A wave energy converter sits offshore from Scripps Institute of Oceanography in La Jolla. The Oakland-based company CalWave partnered with the research institute to test the technology in hopes of using waves to make clean electricity. (Photo courtesy of CalWave)
Ocean energy could take its place alongside solar and wind in helping to decarbonize the power grid
By Brooke Staggs / Orange County Register / December 27, 2022
If you’ve ever gone surfing or felt seasick or simply watched as the ocean crashed onto shore, you know the power that waves hold. The potentially world-changing question is, can that power be harnessed in a cost-effective way to produce clean, reliable electricity?
Solar and wind dominate discussions about renewable energy. And with only so much land available for such projects, interest in using open seas for floating solar and offshore wind farms is growing. That was on display earlier this month, when the federal government held the first auction for wind farms off the coast of California.
But there’s also new funding, research and commercial attention focused on finding ways to use qualities of the ocean itself, rather than just its real estate, to make renewable energy. In some places that might mean tapping into strong ocean currents, fluctuating water temperatures or extreme tides. Along the West Coast, that means wave energy, where devices set at or just below the surface use the bobbing motion or pressure of ocean waves to drive turbines that generate electricity.
With nearly half of Americans living within 50 miles of a coastline, the ocean offers significant potential to help the United States hit its goal of net zero emissions by 2050 and to help California get there by its net-zero deadline of 2045.
There’s more than enough power in all marine energy along U.S. shores to meet current electricity needs, per the latest report from the National Renewable Energy Laboratory. If just a tenth of the marine energy that can be captured with today’s technology was harnessed, the report states the ocean could power some 22 million homes nationally and 1.3 million in California. That would replace up to 7% of the electricity used in the country today with emissions-free, renewable energy.
So why hasn’t wave energy exploded the way solar and wind energy have in recent decades? Brian Polagye, a mechanical engineering professor at University of Washington who studies marine energy, said one major reason is because, while wind turbines have been around since the Roman era, talk of wave energy technology didn’t really start until the 1970s. That means there’s no gold standard yet for what wave energy converters will look like, with companies still pursuing at least eight different technologies to see which can break through by withstanding harsh ocean conditions and producing the most energy at competitive prices.
No “goldilocks” site for such projects has been identified yet either, Polagye said. There’s solid potential from Southern California to the top of Washington, with pluses and minuses to each option.
But a key test for wave energy potential on the West Coast is coming soon.
Construction is underway on a site called PacWave, seven miles from the shores of Newport, Oregon. The Department of Energy, which is helping to fund and develop the project with Oregon State University, says it will be the nation’s “first accredited, grid-connected, pre-permitted, open-water wave energy test facility.”
If all goes as planned, some companies that won federal grants to test at PacWave say they aim to “splash” their devices there in 2024 and launch commercial wave energy converters for small projects as soon as 2025.
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Crews lift a wave energy converter made by CalWave, an Oakland-based company, before sending it out for a 10-month test in open waters off the coast of San Diego. CalWave hopes to help pioneer commercial development of clean wave energy. (Photo courtesy of CalWave)
Wave energy converters could then be used within a few years to help power at-sea operations, such as aquaculture and ocean research, or isolated communities that now rely on pricey, dirty energy such as diesel-fueled generators. That’s a development Polagye said he sees as a “near certainty.”
As for scaling such projects up, to create arrays of wave energy converters that could feed state energy grids? David Duquette, chief executive of Massachusetts-based Littoral Power Systems Inc., which won a $4 million grant to test a device at PacWave, puts it like this:
“We have a lot of work to do.”
Testing the waters
In one sense, Polagye points out, wave energy is another form of both sun and wind energy.
As the sun heats the air in different parts of the world at different times, the hot air rises and cold air moves around to displace it, which creates wind. Wind then moves over the ocean, picking up water along with it and triggering waves. But unlike solar energy, wave energy happens around the clock. And it’s more reliable and easier to predict than wind energy, making it attractive from an efficiency perspective.
To capture the solar energy that’s been transferred to waves, researchers have been studying eight main types of technology with fun names like “bulge wave” and “oscillating wave surge converter.”
The first type of wave energy technology to feed electricity to a grid was an attenuator — a snake-like metal structure that floated parallel to waves and used the motion to turn turbines inside — called Pelamis Wave Energy Converter. That device was successfully tested off the coast of Scotland from 2004 to 2007. The Scottish company behind that project then developed a small wave energy farm off the coast of Portugal, with plans for others. But funding stopped coming and the company folded in 2014.
Scotland is still home to the most advanced wave energy testing site in the world, Polagye said. But advocates for wave energy in the U.S. hope PacWave’s 20-megawatt test site might soon give that facility a run for its money.
