A North Dakota Utility Wants to Build the World’s Largest Carbon Capture Facility at a Power Plant

The Milton R. Young Station, close to the town of Center in North Dakota, is as unremarkable as coal-fired power plants come. But if its owner Minnkota Power Cooperative has its way, the plant could soon be famous the world over.

The Grand Forks-based electric cooperative has launched Project Tundra, an initiative to build the largest power plant-based carbon capture facility in the world, with construction commencing as early as 2022. If Minnkota Power raises the US $1 billion the project requires, it plans to retrofit the station with technology the cooperative claims will capture more than 90 percent of carbon dioxide (CO₂) emitted from the plant's larger generator, a 455-megawatt unit. The effect will be the equivalent of taking 600,000 gasoline-fueled cars off the road.

"The company is very committed to finding a way to keep this coal-fired plant operating," says David Greeson, a consultant working on Project Tundra. "But they're also equally committed to finding a way to do something about carbon dioxide emissions, and that's why they're spending the money to develop this project."

Carbon capture-the process of sequestering CO₂ at its emission source before it's released into the atmosphere-has attracted growing attention as a solution to global warming. For the world to meet the 2-degree Celsius goal set forth in the 2015 Paris Climate Agreement, it needs to combat carbon dioxide, the primary greenhouse gas responsible for roughly three-quarters of emissions. Estimates suggest that carbon capture can help cut close to 10 percent of such emissions by 2050.

To sequester CO₂ from the Young station, Project Tundra will make use of technology similar to that employed at the only two other existing carbon capture and storage (CCS) facilities operating at power plants in the world-Petra Nova in Texas and Boundary Dam in Saskatchewan, Canada.

The CO₂-removal process begins by passing the flue gas through a scrubber to remove impurities and lower its temperature. The gas then enters an absorber, which contains a liquid-based amine solution that binds to CO₂. Heat is applied to release the gas from the amines and the extracted CO₂ is then compressed. Project Tundra plans to pump the liquid CO₂ into sandstone rocks that lie just over a mile beneath the nearby lignite coal mine, where it will be stored permanently.

Tundra, one of 51 large-scale CCS projects worldwide (with 19 in operation and the rest under construction or in various stages of development), was launched four years ago-to mixed reviews. Some experts, such as David Schlissel, the director of resource planning analysis at the Institute for Energy Economics and Financial Analysis (IEEFA), believes adding carbon capture is just a way of "bailing out old, expensive, inefficient coal plants."

More than half of the coal-fired power plants in the United States are over 40 years old. Built in the 1970s, the Young station falls squarely in this category. Upgrading them to accommodate CCS retrofits would be costly, notes Schlissel in a 2018 report [PDF] he co-authored on the subject.

Additionally, a coal plant that is coupled with CCS technology may actually be more expensive to run because of an increase in parasitic load, he says. A coal plant uses between five and nine percent of the electricity it generates to run the equipment it needs to operate. But adding carbon capture, an energy- and water-intensive process, pushes this parasitic load up to much as 33 percent, he says.

According to IEEFA estimates, that more than triples the cost of electricity generated at a coal plant, from $30 to $96 per megawatt hour (MW/h). As a result, coal becomes even less competitive against solar and wind-generated electricity, which can be purchased today for as low as $35 and $21 MW/h respectively.

"Are we looking for perfect or are we looking for good?" -James Mulligan, World Resources Institute

This is especially true in parts of the country which are well suited for use of renewables, says Schlissel. North Dakota, for instance, gets a large amount of wind that can provide electricity to the grid at very low market prices. "So the ratepayers of the entities that buy the power from the coal plant are paying a lot more than they would otherwise," he says.

But replacing coal and other fossil fuels with renewables isn't a straightforward solution, says James Mulligan from the World Resources Institute. "The question becomes: 'Is there actually an opportunity to do that politically?'" he says.

Support for the coal industry remains strong in many pockets of the country. Although U.S. reliance on coal has steadily decreased, the fuel still supplies close to a quarter [PDF] of the country's electricity needs. Globally speaking, this figure is closer to 40 percent, with many countries in Asia favoring coal for its availability and low cost.

"It's definitely better to be capturing that CO₂ than letting it continue to be unabated," says Mulligan. "Are we looking for perfect or are we looking for good?"

Carbon capture projects like Project Tundra, he says, form part of the multi-prong approach the United States needs to adopt in order to achieve its 2050 carbon-neutrality goal of emitting only two gigatons of CO₂ per year.

But there are less expensive ways to reduce the U.S. carbon footprint, says Schlissel. CCS projects have a bad track record, mainly due to the absurdly high costs involved in building them. Of the nine demonstration projects funded by the Department of Energy's advanced fossil energy research program between 2010 and 2017, totaling roughly $1.12 billion, only one power plant-based one remains operational today: the 240-MW Petra Nova.

Even up-and-coming projects, including Project Tundra and the San Juan Generating Station in New Mexico, don't seem promising. "Each project we look at just doesn't look financially viable," says Schlissel.

Greeson disagrees. Project Tundra has already received $9.8 million from the Department of Energy alongside $15 million from North Dakota's lignite research fund. With additional funding from the 45Q tax credit scheme [PDF], he believes the project will secure the money it needs to begin construction.

Under the scheme, investors will receive $50 for every metric ton of CO₂ sequestered and stored. The plan is for Project Tundra to capture 3.5 million tons of CO₂ annually and the subsidy will last for 12 years. "So that's $2.1 billion available in tax credits for this project, and it's going to cost around a billion dollars to build," says Greeson.

To that end, the team at Project Tundra, together with collaborators from the University of North Dakota and two industry partners, is currently working on securing permits and figuring out detailed engineering plans so that they can present a comprehensive risk assessment to potential investors. Greeson estimates it will take two years to raise the capital needed and another three to retrofit the plant with the necessary technology. If so, Young Station could become the world's largest power plant-based carbon capture facility as early as 2025.