Northwest Energy Innovations, LLC has developed the Azura™ wave power generation technology for converting the endless supply of ocean waves into electricity to meet the rapidly growing global demand for renewable energy.
Unlike other wave energy technologies, Azura extracts energy from both the heave (vertical) and surge (horizontal) motion of the wave, producing power from the relative rotational motion between the hull and float. The power takeoff (PTO) system is based on high pressure hydraulics and is located within the PowerPod.
A key feature of the Azura design is that the float can rotate continuously through 360° or oscillate back and forth, which enables the device to extract energy in a wide variety of wave conditions and improves the overall efficiency of the system. The fully rotating float also provides a self-limiting power shedding effect, which makes the device inherently survivable in open ocean environments and helps to reduce loads in the mooring system. Another benefit of the Azura design is the very low reserve buoyancy, which allows it to partially submerge under large waves.
The initial technology development, called Wave Energy Technology New Zealand or WET-NZ, was conducted by Callaghan Innovation (formerly Industrial Research Limited), which is a New Zealand Crown Entity. Since development began in 2006, the technology has advanced from initial concept to open ocean pilot testing. Recognizing the potential of the US market, NWEI began collaborating with Callaghan to further develop and optimize the technology.
Since commencing operations in 2010, NWEI and its partners have successfully completed pilot scale projects in New Zealand and Oregon, and NWEI is now, with support from the Energy Department and the U.S. Navy, open-sea pilot testing. The device was recently launched and installed in a 30-meter test berth at the Navy's Wave Energy Test Site (WETS) in Kaneohe Bay, on the island of Oahu, Hawaii. This pilot testing is now giving U.S. researchers the opportunity to monitor and evaluate the long-term performance of the nation's first grid-connected wave energy converter (WEC) device to be independently tested by a third party—the University of Hawaii—in the open ocean.
The project supports the Energy Department's mission to research, test, and develop innovative technologies capable of generating renewable, environmentally responsible, and cost-effective electricity from clean energy resources, including water. Marine and hydrokinetic (MHK) technologies, which generate power from waves, tides, or currents, are at an early but promising stage of development. Many coastal areas in the United States have strong wave and tidal resources, and more than 50 percent of the U.S. population lives within 50 miles of a coastline, making transmission from these resources more economical. With further progress towards commercialization, MHK technologies could make substantial contributions to the nation's electricity needs. To accelerate commercialization of wave energy devices, the Energy Department funds research and development—from laboratory and field-testing of individual components, up to demonstration and deployment of complete utility-scale systems.
To further advance Azura towards commercialization, NWEI recently launched its grid-connected 20-kilowatt demonstration project at WETS. The current phase of in-water testing at the WETS's 30-meter test berth has already proven valuable in gathering performance and reliability data from the device in deepwater, open-ocean conditions. The data will be used to further optimize Azura's performance and refine existing wave energy computer simulations, ultimately supporting commercialization of this technology.
NWEI, with $5 million in additional funding from the Energy Department, will apply lessons learned from this current phase of development to modify the device design in order to improve its efficiency and reliability. NWEI plans to then test the improved design with a full-scale device rated between 500 kilowatts and one megawatt at WETS at even deeper test berths of 60 meters to 80 meters over the next several years.
Sources: US Department of Energy and Northwest Energy Innovations
Top image: Northwest Energy Innovations