Anyone who has ever played in the surf knows the crushing power of waves, and many have schemed of ways to harness that energy and convert it into electricity. Thomas Edison and Alexander Graham Bell both toyed with the notion.
Today, however, dozens of companies with various technological approaches are attempting to tap ocean power. Since ocean currents and wave power qualify under the recently passed renewable energy bill, there is no telling what role ocean power will play in our energy future.
Ocean Power Technologies (OPT), a small company near Princeton, N.J., may have solved the problem that could open the oceans for new sources of unlimited renewable energy. It is a simple idea that the company has been proving practical at installations in Atlantic City, N.J., and Hawaii. Now it appears the technology is going utility-size on the West Coast and in the United Kingdom.
It’s basically a large “smart” buoy that is anchored offshore. Like an iceberg, most of it floats below the surface, so there’s minimal visual impact. OPT calls it the PowerBuoy. It is designed to capture and convert wave energy into low-cost, clean electricity. The rising and falling of waves moves the buoy up and down. Inside the buoy, a power take-off system generates AC, sending electricity down the power cable and over the seabed line to a utility. Sensors on the buoys continuously monitor subsystems and the ocean environment. Real-time data is sent to shore. In the event of very large waves, the system automatically stops power production. When wave heights return to normal, it unlocks and recommences energy conversion and transmission.
The current PowerBuoy is rated at 40 kilowatts (kW). However, a new 150-kW commercial version is being deployed. Ocean trials began in 1997 with one buoy off the coast of Atlantic City. It proved successful, and PowerBuoys continue to operate there for the New Jersey Board of Public Utilities. Since 2001, OPT has been deploying PowerBuoys for the U.S. Navy at a Marine Corps base in Oahu, Hawaii, with the objective of demonstrating wave power for Navy bases worldwide. OPT recently was awarded a contract for a demonstration project in Scotland.
In late January, defense contractor Lockheed Martin announced an agreement with OPT to develop utility-scale generation projects to capture wave power off the coasts of California or Oregon. OPT will provide its PowerBuoy technology, and Lockheed Martin will provide the construction, systems integration, deployment of the plant, operations and maintenance. The Federal Energy Regulatory Commission has issued preliminary permits for four PowerBuoy sites on the Pacific coast.