Minnkota Power Cooperative plans to retrofit the Milton R. Young coal-powered power plant and turn it into the largest carbon capture facility of its kind.
The local utility, aiming to raise the $1bn the project requires, is targeting more than 90% capture of carbon dioxide (CO2) from the plant’s 455MW unit.
David Greeson, a Consultant on Project Tundra said: “The company is 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.”
The majority of coal-fired plants in the US are reaching middle age. The Young station embodies 1970s technology, which makes upgrading these vintage plants with CCS a costly proposition.
Moreover, a coal-fired power plant fitted with CCS is more expensive to run. A coal plant uses between 5-9% of the electricity it generates to run the equipment it needs to operate—the so called “parasitic load.” Adding carbon capture, an energy- and water-intensive process, can push this parasitic load up to as much as 33%.
This expense is even harder to rationalise in parts of the country well-suited for use of renewables. North Dakota, for instance, gets a large amount of wind that can provide electricity to the grid at very low market prices. This means that consumers who get their power from a coal plant are paying a lot more than they would otherwise.
James Mulligan, Senior Associate at the World Resources Institute, said replacing coal and other fossil fuels with renewables isn’t a straightforward solution. “The question becomes: ‘Is there actually an opportunity to do that politically?”
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.
According to Institute for Energy Economics and Financial Analysis (IEEFA) estimates, that more than triples the cost of electricity generated at a coal plant, from $30 to $96 per 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.
Carbon capture projects such as Project Tundra form part of the multi-prong approach the United States needs to adopt in order to achieve its 2050 carbon-neutrality goal of emitting 2GT of CO2 per year.
David Schlissel, Director of Resource Planning Analysis at IEEFA, believes adding carbon capture is just a way of “bailing out old, expensive, inefficient coal plants.”
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,” he said.
Greeson disagrees. Project Tundra has already received $9.8m from the Department of Energy alongside $15m from North Dakota’s Lignite Research Fund. With additional funding from the 45Q tax credit scheme, he believes the project will secure the money it needs to begin construction.
Under the scheme, investors will receive $50 for every metric tonne of CO2 sequestered and stored. The plan is for Project Tundra to capture 3.5m tonnes of CO2 annually and the subsidy will last for 12 years. “So that’s $2.1 billion available in tax credits for this project,” says Greeson, “and it’s going to cost around a billion dollars to build.”
To that end, the team at Project Tundra, together with collaborators from the University of North Dakota and two industry partners, are 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, meaning Young Station could become the world’s largest power plant-based carbon capture facility as early as 2025.
