive areas for marine life, like reefs, as well as recreational areas like surf breaks. But because the system greatly reduces wave impacts by absorbing their energy, it could also be strategically deployed to create "safe zones" near coastlines, protecting harbors or slowing erosion. "The idea first was producing power," Alam explained, "but when we presented it in conferences, the feedback I got was that protecting harbors was probably a more immediate application of this idea. Then you don't even need a pump, just the material to absorb the energy of the waves."
The carpet is currently undergoing wave tank tests and should move to open ocean trials by 2016, Alam said.
Buoys Boost Energy, Thwart Pirates, Perform Sea Surveillance
The buoys being installed for the large wave energy project off the coast of Victoria, Australia, might also be able to make the seas safer.
Ocean Power Technologies (OPT) PowerBuoys are anchored to the ocean floor but move freely up and down with the ocean swells, driving an onboard piston-like structure to power a generator and produce electricity sent to shore via subsea cable. They boast sensors that monitor their own performance and the ocean's movement, able to switch off power production when waves are too large and strong.
The buoys may avoid one challenge that offshore wind turbines have faced: At 38 feet (11.5 meters) high, the buoys present a far lower profile than offshore wind turbines, which can tower more than 440 feet (135 meters), and according to an OPT fact sheet, they are not highly visible at a distance of 3 miles (5 kilometers) from shore. Some offshore wind projects have sparked opposition because of their potential to disrupt ocean views. (Related: Cape Wind Deadline: Headwinds for Offshore Turbines.)
The buoys are anchored with a proprietary system to avoid seafloor ecosystem damage, and could even provide some benefits to marine animals by serving as an artificial reef, said Charles F. Dunleavy, chief executive officer of OPT.
In addition to delivering power to the grid, the buoys can power themselves at a remote location and support a flexible suite of sensors and equipment for maritime security and monitoring off the grid.
The U.S. Navy's Littoral Expeditionary Autonomous PowerBuoy (LEAP) program tested a smaller, totally autonomous version of the PowerBuoy with acoustic sensors, communications systems and signal processing. The equipment might be deployed someday as maritime surveillance, protecting sensitive areas or equipment and tracking illegal ship traffic.
Floating Pumps "Surf" on Wave Energy
Aquamarine Power's Oyster is a simple design, just as its makers intended, that basically functions as a wave-powered pump. The floating system features a large, hinged flap anchored in 33 to 50 feet (10 to 15 meters) of water in the near-shore zone, some .3 miles (.5 kilometers) out. The flap moves with wave motion, driving attached pistons that push high-pressure water through an underwater pipeline. That water is funneled to shore, where it powers a standard hydroelectric turbine—the design keeps complicated moving parts out of the ocean and on dry land where they can be more easily maintained.
The current Oyster 800 is has been at sea two and a half years—longer than any other mobile wave energy device. The device's location near the shoreline and its design are both aimed at mitigating one of wave power's top challenges-surviving the sometimes brutal conditions in locations like the Scottish coast.
"Survivability is one thing that we think differentiates Oyster, and it can really stay out there in big storms," said CEO Martin McAdam. "It's designed to spill excess wave energy over the top 