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Davis, California

Thursday, October 28, 2021

Excess carbon dioxide to be stored underground

It may sound too strange to be true, but engineers are about to begin work on a project that would keep carbon dioxide out of the air by injecting it into the ground.

A pilot project will equip a Kern County power plant with the ability to capture 1 million tons of carbon dioxide byproduct and inject it into geologic formations 7,000 feet below the Earth’s surface.

“These are underground formations where oil and gas have been pumped out before, so there’s space in there where you can put the carbon dioxide,” said Joan Ogden, an environmental science and policy professor at UC Davis. “Normally, it would be released into the atmosphere and contribute to climate change.”

Most power plants in California, including the test plant, use natural gas to generate electricity. Carbon dioxide is a byproduct of the process and is normally released into the atmosphere or bottled in small amounts for other uses.

As with any new technology, there are health and safety concerns.

“The question is will it stay down there,” said Ogden. “There’s a lot of work going on right now to make sure that what you put down there stays.”

Carbon dioxide is not flammable but is an asphyxiant in large quantities, she said.

“Carbon dioxide is heavier than air, so it tends to stay near ground level,” she said. “If you had a big leak all of a sudden … you’d want to put it where the wind could disperse the CO2.”

Ogden said this is not difficult to achieve, and a plant would never be sited in an area where a leak would present a lethal danger.

The project is being supported by a new $65.6 million grant from the U.S. Department of Energy to the California Energy Commission. An additional $24.9 million is being provided by the partners of the West Coast Regional Carbon Sequestration Partnership.

The test plant will be constructed by Clean Energy Systems of Rancho Cordova and will have a 50 megawatt capacity, enough to power 50,000 homes, CEO Keith Pronske said in an e-mail interview.

Pronske, who graduated from UC Davis with a degree in mechanical engineering, said the technology is based on hardware developed and tested at UC Davis in 2001. A 500-megawatt natural gas power plant produces about 2 million tons of carbon dioxide per year, he said, but he doesn’t expect to run out of underground storage space anytime soon.

“Studies show there are sufficient geological structures to store quantities of CO2 for several centuries,” Pronske said. “Presumably, we’ll be on to other fuel sources before we run out of storage space.”

The results of the pilot project will be analyzed and the lessons from this will be applied to future uses, said California Energy Commission spokesperson Adam Gottlieb. Carbon sequestration works better in some locations than in others, he said.

“The central valley is geologically perfect for this type of research because of the way the earth is structured, the way the strata are configured,” he said. “Other regions are using different versions of the application.”

The pilot project is a step toward a sustainable future, he said.

“We are clearly stepping through the 21st century to make California’s carbon footprint noticeably smaller,” he said. “California has always been a pioneer…. When it comes to this type of technology, California will be both an industry leader and an environmental leader.”

The technology could have serious implications for electric vehicles. Although electric vehicles don’t burn fossil fuels, some critics say they don’t help climate change because emissions still happen at the power plant where the electricity is generated. With a zero-emissions power plant, however, this would not be a concern.

“If you combine zero-emissions power plants with electric cars, you’ve got a home run, as there would be no carbon emissions from stationary or mobile sources,” Pronske said.

For more information on carbon sequestration technology or the pilot project, go to westcarb.org.

 

JEREMY OGUL can be reached at city@californiaaggie.com. XXX

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