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Practical Magic

A dream team for ocean carbon capture?

A group of former Google, SolarCity and Tesla executives in April snagged $20 million in what is being called the largest ocean-based carbon removal investment to date.

Ebb Carbon system

Ebb Carbon is developing and electrochemical approach to carbon removal that "intercepts salty water" from facilities such as desalination plants, salt production or aquaculture operations. Image courtesy of Ebb Carbon.

If there was any doubt the ocean is increasingly becoming a focus of carbon capture entrepreneurs, you may set it aside.

Three months after early-stage startup Captura — fronted by an experienced executive in the nascent carbon removal sector, former Carbon Engineering CEO Steve Oldham — raised $12 million in Series A funding, a group of former Google, SolarCity and Tesla executives in April snagged $20 million in what is being called the largest ocean-based carbon removal investment to date.

Like Captura, their company, Ebb Carbon, is betting electrochemistry can help speed up the ocean’s natural ability to sequester atmospheric carbon dioxide. It hopes to set up shop near desalination plants, seaside power plants, aquaculture operations, salt producers and other coastal industrial facilities, where its system can "intercept," treat and capture salty water flowing through wastewater pipes. That water is treated using low-carbon electricity to produce hydrochloric acid and sodium hydroxide. The acid is diverted from the ocean, but the other solution is returned, where it enhances the ocean's natural ability to capture sequester carbon dioxide.

Ebb Carbon’s new funding, led by Prelude Ventures and Evok Innovations, was closed in two rounds. The money will go toward building two of its first commercial systems: The first, which will capture a relatively tiny 100 metric tons of carbon annually, should be in place by late 2023; the second, with a sequestration capacity of 1,000 metric tons annually, will be in place "shortly thereafter," according to the funding press release

"We are excited by the potential for Ebb to remove gigatonnes of CO2 annually," said Gabriel Kra, managing director and co-founder of Prelude Ventures, in a statement. "The team has previously demonstrated their abilities to build and scale industrial machinery, and has invented a technology that is a least-cost solution for ocean carbon dioxide removal."

A modular approach

Ebb Carbon CEO and co-founder Ben Tarbell, a mechanical engineer who was SolarCity’s vice president of products for seven years before leading climate tech research at Google X, cited many similarities between the current state of carbon removal tech and the solar sector two decades ago. "There is a clear recognition of the need, and we need to build the technologies to do this at scale in order to have any hope" of removing 10 gigatons of CO2 annually to keep temperature increases below 1.5 degrees Celsius, Tarbell told me.

The rest of Ebb Carbon’s executive team boasts equally noteworthy credentials. The chief technology officer, Matt Eisaman, is a Google X alumnus with more than a decade of research experience at Stony Brook University and Brookhaven National Laboratory; the vice president of engineering, Dave Hegeman, developed batteries for Tesla for years; and the chief engineer, Todd Pelman, has experience with electrodialysis systems and marine engineering. 

As explained earlier, the technology works by speeding up the natural process of ocean alkalinization. It captures water at existing facilities and uses electrochemistry to turn them into saltwater solutions. When that water is returned to the ocean, the chemical reaction creates a bicarbonate that is absorbed and stores CO2. Ebb Carbon’s pitch is that this is a long-lasting solution that can help store CO2 for at least 10,000 years. Meanwhile, the alkalinity helps reverse acidification in the local waters.

Ebb Carbon is designing its system to be modular and relatively simple to transport; depending on the sequestration potential of the installation sites, the company and its site partners will install multiple units. That said, the system isn’t all that diminutive in its current iteration: The 100-ton version fits roughly on a flatbed truck, although those units will be configured differently for sites with large sequestration potential.

When I asked Tarbell about partners (and about the sites of its initial installations), he declined to be specific. "It’s essentially anyone that has the infrastructure that is already pumping water in and out of the ocean. We are essentially borrowing their water," he said.

One question that could pose a dilemma for Ebb Carbon: How much CO2 is safe to add back to the ocean? Tarbell believes it’s a non-issue, and by focusing on existing facilities for the advance guard of its deployments, Ebb Carbon should be able to get around potential permitting issues while keeping its own capital costs lower, Tarbell said. The company cites data suggesting that if all the 150 gigatonnes of CO2 that must be removed by 2050 were stored as oceanic bicarbonate using the Ebb Carbon process, it would. add only 0.11 percent to the ocean's existing CO2 stores.

The funding deal is the latest validation for Ebb Carbon’s approach. In December 2021, the company inked a carbon removal purchase contract with Stripe Climate fund under which it will receive $500,000 for removing 256 metric tons of CO2 by Sept. 1, 2024.

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