California Energy Commission seeks to accelerate development of wave, tidal energy

The power of the Pacific Ocean eludes no one who witnesses it.

And soon, that energy may be harnessed to make emissions-free electricity.

That’s the hope of the California Energy Commission, which, under legislation passed last year, is taking a deep dive into what it would take to advance and scale up conversion of the ocean’s energy into electricity, helping the state and the nation meet ambitious zero-carbon goals.

Several kinds of technology already are in development, testing and even deployment on a minimal scale, bolstered by millions of dollars in public grants and subsidies. Still, marine energy innovation and commercial implementation lag significantly behind solar and wind, even though it offers something the others do not: constancy and predictability.

The ocean’s waves and tides persist whether it’s dark out, overcast or the wind is still.

The sea also offers huge potential as a power generator, in California and across the country.

A report out of the U.S. Department of Energy in 2021 put the nation’s potential capacity for wave and tidal energy, using existing technologies, at 1,620 terawatt-hours per year. That’s equal to about 40% of the electricity generated in the United States in 2019 and enough to power 151 million homes, according to the report from the National Renewable Energy Laboratory.

The Department of Energy’s Water Power Technologies Office on Monday called marine energy “one of the last untapped renewable energy sources.“

In California, wave and, to a far lesser extent, tidal energy potential was assessed at 141 terawatt hours per year, or about 23% of the state’s energy needs, according to newly published report on wave and tidal energy prepared for the state energy commission.

That is more than what comes from hydroelectric, nuclear, wind, geothermal and biomass sources combined. The only two larger current sources for the state are natural gas (39%) and solar (28%).

The West Coast’s narrow continental shelf makes for larger, more powerful waves than those on the East Coast, with the waters off Washington and Oregon offering the “greatest amount of extractable, near shore wave energy,” according to a 2020 study by the Department of Energy’s Pacific Northwest National Laboratory.

But Northern California also offers “significant power,” the report said, and particular potential lies along the coastline between Bodega Bay and the Oregon border, according to a 2007 report prepared for the energy commission by the Electric Power Research Institute.

Offshore wind power deployment has a big head start, with plans focused on harnessing electricity from hundreds of giant turbines floating in the ocean about 20 miles off Humboldt Bay and Morro Bay.

But wave technology appears to offer a far lower visibility than solar or wind generating infrastructure and can be deployed across comparatively smaller spatial areas for the same return in terms of power generation, experts say.

“Obviously, we’re making a big push into marine energy technologies, most notably with offshore wind,” California Energy Commission Chairman David Hochschild said during a commission workshop on wave and tidal energy last week. “But I am personally very hopeful about other marine technologies to complement that and support that.

“And I think one observation that’s important to keep in mind is that 80% of our country’s electric demand is in states that have a coast … around the world as well as domestically, and so the maturation of these kind of technologies can deliver a lot of benefits to coastal populations in terms of energy security and decarbonization.”

The workshop followed the July 23 release of a report on Wave and Tidal Energy: Evaluation of Feasibility, Costs, and Benefits, prepared for the energy commission under a state Senate bill passed and signed into law last year.

Authored by state Sen. Steve Padilla, Senate Bill 605 requires the commission to assess the potential for wave and tidal energy, as well as environmental, economic and regulatory hurdles, as part of its regular policy review.

The 91-page report is open to public comment from interested citizens and stakeholders until Aug. 22.

Among its findings: a wide variety of wave energy conversion technologies already exist utilizing different ways of capturing the kinetic energy of the ocean and converting it to electricity both for use in marine pursuits like aquaculture farms, and for integration into the grid on shore.

The equipment is designed to be deployed at different levels of the water column, capturing movement in different directions for conversion to usable energy. Some operate on the surface and others are submerged. Several have been tested at the PacWave wave energy testing lab led by Oregon State University off Newport, Ore., which facilitates testing because it has grid connections and existing permits to operate.

Significant hurdles exist in terms of cost, complex permitting, assessment of environmental impacts — on wildlife, especially — and durability in a harsh environment. The technologies are still young, so there’s a need for long-term demonstrations, according to the new report. Grid integration could be an expensive challenge, as well.

But experts and public officials are bullish about the potential for wave and tidal energy to complement other renewable resources going forward.

“I am very hopeful,” Hochschild said, “that for the long term we can together cultivate them and bring them into the market.”

State energy officials won’t begin evaluating priority areas to investigate for potential energy and tidal development until early next year for a report to be submitted to Gov. Gavin Newsom and the Legislature.

You can reach Staff Writer Mary Callahan (she/her) at 707-521-5249 or mary.callahan@pressdemocrat.com. On X (Twitter) @MaryCallahanB.