The International Energy Agency’s Technology Collaboration programme on Ocean Energy Systems (OES) has today published in-depth interviews with six key players in the ocean energy sector. Our CEO and Co-Founder, Marcus Lehmann, explains the value proposition of its ocean observing platform powered by wave energy. The original Alternative Market for Ocean Energy report can be downloaded here.


CalWave xNode is a technology platform providing any offshore operation access to reliable power and data. CalWave was the winner of the Ocean Observing Prize launched by the US Department of Energy, in which competitors submitted novel concepts and ideas to integrate ocean observing sensors and platforms with marine energy systems.


Can you please describe your concept?

The CalWave xNode is enabling the Ocean Internet of Things by providing access to power and data offshore. The xNode is a versatile, adaptable, and resilient ocean observing platform with built-in power generation. It is lightweight and low cost, resilient for storm survivability, and easily stores, ships, and deploys. The xNode facilitates and improves a range of existing and novel offshore missions.

A standard baseline ocean science sensor suite ensures that every mission maximizes data collection and cross-functional interest. The modular scientific payload compartments can be equipped independently and configured easily in the standardized hull.

In addition to providing remote power and data offshore, the xNode stands out through innovative features such as a digital twin, autonomous shelter/survival functions, onboard edge computing, and a lightweight and compact size enabled by an inflatable hull.


What was your motivation to develop this concept?

In 2017 as a follow up to the US Wave Energy Prize that had the goal to identify wave technologies that can become cost-competitive with other utility-scale renewables, CalWave was awarded a contract from the U.S. Department of Energy to demonstrate a scaled version of our MW level xWave technology in open water. Next to these, our team participated in the early workshops of the US DOE that lead to the Powering the Blue Economy (PBE) initiative and further advanced our interest in solutions for the blue economy.

Since then, our team has designed, built, and tested critical subsystems and elements such as our drivetrain (power take-off unit, or PTO) suitable for our open ocean demonstration scheduled for Q3 2021 in San Diego, CA. Together with our development partners at UC Berkeley, Sandia National Laboratory, and NREL, we’ve built a hardware in-the-loop test facility to validate the overall performance of our PTO, optimize advanced control strategies, and obtained numerical models for simulations. This PTO, is now a mature subsystem we can utilize for lower power units specifically designed for end-users of the blue economy, such as the xNode.


How do you see your project moving forward?

Our team has continued to conduct customer discovery to narrow down specific use cases and requirements, such as continuous power needs that inform the onboard energy storage capacity, types and dimensions of sensors that allow dimensioning of the variable payload compartment.

After our open ocean demonstration of the xWave architecture in 2021, we are planning to offer the xNode as a stand-alone product line to the market in the near future.

Next to that, CalWave is planning to demonstrate the X100 at PacWave in Oregon the coming years. The X100 is the 100 kW product line of the xWave architecture that is scalable to MW levels. The xWave class is operating fully submerged and next to performance, incorporates critical load management features. These are essential features for MW level wave farms that operate for 20 years+ as standalone wave farms or collocated with offshore wind farms.


Are you also looking for other market applications for your wave energy concept? And if so, why do you consider you technology appropriate for these markets and which benefits in particular you see?

Our xNode is a technology platform providing any offshore operation access to reliable power and data. We’ve received interest from operators of offshore aquaculture farms, navigational aid systems, long-term monitoring stations of remote environmental stations, disaster recovery first responders and other remote microgrids. Having continuous power and data connectivity on the surface via satellite is the critical missing piece needed to enabling permanent offshore operations, such as resident AUVs or ROVs.

Next to that, we are offering a version of the xNode called the HydroNode. It will deliver fresh water to remote coastal communities, providing a rapidly deployable and easily operated and maintained system for locally generated desalinated water to support disaster relief. Here we can pair with an existing or integrated RO system for wave-powered desalination.

With this product line, our team is currently contesting in the U.S. DOE Waves to Water Prize that will host at sea testing at Janett’s Pier in North Carolina in the final stage of the competition in 2022.


The development of these projects involves a wide variety of risks, including technical, regulatory and financial. What do you anticipate to be the main barriers to integrate wave energy technology in ocean observation platforms at large scale and how could they be overcome?

There are existing ocean observation platforms available today using energy storage technology (fuels and/or batteries) and renewables such as solar and micro wind turbines. 

The main value of wave power for ocean observation platforms is its high energy density relative to wind and solar. That means with the same weight of a device and space, wave power can generate more power as the energy density is up to 20-60 times denser compared to other renewables (annual average wave power densities range from 20-60 kW/m of coastline).

The main motivation to use renewables for ocean observation platforms is that we can remove the frequency of human intervention for refueling. Thus, the critical barrier to prove the value proposition of wave power technology for ocean observation is ease of deployment, robustness, and reliability. This barrier is overcome by sea trials often carried out at pre-permitted test sites such as here in the U.S. WETS in Hawaii or PacWave in Oregon. Advanced sensor technology and digital tools, including our digital twin that enables predictive maintenance, can further improve reliability going forward.


If support measures are put in place to overcome those barriers, can you identify the responsible stakeholders for delivering solutions, such as, governments, supply chain, research sector, etc, and what would be the expected improvement in terms of your project pipeline and cost reduction that could be achieved?

As mentioned, testing at sea in the same environment and depth as our end-users is critical which test sites can support. Next to that, accelerated lifetime testing of critical subsystems and components will accelerate the commercial adoption of new technologies. We’ve seen similar key enabling test facilities in the wind industry where blades are tested for fatigue and generators for controls in large dyno test stands.

Cost is certainly a consideration for all end-users, so support mechanisms to achieve higher production volume for new solutions can help quickly bring the initial cost down. This allows for wider adoption and even more cost reductions due to volume. In summary, mechanisms that help to get the ball rolling overcoming the initial inertia (or the first 10-50 units) are important. This support can come in form of loan guarantee programs or e.g. financial incentives to end government or private sector end-users.