Anthropogenic climate change is driving the need for rapid decarbonization of many industrial sectors, led by the global power generation industry.  While nuclear energy is garnering additional support as a key tool to decarbonize, many governments still consider adding more renewable energy capacity as their first choice for clean energy.  However, renewable energy’s intermittent generating profile oftentimes leaves baseload nuclear generators with abundant, unsellable electricity during peak renewable supply periods, which erodes nuclear plant profitability.  To yield a step change in mitigating CO2 emissions while also providing nuclear operators with a new, potentially lucrative and steady revenue stream, Direct Air Capture (DAC) is being evaluated by scientists and industry alike to become a new, highly effective solution.  Although DAC technology is in its developmental infancy, the technology has the potential to curb total atmospheric carbon content, mitigate the effects of climate change, and further enhance the value proposition posed by emissions-free, baseload nuclear power generation.

The basic concept of DAC is to use carbon-free energy, like nuclear power, to capture CO2 in the atmosphere, thus reducing the amount of CO2 that leads to climate change.  There are two predominant DAC methods under development today: liquid and solid DAC systems.  Liquid DAC systems pass ambient air across chemical solutions, which binds atmospheric CO2 to the aqueous solutions for further processing.  Meanwhile, solid DAC uses a series of physical filters and membranes under vacuum to pry CO2 molecules from forced airflow, which again can be collected for storage or resale.  Capturing CO2 via DAC is highly energy intensive, which makes the process quite expensive.  Thus, the key to successful DAC deployment is that the power used to drive the air capture units be cost effective and emissions-free from the start.  Carbon-free nuclear power plants paired with DAC technology can not only reduce atmospheric carbon, but also opens nuclear operators to new potentially lucrative revenue streams, including: selling DAC-linked carbon offsets or mitigation certificates in international markets; receiving policy-based subsidies for operating DAC units; and/or selling CO2 as a raw material to industrial end-users.

Carbon offsets and credits are effectively tradable “rights” certificates designed to offset a buyer’s CO2 emissions with an equal amount of CO2 reductions elsewhere.  Traditionally, these offsets fund initiatives like reforestation projects, renewable energy expansions, and/or bolster the use of carbon-sequestering agricultural practices.  There are two primary carbon markets today: the Compliance Carbon Offset Markets (CCM) and the Voluntary Carbon Offset Markets (VCM).  CCM is the larger and more mature of the two markets, consisting of carbon cap-and-trade emissions rights established by governments to meet climate ambitions.  This market is estimated at almost $300 billion annually.  VCM, on the other hand, is a newer market that is used at the discretion of companies or individuals to trade carbon credits to offset total emissions.  Consulting firm BCG estimates that while the total VCM was worth only ~$2 billion in 2021, the market could grow to as much as $40 billion annually by 2030.  Naturally, CCM and VCM are both considered controversial topics due to a lack of standard international carbon accounting methods and for the misuse of carbon offsets as a tool for “greenwashing.”  Despite carbon offset’s shortcomings, all leading international forecasts predict global carbon offset markets to grow exponentially as the markets mature and penetrate new industries.  It should be noted here that the pricing spread for carbon offsets can be staggering, ranging from less than $0.02 per tonne for reforestation projects to as much as $1,200 per tonne of CO2 removed by DAC systems.  However, due to the infancy of DAC technology, carbon offsets are rarely geared toward the immediate removal of CO2 from the atmosphere, but this is set to change with technological innovation and wider industry adoption.

Another potentially lucrative revenue stream posed by nuclear DAC is to capture and sell emissions-free CO2 supplies as a commodity to industrial end users.  The International Energy Agency (IEA) estimates that the market for CO2 raw materials is poised to boom in the coming decades, led by demand from the fertilizer industry, as well as from projected future markets ranging from chemical production industries, synthetic fuels, and CO2 sequestered in future building materials.  Today, approximately 230 million tonnes of CO2 (Mt CO2) are consumed as a commodity each year, led by the fertilizer industry, which accounts for about 130 Mt CO2 per year.  IEA estimates that global consumption of CO2 as a commodity is expected to grow steadily over the coming decades driven by agriculture and enhanced oil recovery operations.

It must be emphasized that carbon removal technologies like DAC are not viewed as an alternative to cutting emissions, but they can be an important part of the suite of technology options used to achieve climate targets.  As of late 2022, IEA counted just 18 DAC facilities operating the world over, extracting a paltry 0.01 Mt CO2 out of the atmosphere annually.  IEA estimates that DAC technologies must grow to begin pulling more than 60 Mt CO2 out of the atmosphere annually by 2030 just to remain on track to meet 2050 Net Zero Emissions Scenario targets.  Obviously, there is a lot of work to be done.  But large companies like Google, Microsoft, and others are investing in DAC tech to help offset their carbon footprints.  Thus, it is logical to assume that as DAC technology, processes, and know-how scales up, the stable, clean, and reliable energy provided by carbon-free nuclear power plants stands to benefit.

To that end, several utilities are now investigating the potential to pair their nuclear power plants with DAC systems to help decarbonize the planet.  The U.S.’ largest nuclear power operator, Constellation Energy, announced in 2022 that it won a grant from the U.S. Department of Energy (DOE) to determine the feasibility of linking Carbon Engineering’s DAC technology with the Byron nuclear power plant in northern Illinois.  Under that program, Constellation aims to study the feasibility of using Carbon Engineering’s DAC process to introduce a chemical solution to the water that flows through the plant’s main condenser.  After passing through the condenser, the chemically-charged water would travel out to the plant’s cooling towers, where CO2 in the air attaches itself to the chemical solution thereby becoming captured and sequestered for later use.  The study focuses on how the Byron nuclear power plant could pull up to 250,000 tonnes of CO2 from the air each year.

In the UK, EDF Energy is currently working with a group of leading industrial partners under a £3 million government grant to develop plans for a DAC unit powered by the proposed Sizewell C nuclear power plant in Suffolk, England.  Under the project, EDF Energy is investigating how to use heat produced by the planned two EPRs at Sizewell C to drive a DAC unit capable of extracting 100 tonnes of CO2 from the atmosphere each year.  Should the planned pilot DAC system prove successful, EDF Energy believes a scaled-up version of the DAC unit could one day capture up to 1.5 Mt CO2 each year – equivalent to offsetting the total emissions of the UK’s railway transport system.

The benefits of using nuclear power plants linked with DAC technology are numerous and far-reaching.  This combination can help to reduce carbon emissions, address the issue of carbon sequestration, create new applications for nuclear energy, while simultaneously reducing reliance on fossil fuels.  While there are certainly challenges ahead, the potential benefits are too significant to ignore.

This article was originally published in the March 27, 2023 issue of the Ux Weekly.

Philip Johnson is UxC, LLC’s Senior Vice President, Fuel Cycle. In his current capacity, Philip is a key contributor to many UxC publications, with a distinct focus on the front-end of the nuclear fuel cycle. Mr. Jonson also works on the demand and policy sides of the nuclear industry, researching next-generation nuclear technologies, as well as the future of non-grid applications for nuclear energy like hydrogen, direct air capture, process heat, and nuclear desalination, among others. Philip has been interviewed by a number of leading publications during his tenure at UxC, including The Wall Street Journal, TED, Investing News, and others, as well as being a guest on the highly acclaimed Titans of Nuclear Podcast in 2022. He holds a Bachelor’s degree in Economics from Georgia State University's Andrew Young School of Policy Studies, as well as a minor in English.