In high school, Marcus Lehmann built a solar-powered race car. It wasn’t just a fun project. After hearing the Intergovernmental Panel on Climate Change urgently call for more renewable energy, the young engineer decided to dedicate his career to thwarting climate change with new renewable energy solutions. The race car was just the beginning.
Today, as the CEO of CalWave Power Technologies, Inc., Lehmann and his team build machines to capture a different, newer renewable energy source: the energy of ocean waves. Through decades of development, the solar power and wind energy industries have homed in on the most cost-effective and efficient designs to transform these energy sources into electricity. But the marine energy industry—which develops technology that creates electricity from ocean waves, currents, and tides—is in an earlier stage of development. Several architectural designs are currently vying for commercial success.
In September 2021, one of those designs—CalWave’s xWave—got a step closer with the company’s (and California’s) first at-sea, long-duration wave energy pilot project. The launch edges the technology closer to providing grid-connected electricity for coastal communities worldwide.
“Wave power is regarded as the largest unused renewable resource and the third-largest technical feasible resource,” said Lehmann, who co-founded California-based CalWave in 2014.
Wave energy is also a good complement to other renewable energy resources. When the sun sets and winds slow, waves keep moving at a steady pace through all four seasons. Combined, the three renewable resources could provide the grid with reliable power both day and night and year-round. On its own, wave energy could satisfy up to 34% of the United States’ electricity needs. But the benefits extend beyond U.S. coastlines: Offshore, portable wave energy devices could help power the growing blue economy, including sensor-equipped sea drones that collect data on ocean ecosystems for marine research.
“Marine energy systems, like CalWave’s xWave, are exciting not just because they can provide clean, carbon-free energy to coastal communities,” said Yana Shininger, a technical project officer for the U.S. Department of Energy’s Water Power Technologies Office (WPTO), which provided funding to CalWave to design, build, and test its proprietary technology. “From powering autonomous vehicles for ocean exploration to transforming salt water into fresh for remote island communities or disaster recovery situations, marine energy devices have a vast range of potential applications.”
Today, the technology is at an inflection point. CalWave’s xWave uses a promising architecture. But before marine energy companies like CalWave take their designs to the market, they must first take them to the ocean, a salty—and therefore corrosive—and volatile environment.
On Sept. 16, 2021, CalWave took that salty plunge: The company deployed its xWave prototype off the University of California San Diego’s Scripps Institution of Oceanography research pier in San Diego, California. For six months, the device will rock in the waves 1,800 feet—or about six football fields—off that pier. There, it will transform the ocean’s oscillating motion into electricity, which is then transported back to shore.
During severe weather events, CalWave’s xWave has some tricks to weather even the most tumultuous storms. While many wave energy developers cloak their machines in heavy steel, the xWave design uses a far lighter, less expensive technique. Instead of floating on the ocean’s surface, the xWave operates while submerged at different depths. When more destructive swells roll in, the xWave autonomously drops lower to avoid them. Operators can also remotely shut the device down to protect it during storms.
As a bonus, submerging the xWave keeps it hidden, ensuring beautiful ocean vistas stay that way.
In the San Diego sea trial, the 15-foot-long xWave is anchored at the test site and deployed in water nearly 100 feet deep. But these numbers are negotiable; the xWave can be smaller or larger to suit a customer’s needs and can work in a variety of depths and distances from shore.
During this trial, CalWave will collect data on how the xWave operates out at sea. But the team will also collect information on how well marine energy devices cohabit with marine ecosystems. Collaborating with the Pacific Northwest National Laboratory’s Triton Initiative—a project funded by WPTO to research environmental monitoring technologies and methods—CalWave will observe the xWave with a Boxfish 360 video camera and three different sound monitoring tools: Integral Consulting, Inc.’s noise spotter buoy, a drifting hydrophone, and three long-term, bottom-mounted hydrophones. Because wave energy is still so new, it’s important that scientists collect data on machine-ecosystem interactions. Although only a few offshore deployments have collected this valuable information, existing data show that the risks for single devices are relatively low.
Researchers also need to monitor how the marine environment impacts their machines. Shifting sand and stones can collide with or get lodged in devices. CalWave will submit data on all these environmental interactions to an open-source, global, collaborative report to help ensure the safe adoption of robust marine energy technology worldwide.
After the six-month California deployment, CalWave plans to install and operate a larger xWave unit at PacWave, the first accredited, prepermitted, and grid-connected wave energy test site in the United States. The site can test up to 20 wave energy converters at a time and send up to 20 megawatts of electricity through a preinstalled cable onto the local grid.
But CalWave has bigger plans for wave energy. For years, the company has been an active member of the National Hydropower Association’s Marine Energy Council, which is calling for domestic marine energy to reach at least 50 megawatts by 2025, 500 by 2030, and 1 gigawatt—similar to the power that more than 3 million solar panels can produce—by 2035.
With its long-term California sea trial, CalWave’s xWave inches the industry closer to that gigawatt and the country closer to the Biden administration’s goal of a carbon-free energy sector by 2035.
This project received support from the U.S. Department of Energy’s Water Power Technologies Office, the University of California San Diego Scripps Institution of Oceanography, the National Renewable Energy Laboratory, Sandia National Laboratories, DNV-GL, and the University of California Berkeley.