The Road to Wave Energy Commercialization

Wave energy is a renewable resource unlike any other. It's notoriously reliable, predictable, and energy-dense, serving as an important missing piece to the clean energy puzzle.

For all its promise, unlocking the power of ocean waves remains a tantalizing quest for energy developers.

While the first known wave energy patent was filed by French polymath Pierre-Simon Girard in 1799, it wasn't until the first decade of the 21st century that pilot-scale deployments demonstrated success for systems capable of providing utility-scale power. Even more importantly, a number of promising companies are nearing commercialization, which could create momentum for a wave energy market capable of meeting upwards of 30% of global electricity demand in the coming years on our road to netzero.

CalWave, a California-based wave energy developer, has now validated/proven its award-winning technology in the open ocean and is continuing to advance forward in the marine energy industry’s efforts to demonstrate and deploy utility scale technologies connected to the grid. 

A NEW GENERATION OF TECHNOLOGY

CalWave’s xWave™ technology takes on the form of a submerged pressure differential wave energy converter. The device is anchored to the seafloor and can operate at a range of different water depths and distances from shore. As waves pass overhead, the water level above the device rises and falls, creating a pressure gradient that causes the device to orbit from its moored position. Generators within the device resist this relative motion and convert it into electricity that is then transported back to shore via a subsea cable. 

Not only does the xWave’s submerged design enable optimal performance by capturing energy from multiple degrees of freedom, but it also allows for protection from aggressive swells and storms that don’t contribute to total generated power meaningfully. The system’s unique wave load management mechanisms for minimizing extreme wave loads and promoting survivability are comparable to pitch and yaw control in wind turbines. 

As for survivability in the ocean’s corrosive environment, the xWave utilizes the same materials and techniques as other vetted offshore technologies. The system’s hull is protected by environmentally acceptable anti-corrosion and anti-biofouling coatings, in addition to sacrificial anodes, which add cathodic protection against corrosion for uncoated surfaces.

PROGRESS AT SEA IN 2022

In July 2022, CalWave successfully concluded its open-ocean wave energy pilot after 10 months of continuous operation off the San Diego coast. The pilot unit, named x1™, deployed in September 2021 and represented a scaled-down version of CalWave’s x100™, 100 kilowatt system. The project was supported by a US Department of Energy (DOE) award with the goal of demonstrating CalWave’s scalable and patented xWave technology as a cost-effective, sustainable solution for power generation. Initially, the demonstration was contracted to run for six months, but was extended for further data collection based on high reliability of the system and the need for zero interventions during operations. Not only does the demonstration represent California’s first at-sea, long-duration wave energy project, but it also serves as a critical step toward proving wave power as a commercially viable renewable resource.

CalWave’s pilot verified its xWave system as effective for overcoming the key challenges of performance, reliability, survivability, and cost. The xWave system validated the efficiency of its novel control mechanisms, achieving its intended state of fully autonomous operations in November 2021 and demonstrating over 99% system uptime throughout the deployment. A fully submerged design enabled the technology to survive several major storms, including two representative of the largest storms in a typical 10-year period. The xWave’s novel wave load management mechanisms allowed for rapid and effective reduction of storm loads on all parts of the system, ultimately proving that structural overdesign is not needed for performance and cost-efficiency. The advanced controller and onboard sensors enabled continuous health monitoring and remote inspections through a web-based portal. A subsea cable exported the power and data generated to the Scripps Institute of Oceanography research pier. 

Environmental monitoring data was also gathered in collaboration with the Pacific Northwest National Laboratory’s Triton Initiative, and the third-party findings reported no visual or acoustic impacts of the technology on surrounding marine ecosystems.

THE NEXT STEPS FOR CALWAVE

In January 2022, CalWave was awarded the single largest award of $7.5 million from the U.S. Department of Energy’s latest $25 million commitment to accelerate ocean energy development to further develop their xWave technology for use on local energy grids and microgrids.

CalWave has been contracted to build a 100 kilowatt version of the xWave architecture for a two-year deployment off the coast of Oregon at PacWave South, the nation’s first accredited, grid-connected, pre-permitted wave energy test facility.

OPPORTUNITIES FOR SCALING & ACCELERATION

CalWave is committed to providing reliable, cost-effective wave energy technology for sustainable energy access, and is continuing to follow the US DOE’s product commercialization roadmap to de-risk and scale the xWave.

While testing wave energy converters in real ocean conditions is essential for ensuring that devices will operate as expected when deployed without requiring significant capital expenditures or additional time for commissioning, moving beyond the demonstration stage will be the next big hurdle for developers to overcome.

At this inflection point, it’s important to consider the economic and social opportunities for both public and private sectors alike in scaling proven wave energy technologies to a size that makes them economically viable.  

Offshore wind and wave energy can serve as complements to boost power availability, reliability, and cost benefits. The opportunity to combine wind and wave farms should be explored as a means of increasing the combined capacity factor of technologies while sharing the same electrical export infrastructure for year-round baseload renewable energy production.

Public policy is creating favorable conditions for wave energy industrialization. For example, the US Inflation Reduction Act provides investment certainty for new marine energy infrastructure. This recently signed legislation creates a 10-year investment tax credit (ITC) / production tax credit (PTC) framework for marine energy projects, offers parity for marine energy under the existing PTC framework, with ITC opt-in, through 2024, and lowers the threshold for projects to qualify for the PTC from 150 kilowatts to 25 kilowatts. 

Wave energy can become a reliable job creation machine. Despite the lingering effects of COVID-19 and the growing energy crisis, worldwide renewable energy employment increased by 700,000 new jobs, reaching 12.7 million last year, according to the International Renewable Energy Agency. For wave energy to reach its projected penetration rate, millions of local jobs will need to be created.

Implementing wave energy at scale will help close the emissions gap and support achievement of the world’s sustainable development goals. Ocean-based clean energy solutions are projected to displace 1.9 gigatons of greenhouse gas emissions annually by 2050. Wave energy will presumably make up the majority of sector displacements as the largest untapped, power-dense resource on the planet.

To read the full article, which was featured in ON&T October 2022, click here.