PacWave has been under development since 2016. Construction started in June 2021 and should wrap up in 2023, with crews installing cables to transmit power from test devices back to utilities. There will also be offices, a control room and a visitor’s center on shore, plus a research vessel available to monitor the site.
Littoral Power Systems will head to PacWave to test a control system for point absorber technology, where piston-like structures on or inside upright columns bob with the waves and power an onboard motor.
The company awarded the biggest pot of money from the Department of Energy to test off the coast of Oregon is Oakland-based CalWave, which got $7.5 million to deploy its submerged pressure differential device called xWave. The sealed, octagon-shaped device, which is about the size of a small bedroom, gets towed out by boat and anchored to the seafloor to sit just below the surface. As waves rise and fall above the blue box, pressure is created that triggers a drivetrain inside to create electricity.
CalWave founder Marcus Lehmann started developing the technology a decade ago when he was a graduate student at UC Berkeley. This fall, in partnership with Scripps Institution of Oceanography, his company completed California’s first sustained wave energy test project off the coast of San Diego. The results were promising.
After 10 months at sea, the xWave was still operational despite two heavy storms. It operated autonomously 80% of the time without needing any interventions. And while it wasn’t connected to the grid, Lehmann said xWave successfully sent power over to Scripps via an existing transmission cable.
CalWave is now working on a 100-kilowatt version of the xWave, which will be tested at PacWave for two years. Lehmann said he’s not yet sure how long into that testing window it might be before they could get the xWave certified to begin commercial distribution. But he said he’s already lining up financing and production capacity for a couple potential projects as soon as they get the green light.
Location, location, location
CalWave has signed a memorandum of understanding to develop some of their first small, commercial projects in remote parts of Alaska that need access to reliable power.
The company also is looking to developing island states as a potential market. Many now rely on imported diesel for their power, which is expensive and dirty. And since energy demand isn’t huge in most of those places, Lehmann said they’re ideal candidates for wave energy microgrid projects.
There may also one day be federal funds available to help support such efforts in developing nations. During the United Nation’s COP27 climate conference in Egypt in November, richer governments agreed to support a “loss and damage” fund that would help poorer nations that are being ravaged by climate change despite contributing very little to the problem. Using some of that money to help struggling island nations — which face the most serious threat from climate impacts such as sea level rise — transition to reliable, clean wave energy makes sense to Polagye.
Beyond those smaller projects, the National Renewable Energy Laboratory reports that the entire Pacific Coast is ideal for wave energy development. But Polagye said the jury is still out on which parts of the coast will prove the best for such projects.
Wave energy gets stronger as you move further up the coast, toward Oregon and Washington, which means more potential to generate power. But it also means harsher storms, which can ravage equipment and force companies to curtail devices or take them offline for some period of time. So in the long run, Polagye said there might be less risk and more reliable power from wave energy projects off the California coast. And the closer such projects could be to large population centers, the more demand there will be.
Southern California’s crowded coast does present some logistical challenges, with heavy shipping lanes, military resources and offshore recreation. But Lehmann said he’s confident that there’s still room for local wave energy projects, pointing to how places like Germany have found ways to make crowded ports, fishing and offshore renewable projects work. And with devices like his, which sit below the surface, there’s no visual impact from shore.
There is a good argument to be made to co-locate wave energy parks with offshore wind farms, Lehmann said. With potential to share transmission lines and some possible regulatory overlap, he said it could help streamline such projects for both wind and wave developers.
Key hurdles remain
Getting such projects permitted will be challenging, Duquette acknowledged. But perhaps less so than some other types of renewable energy.
Since many wave energy converters don’t have exposed moving parts, for example, they pose limited risk to marine life. The main concern is for larger mammals that might become entangled in mooring lines, something that’s likely to raise alarms for wildlife advocates.
But the biggest hurdle wave energy faces right now, advocates said, is simply cost.
While there’s substantial money available today for research and development, Duquette said wave energy still retails for roughly three times more than other sorts of renewable energy. In that way, wave energy today is at a similar place as solar and wind energy were in the 1980s.
But as technology advanced, and demand for renewable energy increased, prices for solar and wind dropped precipitously. And as of five years ago, Polagye noted it became cheaper to build a new utility-scale wind or solar farm than to keep operating an existing coal power plant.
Already Duquette said wave energy costs are dropping as public funds flow. So if these latest tests prove effective, it may take several years, rather than several decades, for wave energy to become competitive. And if prices level out, reliable wave energy could well pencil out to be more cost effective than offshore wind.
Those are a lot of “ifs,” though. From where Duquette sits, he said it’ll be “a long, long, long time” before wave energy might power state grids.
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