Azura (wave power device)

Lore & Background

Azura was initially developed under the name WET-NZ by Callaghan Innovation in 2006. The concept progressed through stages: TRL 1 (initial concept), TRL 3 (micro-modeling), and TRL 5/6 (large-scale prototype tested near Christchurch, New Zealand). The device floats on the surface, weighs 45 tons, and uses a unique 360-degree rotating mechanism to capture energy from both horizontal (surge) and vertical (heave) wave motion. It is a point absorber, the most common type of deepwater wave energy generator, and uses a high-pressure hydraulics system driven by crankshafts.

A smaller prototype was first tested in a wave tank, followed by a second prototype installed for six weeks in 2012 at the Northwest National Marine Renewable Energy Center’s test site off Oregon, where it endured waves up to 3.75 meters. A later version was tested at the Marine Corps Base Hawaii Wave Energy Test Site on Oahu from 2015, connected to the municipal grid for 18 months. The University of Hawaii collected and analyzed data, and the U.S. Department of Energy verified it as the first wave power generator to supply a North American grid.

After the Hawaii test, Northwest Energy Innovations planned a megawatt-scale device with $5 million from the Department of Energy, but it was never built due to high costs. The company shifted focus to smaller, transportable devices for off-grid markets like aquaculture and remote islands, designed to fit in standard 40-foot shipping containers.

Reader's Guide

Azura represents a notable milestone in wave energy technology, being the first wave power device officially verified to supply electricity to a power grid in North America. Its 18-month grid connection in Hawaii demonstrated the technical feasibility of wave-to-grid integration, though the project ultimately revealed economic challenges. The original goal of scaling to utility-scale power (500 kW to 1 MW) was abandoned as commercially unviable, leading to a pivot toward smaller, niche applications. This shift highlights a broader pattern in renewable energy: early-stage technologies often require adaptation to specific markets rather than direct competition with established grid power. Azura's legacy lies in proving that wave energy can be harnessed and fed into a grid, while also underscoring the cost barriers that remain. Its current focus on producing both electricity and potable water for off-grid communities—such as those reliant on expensive diesel generators—reflects a pragmatic evolution. The device's design, a point absorber with 360-degree rotation, remains a reference for future wave energy converters.

Did You Know?

• Azura was originally named 'WET-NZ' from 'Wave Energy Technology-New Zealand'.
• It was the first wave power generator officially verified to supply energy to a power grid in North America.
• The device weighs 45 tons (41 tonnes) and can partially submerge beneath large waves due to low reserve buoyancy.
• The megawatt-scale version was never built because it was found not to be commercially viable.

Origins and Development Path

Azura's story began in 2006 under the stewardship of Callaghan Innovation in New Plymouth, New Zealand. The project was initially christened WET-NZ, a contraction of Wave Energy Technology-New Zealand, reflecting its national roots. The concept progressed through the Technology Readiness Level framework, moving from a TRL 1 initial concept into the micro-modeling phase designated TRL 3, before advancing to large-scale open-ocean prototypes at TRL 5/6 deployed near Christchurch. Before the Hawaii campaign, a smaller prototype survived a wave-tank trial, and a second unit was installed in 2012 for six weeks at the Northwest National Marine Renewable Energy Center off Oregon's coast, where it withstood waves up to 3.75 meters in a 12-to-14-second sea state. Both preliminary tests were successful. The device's development was later taken forward by Northwest Energy Innovations (NWEI), a partnership involving the U.S. Navy, the United States Department of Energy, and the University of Hawaii. This multi-institutional collaboration positioned the project at the intersection of academic research, military interest, and federal energy policy, giving it a level of institutional backing uncommon for early-stage marine energy ventures.

The Hawaii Grid Milestone

Starting in 2015, a version of Azura was installed at the Marine Corps Base Hawaii Wave Energy Test Site on the north shore of Kaneohe Bay, Oahu. The device floated on the surface of a 30-meter-deep berth, where it was continuously monitored over a period spanning several years. During this campaign, the generator was connected to the municipal electrical grid and delivered power to the Hawaiian community for eighteen months. The United States Department of Energy officially recognized this as the first verified instance of a wave power generator supplying energy to a power grid anywhere in North America. The University of Hawaii served as the verifying body, responsible for collecting and analyzing operational data throughout the testing period. The site's location within a military installation underscored the project's ties to the U.S. Navy, while the multi-agency oversight encompassing the Army Corps of Engineers, the Coast Guard, the Fish and Wildlife Service, and the National Marine Fisheries Service highlighted the regulatory complexity surrounding marine energy deployment.

Engineering and Operating Principles

Azura is classified as a point absorber, the most prevalent category of deepwater wave energy converter. The floating structure weighs approximately 45 tons and sits on the sea surface, where its defining feature is a circular mechanism capable of a full 360-degree rotation. This omnidirectional capability allows the device to harvest energy from both horizontal surge and vertical heave wave components, making it far more versatile than fixed-axis alternatives. The design incorporates deliberately low reserve buoyancy, a choice that permits the hull to partially submerge beneath large waves rather than being pushed entirely above them. Captured wave motion is converted into the circular rotation of the floating mechanism, which in turn drives crankshafts housed within the Azura body. These crankshafts feed a high-pressure hydraulic system that ultimately powers the electrical generator. The reliance on hydraulics rather than direct mechanical gearing represents a practical engineering compromise, allowing the device to absorb variable wave forces while protecting the generator from sudden torque spikes.

Strategic Pivot and Off-Grid Future

The original ambition for Azura was grand: NWEI, backed by an additional five million dollars from the Department of Energy, intended to refine the Hawaii-tested prototype into a full-scale unit capable of producing between 500 kilowatts and one megawatt, anchored in a 60-to-80-meter-deep berth. One megawatt would have been enough to electrify several hundred homes. However, the utility-scale pathway was ultimately abandoned after proving too expensive to be commercially viable. The company has since redirected its efforts toward a fundamentally different market. Two smaller devices have now been tested, each rated at 20 kilowatts, designed to generate both electricity and potable water for communities that currently rely on costly diesel generators. The new units are engineered to fit inside standard 40-foot shipping containers, dramatically cutting transport and installation expenses. This pivot targets off-grid applications such as aquaculture operations and remote island settlements, where the economics of wave energy are far more favorable than competing against established grid infrastructure.

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